Wall-E3 Replacing Mega 2560 With Teensy 3.5

Posted 23 October, 2021

For some time now, I have been contemplating a replacement for the outdated and obsolete Mega 2560 micro-controller as the main controller module of my autonomous wall-following robot. The robot actually sports three controllers – the Mega 2560 main controller runs the overall operating system, drives the motors, and manages the speaker, the front-facing LIDAR unit, and a number of LEDs. A Teensy 3.2 manages the forward-facing IR-LED charging station beacon detection/homing algorithm, and a Teensy 3.5 manages the seven VL53L0X LIDAR distance measuring modules. So, it would make a lot of sense to replace the 2560 with another Teensy, making all the software consistent, and giving the robot a significant boost in computing power. A Teensy 3.5 at 120MHz runs at almost 10 times the 16MHz rate of the 2560, has twice the Flash memory (512K vs 256) and 32 times the RAM (256K vs 8). However, until recently (see this post) it has been very difficult/impossible to perform over-the-air (OTA) firmware updates with any of the Teensy products – a deal-breaker for me as I do that quite often with Wall-E2. Now that OTA capability has been demonstrated, the only remaining hurdle was whether or not a Teensy 3.5 has sufficient I/O to replace the Mega 2560. To address this question I created an Excel spreadsheet to document the current I/O assignments of the 2560 and then tentatively assigned Teensy 3.5 pins to match, as shown below.

As can be seen from the above, the Teensy 3.5 has plenty of pins left over after all currently assigned Mega 2560 pin assignments have been covered, so that problem goes away too.

The last piece of the puzzle was just the inconvenience of changing out a currently-working Mega 2560 just to gain performance that may or may not really be necessary. However, now that I have decided to redo the entire chassis to address the turn side-slip problem (see this post), I plan to use the opportunity to start fresh with a Teensy 3.5 as the main controller and work out any problems with just the chassis, the motors and motor drivers and the Teensy before moving on to implementing the rest of Wall-E2’s capabilities.

Motor Drivers for Wall-E3:

I have a bunch of motor driver modules left over from an earlier motor driver study, so I decided to use two of the Pololu VNH5019 motor driver modules for Wall-E3 – one for the two left motors, and one for the two right motors.

01 November 2021 Update:

The first step in bringing up the Wall-E3 robot was to assemble a very basic system on a simulated chassis bottom plate, as shown in the following photo:

Prototype Wall-E3 System on simulated chassis baseplate

The basic system consists of a TP5100 charger system and a 8.4V 7200 mAH battery pack, an Adafruit 1NA169 high-side current sensor, a Teensy 3.5 and a auxiliary board containing a 5V LDO regulator and a HC-05 Bluetooth module. The Teensy’s program at this stage consists of the OTA update code developed earlier in this post and this post, plus a few lines to read the current sensor output, convert it to a current value, and send it to the BT serial port. Here’s the program:

/*
    Name:       T35_WallE3_V1.ino
    Created:	10/25/2021 2:37:04 PM
    Author:     FRANKNEWXPS15\Frank

    10/30/21 - Added TeensyOTADemo code for basic OTA updates
*/

/*
    Name:       TeensyOTADemo.ino
    Created:	10/9/2021 11:18:19 AM
    Author:     FRANKNEWXPS15\Frank

    This program demonstrates the use of 'board.txt' post-build instructions in
    conjunction with a small C# command-line program for seamless 'over-the-air' (OTA)
    firmware update for Teensy modules.

    Implementation of OTA update requires that Joe Pasquariello's 'FlasherX'
    code be added to the Teensy sketch as it is below, and some code to allow
    an external serial communications program to trigger the update process.

    In the demo sketch below, the 'FlasherX' additions are the '#include FlasherTxx.h'
    line and the addition of the FlasherX specific code at the bottom. The trigger
    mechanism is provided by the 'CheckForUserInput();' call in loop.  If the ASCII
    code for 'U' or 'u' is present on Serial1, the update process will be launched.

*/

#include "FlashTxx.h"		// TLC/T3x/T4x flash primitives
#include <elapsedMillis.h>

elapsedMillis MsecSinceLastLEDToggle; //used for LED blink timer
const double AREF = 3.3; //teensy default for analog inputs
const double AmpsPerVolt = 1.00; //default 10K Rs
const int MAX_AD_COUNT = 1023;
const double VoltsPerCount = AREF / MAX_AD_COUNT;
const int ItotPin = A18;

//Stream* FTDIport = &Serial1;	// Serial (USB) or Serial1, Serial2, etc. (UART)

#pragma region OTA UPDATE
//******************************************************************************
// hex_info_t	struct for hex record and hex file info
//******************************************************************************
typedef struct {	// 
  char* data;		// pointer to array allocated elsewhere
  unsigned int addr;	// address in intel hex record
  unsigned int code;	// intel hex record type (0=data, etc.)
  unsigned int num;	// number of data bytes in intel hex record

  uint32_t base;	// base address to be added to intel hex 16-bit addr
  uint32_t min;		// min address in hex file
  uint32_t max;		// max address in hex file

  int eof;		// set true on intel hex EOF (code = 1)
  int lines;		// number of hex records received  
} hex_info_t;

void read_ascii_line(Stream* serial, char* line, int maxbytes);
int  parse_hex_line(const char* theline, char* bytes,
  unsigned int* addr, unsigned int* num, unsigned int* code);
int  process_hex_record(hex_info_t* hex);
void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size);

uint32_t buffer_addr, buffer_size; //09/20/21 copied from FlasherX - loop()
#pragma endregion OTA UPDATE

void setup()
{
  Serial.begin(115200);
  delay(2000); //10/06/21 - just use fixed delay instead

  Serial1.begin(115200); //used HC-05 'AT' commands to set this speed
  while (!Serial1) {}

  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(ItotPin, INPUT); //I_total 1V/Amp
  //analogReadAveraging(4);

  MsecSinceLastLEDToggle = 0;

  Serial1.printf("Msec\tADVal\tTotVolts\tTotAmps\n");
}

void loop()
{
  if (Serial1.available())
  {
    CheckForUserInput();
  }

  if (MsecSinceLastLEDToggle >= 200)
  {
    MsecSinceLastLEDToggle -= 200;
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));

    //11/01/21 read I_tot value & print out as current
    int ItotVal = analogRead(ItotPin);
    double ItotVolts = ItotVal * VoltsPerCount;
    double ItotAmps = ItotVolts * AmpsPerVolt;
    Serial1.printf("%lu\t%d\t%2.2f\t%2.2f\n", millis(), ItotVal, ItotVolts, ItotAmps);

  }
}
void CheckForUserInput()
{
  const int bufflen = 80;
  char buff[bufflen];
  memset(buff, 0, bufflen);
  //const char s[2] = ",";

  if (Serial1.available() > 0)
  {
    // read the incoming byte:
    int incomingByte = Serial1.read();

    // say what you got:
    Serial1.print("I received: ");
    Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20

    //02/18/20 experiment with multiple commands
    switch (incomingByte)
    {
    case 0x55: //ASCII 'U'
    case 0x75: //ASCII 'u'
      Serial1.println(F("Start Program Update - Send new HEX file!"));


      //09/20/21 copied from FlasherX - loop()
      if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)
      {
        Serial1.printf("unable to create buffer\n");
        Serial1.flush();
        for (;;) {}
      }

      Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",
        buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",
        buffer_addr, buffer_addr + buffer_size);

      //09/20/21 clear the serial buffer
      while (Serial1.available())
      {
        Serial1.read();
      }

      // receive hex file via serial, write new firmware to flash, clean up, reboot
      update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success

      // return from update_firmware() means error or user abort, so clean up and
      // reboot to ensure that static vars get boot-up initialized before retry
      Serial1.printf("erase FLASH buffer / free RAM buffer...\n");
      firmware_buffer_free(buffer_addr, buffer_size);
      Serial1.flush();
      REBOOT;
      break;
    }
  }
}

#pragma region FLASHER_X

//09/20/21 copied from FlasherX
//******************************************************************************
// update_firmware()	read hex file and write new firmware to program flash
//******************************************************************************
void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size)
{
  static char line[96];					// buffer for hex lines
  static char data[32] __attribute__((aligned(8)));	// buffer for hex data
  hex_info_t hex = {					// intel hex info struct
    data, 0, 0, 0,					//   data,addr,num,code
    0, 0xFFFFFFFF, 0, 					//   base,min,max,
    0, 0						//   eof,lines
  };

  serial->printf("waiting for hex lines...\n");

  // read and process intel hex lines until EOF or error
//DEBUG!!
  //int line_num = 0;
//DEBUG!!
  long int start_msec = 0;
  bool bFirstTime = true;
  while (!hex.eof) {

    read_ascii_line(serial, line, sizeof(line));

    if (bFirstTime)
    {
      start_msec = millis();
      bFirstTime = false;
    }

    //DEBUG!!
        //serial->printf("%d: %s\n", line_num, line);
        //line_num++;
    //DEBUG!!

        //10/02/21 gfp added for visual xfer confirmation
    if (hex.lines % 10 == 0)
    {
      digitalWriteFast(LED_BUILTIN, !digitalReadFast(LED_BUILTIN));
    }

    // reliability of transfer via USB is improved by this printf/flush
    if (serial == (Stream*)&Serial)
    {
      serial->printf("%s\n", line);
      serial->flush();
    }

    if (parse_hex_line((const char*)line, hex.data, &hex.addr, &hex.num, &hex.code) == 0) {
      serial->printf("abort - bad hex line %s\n", line);
      return;
    }
    else if (process_hex_record(&hex) != 0) { // error on bad hex code
      serial->printf("abort - invalid hex code %d\n", hex.code);
      return;
    }
    else if (hex.code == 0) { // if data record
      uint32_t addr = buffer_addr + hex.base + hex.addr - FLASH_BASE_ADDR;
      if (hex.max > (FLASH_BASE_ADDR + buffer_size)) {
        serial->printf("abort - max address %08lX too large\n", hex.max);
        return;
      }
      else if (!IN_FLASH(buffer_addr)) {
        memcpy((void*)addr, (void*)hex.data, hex.num);
      }
      else if (IN_FLASH(buffer_addr)) {
        int error = flash_write_block(addr, hex.data, hex.num);
        if (error) {
          serial->printf("abort - error %02X in flash_write_block()\n", error);
          return;
        }
      }
    }
    hex.lines++;
  }

  //serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX)\n",
  //  hex.lines, hex.max - hex.min, hex.min, hex.max);
  serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX), %lu Msec\n",
    hex.lines, hex.max - hex.min, hex.min, hex.max, millis() - start_msec);

  // check FSEC value in new code -- abort if incorrect
#if defined(KINETISK) || defined(KINETISL)
  uint32_t value = *(uint32_t*)(0x40C + buffer_addr);
  if (value == 0xfffff9de) {
    serial->printf("new code contains correct FSEC value %08lX\n", value);
  }
  else {
    serial->printf("abort - FSEC value %08lX should be FFFFF9DE\n", value);
    return;
  }
#endif

  // check FLASH_ID in new code - abort if not found
  if (check_flash_id(buffer_addr, hex.max - hex.min)) {
    serial->printf("new code contains correct target ID %s\n", FLASH_ID);
  }
  else {
    serial->printf("abort - new code missing string %s\n", FLASH_ID);
    return;
  }

  // get user input to write to flash or abort
  int user_lines = -1;
  while (user_lines != hex.lines && user_lines != 0) {
    serial->printf("enter %d to flash or 0 to abort\n", hex.lines);
    read_ascii_line(serial, line, sizeof(line));
    sscanf(line, "%d", &user_lines);
  }

  if (user_lines == 0) {
    serial->printf("abort - user entered 0 lines\n");
    return;
  }

  // move new program from buffer to flash, free buffer, and reboot
  //serial->printf("user entered %d lines\n", user_lines);
  flash_move(FLASH_BASE_ADDR, buffer_addr, hex.max - hex.min);

  // should not return from flash_move(), but put REBOOT here as reminder
  REBOOT;
}

//******************************************************************************
// read_ascii_line()	read ascii characters until '\n', '\r', or max bytes
//******************************************************************************
void read_ascii_line(Stream* serial, char* line, int maxbytes)
{
  int c = 0, nchar = 0;
  while (nchar < maxbytes && !(c == '\n' || c == '\r')) {
    if (serial->available()) {
      c = serial->read();
      line[nchar++] = c;
    }
  }
  line[nchar - 1] = 0;	// null-terminate
}

//******************************************************************************
// process_hex_record()		process record and return okay (0) or error (1)
//******************************************************************************
int process_hex_record(hex_info_t* hex)
{
  if (hex->code == 0) { // data -- update min/max address so far
    if (hex->base + hex->addr + hex->num > hex->max)
      hex->max = hex->base + hex->addr + hex->num;
    if (hex->base + hex->addr < hex->min)
      hex->min = hex->base + hex->addr;
  }
  else if (hex->code == 1) { // EOF (:flash command not received yet)
    hex->eof = 1;
  }
  else if (hex->code == 2) { // extended segment address (top 16 of 24-bit addr)
    hex->base = ((hex->data[0] << 8) | hex->data[1]) << 4;
  }
  else if (hex->code == 3) { // start segment address (80x86 real mode only)
    return 1;
  }
  else if (hex->code == 4) { // extended linear address (top 16 of 32-bit addr)
    hex->base = ((hex->data[0] << 8) | hex->data[1]) << 16;
  }
  else if (hex->code == 5) { // start linear address (32-bit big endian addr)
    hex->base = (hex->data[0] << 24) | (hex->data[1] << 16)
      | (hex->data[2] << 8) | (hex->data[3] << 0);
  }
  else {
    return 1;
  }

  return 0;
}

//******************************************************************************
// Intel Hex record foramt:
//
// Start code:  one character, ASCII colon ':'.
// Byte count:  two hex digits, number of bytes (hex digit pairs) in data field.
// Address:     four hex digits
// Record type: two hex digits, 00 to 05, defining the meaning of the data field.
// Data:        n bytes of data represented by 2n hex digits.
// Checksum:    two hex digits, computed value used to verify record has no errors.
//
// Examples:
//  :10 9D30 00 711F0000AD38000005390000F5460000 35
//  :04 9D40 00 01480000 D6
//  :00 0000 01 FF
//******************************************************************************

/* Intel HEX read/write functions, Paul Stoffregen, paul@ece.orst.edu */
/* This code is in the public domain.  Please retain my name and */
/* email address in distributed copies, and let me know about any bugs */

/* I, Paul Stoffregen, give no warranty, expressed or implied for */
/* this software and/or documentation provided, including, without */
/* limitation, warranty of merchantability and fitness for a */
/* particular purpose. */

// type modifications by Jon Zeeff

/* parses a line of intel hex code, stores the data in bytes[] */
/* and the beginning address in addr, and returns a 1 if the */
/* line was valid, or a 0 if an error occured.  The variable */
/* num gets the number of bytes that were stored into bytes[] */

#include <stdio.h>		// sscanf(), etc.
#include <string.h>		// strlen(), etc.

int parse_hex_line(const char* theline, char* bytes,
  unsigned int* addr, unsigned int* num, unsigned int* code)
{
  unsigned sum, len, cksum;
  const char* ptr;
  int temp;

  *num = 0;
  if (theline[0] != ':')
    return 0;
  if (strlen(theline) < 11)
    return 0;
  ptr = theline + 1;
  if (!sscanf(ptr, "%02x", &len))
    return 0;
  ptr += 2;
  if (strlen(theline) < (11 + (len * 2)))
    return 0;
  if (!sscanf(ptr, "%04x", (unsigned int*)addr))
    return 0;
  ptr += 4;
  /* Serial.printf("Line: length=%d Addr=%d\n", len, *addr); */
  if (!sscanf(ptr, "%02x", code))
    return 0;
  ptr += 2;
  sum = (len & 255) + ((*addr >> 8) & 255) + (*addr & 255) + (*code & 255);
  while (*num != len)
  {
    if (!sscanf(ptr, "%02x", &temp))
      return 0;
    bytes[*num] = temp;
    ptr += 2;
    sum += bytes[*num] & 255;
    (*num)++;
    if (*num >= 256)
      return 0;
  }
  if (!sscanf(ptr, "%02x", &cksum))
    return 0;

  if (((sum & 255) + (cksum & 255)) & 255)
    return 0;     /* checksum error */
  return 1;
}
#pragma endregion FLASHER_X

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Name: T35_WallE3_V1.ino

Created: 10/25/2021 2:37:04 PM

Author: FRANKNEWXPS15\Frank

10/30/21 - Added TeensyOTADemo code for basic OTA updates

Name: TeensyOTADemo.ino

Created: 10/9/2021 11:18:19 AM

Author: FRANKNEWXPS15\Frank

This program demonstrates the use of 'board.txt' post-build instructions in

conjunction with a small C# command-line program for seamless 'over-the-air' (OTA)

firmware update for Teensy modules.

Implementation of OTA update requires that Joe Pasquariello's 'FlasherX'

code be added to the Teensy sketch as it is below, and some code to allow

an external serial communications program to trigger the update process.

In the demo sketch below, the 'FlasherX' additions are the '#include FlasherTxx.h'

line and the addition of the FlasherX specific code at the bottom. The trigger

mechanism is provided by the 'CheckForUserInput();' call in loop. If the ASCII

code for 'U' or 'u' is present on Serial1, the update process will be launched.

#include "FlashTxx.h" // TLC/T3x/T4x flash primitives

#include <elapsedMillis.h>

elapsedMillis MsecSinceLastLEDToggle; //used for LED blink timer

const double AREF = 3.3; //teensy default for analog inputs

const double AmpsPerVolt = 1.00; //default 10K Rs

const int MAX_AD_COUNT = 1023;

const double VoltsPerCount = AREF / MAX_AD_COUNT;

const int ItotPin = A18;

//Stream* FTDIport = &Serial1; // Serial (USB) or Serial1, Serial2, etc. (UART)

#pragma region OTA UPDATE

//******************************************************************************

// hex_info_t struct for hex record and hex file info

//******************************************************************************

typedef struct { //

char* data; // pointer to array allocated elsewhere

unsigned int addr; // address in intel hex record

unsigned int code; // intel hex record type (0=data, etc.)

unsigned int num; // number of data bytes in intel hex record

uint32_t base; // base address to be added to intel hex 16-bit addr

uint32_t min; // min address in hex file

uint32_t max; // max address in hex file

int eof; // set true on intel hex EOF (code = 1)

int lines; // number of hex records received

} hex_info_t;

void read_ascii_line(Stream* serial, char* line, int maxbytes);

int parse_hex_line(const char* theline, char* bytes,

unsigned int* addr, unsigned int* num, unsigned int* code);

int process_hex_record(hex_info_t* hex);

void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size);

uint32_t buffer_addr, buffer_size; //09/20/21 copied from FlasherX - loop()

#pragma endregion OTA UPDATE

void setup()

{

Serial.begin(115200);

delay(2000); //10/06/21 - just use fixed delay instead

Serial1.begin(115200); //used HC-05 'AT' commands to set this speed

while (!Serial1) {}

pinMode(LED_BUILTIN, OUTPUT);

pinMode(ItotPin, INPUT); //I_total 1V/Amp

//analogReadAveraging(4);

MsecSinceLastLEDToggle = 0;

Serial1.printf("Msec\tADVal\tTotVolts\tTotAmps\n");

}

void loop()

{

if (Serial1.available())

{

CheckForUserInput();

}

if (MsecSinceLastLEDToggle >= 200)

{

MsecSinceLastLEDToggle -= 200;

digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));

//11/01/21 read I_tot value & print out as current

int ItotVal = analogRead(ItotPin);

double ItotVolts = ItotVal * VoltsPerCount;

double ItotAmps = ItotVolts * AmpsPerVolt;

Serial1.printf("%lu\t%d\t%2.2f\t%2.2f\n", millis(), ItotVal, ItotVolts, ItotAmps);

}

void CheckForUserInput()

{

const int bufflen = 80;

char buff[bufflen];

memset(buff, 0, bufflen);

//const char s[2] = ",";

if (Serial1.available() > 0)

{

// read the incoming byte:

int incomingByte = Serial1.read();

// say what you got:

Serial1.print("I received: ");

Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20

//02/18/20 experiment with multiple commands

switch (incomingByte)

{

case 0x55: //ASCII 'U'

case 0x75: //ASCII 'u'

Serial1.println(F("Start Program Update - Send new HEX file!"));

//09/20/21 copied from FlasherX - loop()

if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)

{

Serial1.printf("unable to create buffer\n");

Serial1.flush();

for (;;) {}

}

Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",

buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",

buffer_addr, buffer_addr + buffer_size);

//09/20/21 clear the serial buffer

while (Serial1.available())

{

Serial1.read();

}

// receive hex file via serial, write new firmware to flash, clean up, reboot

update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success

// return from update_firmware() means error or user abort, so clean up and

// reboot to ensure that static vars get boot-up initialized before retry

Serial1.printf("erase FLASH buffer / free RAM buffer...\n");

firmware_buffer_free(buffer_addr, buffer_size);

Serial1.flush();

REBOOT;

break;

}

#pragma region FLASHER_X

//09/20/21 copied from FlasherX

//******************************************************************************

// update_firmware() read hex file and write new firmware to program flash

//******************************************************************************

void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size)

{

static char line[96]; // buffer for hex lines

static char data[32] __attribute__((aligned(8))); // buffer for hex data

hex_info_t hex = { // intel hex info struct

data, 0, 0, 0, // data,addr,num,code

0, 0xFFFFFFFF, 0, // base,min,max,

0, 0 // eof,lines

};

serial->printf("waiting for hex lines...\n");

// read and process intel hex lines until EOF or error

//DEBUG!!

//int line_num = 0;

//DEBUG!!

long int start_msec = 0;

bool bFirstTime = true;

while (!hex.eof) {

read_ascii_line(serial, line, sizeof(line));

if (bFirstTime)

{

start_msec = millis();

bFirstTime = false;

}

//DEBUG!!

//serial->printf("%d: %s\n", line_num, line);

//line_num++;

//DEBUG!!

//10/02/21 gfp added for visual xfer confirmation

if (hex.lines % 10 == 0)

{

digitalWriteFast(LED_BUILTIN, !digitalReadFast(LED_BUILTIN));

}

// reliability of transfer via USB is improved by this printf/flush

if (serial == (Stream*)&Serial)

{

serial->printf("%s\n", line);

serial->flush();

}

if (parse_hex_line((const char*)line, hex.data, &hex.addr, &hex.num, &hex.code) == 0) {

serial->printf("abort - bad hex line %s\n", line);

return;

}

else if (process_hex_record(&hex) != 0) { // error on bad hex code

serial->printf("abort - invalid hex code %d\n", hex.code);

return;

}

else if (hex.code == 0) { // if data record

uint32_t addr = buffer_addr + hex.base + hex.addr - FLASH_BASE_ADDR;

if (hex.max > (FLASH_BASE_ADDR + buffer_size)) {

serial->printf("abort - max address %08lX too large\n", hex.max);

return;

}

else if (!IN_FLASH(buffer_addr)) {

memcpy((void*)addr, (void*)hex.data, hex.num);

}

else if (IN_FLASH(buffer_addr)) {

int error = flash_write_block(addr, hex.data, hex.num);

if (error) {

serial->printf("abort - error %02X in flash_write_block()\n", error);

return;

}

hex.lines++;

}

//serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX)\n",

// hex.lines, hex.max - hex.min, hex.min, hex.max);

serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX), %lu Msec\n",

hex.lines, hex.max - hex.min, hex.min, hex.max, millis() - start_msec);

// check FSEC value in new code -- abort if incorrect

#if defined(KINETISK) || defined(KINETISL)

uint32_t value = *(uint32_t*)(0x40C + buffer_addr);

if (value == 0xfffff9de) {

serial->printf("new code contains correct FSEC value %08lX\n", value);

}

else {

serial->printf("abort - FSEC value %08lX should be FFFFF9DE\n", value);

return;

}

#endif

// check FLASH_ID in new code - abort if not found

if (check_flash_id(buffer_addr, hex.max - hex.min)) {

serial->printf("new code contains correct target ID %s\n", FLASH_ID);

}

else {

serial->printf("abort - new code missing string %s\n", FLASH_ID);

return;

}

// get user input to write to flash or abort

int user_lines = -1;

while (user_lines != hex.lines && user_lines != 0) {

serial->printf("enter %d to flash or 0 to abort\n", hex.lines);

read_ascii_line(serial, line, sizeof(line));

sscanf(line, "%d", &user_lines);

}

if (user_lines == 0) {

serial->printf("abort - user entered 0 lines\n");

return;

}

// move new program from buffer to flash, free buffer, and reboot

//serial->printf("user entered %d lines\n", user_lines);

flash_move(FLASH_BASE_ADDR, buffer_addr, hex.max - hex.min);

// should not return from flash_move(), but put REBOOT here as reminder

REBOOT;

}

//******************************************************************************

// read_ascii_line() read ascii characters until '\n', '\r', or max bytes

//******************************************************************************

void read_ascii_line(Stream* serial, char* line, int maxbytes)

{

int c = 0, nchar = 0;

while (nchar < maxbytes && !(c == '\n' || c == '\r')) {

if (serial->available()) {

c = serial->read();

line[nchar++] = c;

}

line[nchar - 1] = 0; // null-terminate

}

//******************************************************************************

// process_hex_record() process record and return okay (0) or error (1)

//******************************************************************************

int process_hex_record(hex_info_t* hex)

{

if (hex->code == 0) { // data -- update min/max address so far

if (hex->base + hex->addr + hex->num > hex->max)

hex->max = hex->base + hex->addr + hex->num;

if (hex->base + hex->addr < hex->min)

hex->min = hex->base + hex->addr;

}

else if (hex->code == 1) { // EOF (:flash command not received yet)

hex->eof = 1;

}

else if (hex->code == 2) { // extended segment address (top 16 of 24-bit addr)

hex->base = ((hex->data[0] << 8) | hex->data[1]) << 4;

}

else if (hex->code == 3) { // start segment address (80x86 real mode only)

return 1;

}

else if (hex->code == 4) { // extended linear address (top 16 of 32-bit addr)

hex->base = ((hex->data[0] << 8) | hex->data[1]) << 16;

}

else if (hex->code == 5) { // start linear address (32-bit big endian addr)

hex->base = (hex->data[0] << 24) | (hex->data[1] << 16)

| (hex->data[2] << 8) | (hex->data[3] << 0);

}

else {

return 1;

}

return 0;

}

//******************************************************************************

// Intel Hex record foramt:

// Start code: one character, ASCII colon ':'.

// Byte count: two hex digits, number of bytes (hex digit pairs) in data field.

// Address: four hex digits

// Record type: two hex digits, 00 to 05, defining the meaning of the data field.

// Data: n bytes of data represented by 2n hex digits.

// Checksum: two hex digits, computed value used to verify record has no errors.

// Examples:

// :10 9D30 00 711F0000AD38000005390000F5460000 35

// :04 9D40 00 01480000 D6

// :00 0000 01 FF

//******************************************************************************

/* Intel HEX read/write functions, Paul Stoffregen, paul@ece.orst.edu */

/* This code is in the public domain. Please retain my name and */

/* email address in distributed copies, and let me know about any bugs */

/* I, Paul Stoffregen, give no warranty, expressed or implied for */

/* this software and/or documentation provided, including, without */

/* limitation, warranty of merchantability and fitness for a */

/* particular purpose. */

// type modifications by Jon Zeeff

/* parses a line of intel hex code, stores the data in bytes[] */

/* and the beginning address in addr, and returns a 1 if the */

/* line was valid, or a 0 if an error occured. The variable */

/* num gets the number of bytes that were stored into bytes[] */

#include <stdio.h> // sscanf(), etc.

#include <string.h> // strlen(), etc.

int parse_hex_line(const char* theline, char* bytes,

unsigned int* addr, unsigned int* num, unsigned int* code)

{

unsigned sum, len, cksum;

const char* ptr;

int temp;

*num = 0;

if (theline[0] != ':')

return 0;

if (strlen(theline) < 11)

return 0;

ptr = theline + 1;

if (!sscanf(ptr, "%02x", &len))

return 0;

ptr += 2;

if (strlen(theline) < (11 + (len * 2)))

return 0;

if (!sscanf(ptr, "%04x", (unsigned int*)addr))

return 0;

ptr += 4;

/* Serial.printf("Line: length=%d Addr=%d\n", len, *addr); */

if (!sscanf(ptr, "%02x", code))

return 0;

ptr += 2;

sum = (len & 255) + ((*addr >> 8) & 255) + (*addr & 255) + (*code & 255);

while (*num != len)

{

if (!sscanf(ptr, "%02x", &temp))

return 0;

bytes[*num] = temp;

ptr += 2;

sum += bytes[*num] & 255;

(*num)++;

if (*num >= 256)

return 0;

}

if (!sscanf(ptr, "%02x", &cksum))

return 0;

if (((sum & 255) + (cksum & 255)) & 255)

return 0; /* checksum error */

return 1;

}

#pragma endregion FLASHER_X

And here is some of the output:

I received: 55
Start Program Update - Send new HEX file!
buffer = 460K FLASH (0000D000 - 00080000)
waiting for hex lines...

hex file: 3194 lines 51048 bytes (00000000 - 0000C768), 13742 Msec
new code contains correct FSEC value FFFFF9DE
new code contains correct target ID fw_teensy35
enter 3194 to flash or 0 to abort
Msec    ADVal   TotVolts        TotAmps
2500    475     1.53    1.53
2700    465     1.50    1.50
2900    466     1.50    1.50
3100    499     1.61    1.61
3300    32      0.10    0.10
3500    459     1.48    1.48
3700    323     1.04    1.04
3900    473     1.53    1.53
4100    9       0.03    0.03
4300    317     1.02    1.02
4500    467     1.51    1.51
4700    460     1.48    1.48
4900    466     1.50    1.50
5100    262     0.85    0.85
5300    28      0.09    0.09
5500    467     1.51    1.51
5700    471     1.52    1.52
5900    469     1.51    1.51
6100    471     1.52    1.52

I received: 55

Start Program Update - Send new HEX file!

buffer = 460K FLASH (0000D000 - 00080000)

waiting for hex lines...

hex file: 3194 lines 51048 bytes (00000000 - 0000C768), 13742 Msec

new code contains correct FSEC value FFFFF9DE

new code contains correct target ID fw_teensy35

enter 3194 to flash or 0 to abort

Msec ADVal TotVolts TotAmps

2500 475 1.53 1.53

2700 465 1.50 1.50

2900 466 1.50 1.50

3100 499 1.61 1.61

3300 32 0.10 0.10

3500 459 1.48 1.48

3700 323 1.04 1.04

3900 473 1.53 1.53

4100 9 0.03 0.03

4300 317 1.02 1.02

4500 467 1.51 1.51

4700 460 1.48 1.48

4900 466 1.50 1.50

5100 262 0.85 0.85

5300 28 0.09 0.09

5500 467 1.51 1.51

5700 471 1.52 1.52

5900 469 1.51 1.51

6100 471 1.52 1.52

With this setup I noticed there were a lot of ‘dropouts’ in the sensor outputs, so I added a 1uF cap between the sensor Vout and GND. This seemed to cure the dropouts as shown in the next output snippet (after some charging time resulting in lower charging current)

Msec    ADVal   TotVolts        TotAmps
2500    265     0.85    0.85
2700    263     0.85    0.85
2900    266     0.86    0.86
3100    267     0.86    0.86
3300    269     0.87    0.87
3500    265     0.85    0.85
3700    266     0.86    0.86
3900    264     0.85    0.85
4100    266     0.86    0.86
4300    269     0.87    0.87
4500    268     0.86    0.86
4700    268     0.86    0.86
4900    265     0.85    0.85
5100    267     0.86    0.86
5300    266     0.86    0.86
5500    265     0.85    0.85
5700    267     0.86    0.86
5900    265     0.85    0.85
6100    263     0.85    0.85
6300    264     0.85    0.85
6500    266     0.86    0.86
6700    262     0.85    0.85
6900    261     0.84    0.84
7100    263     0.85    0.85
7300    259     0.84    0.84
7500    262     0.85    0.85
7700    261     0.84    0.84
7900    262     0.85    0.85
8100    262     0.85    0.85
8300    261     0.84    0.84
8500    261     0.84    0.84
8700    262     0.85    0.85
8900    260     0.84    0.84
9100    261     0.84    0.84
9300    258     0.83    0.83
9500    262     0.85    0.85
9700    258     0.83    0.83
9900    257     0.83    0.83
10100   259     0.84    0.84
10300   261     0.84    0.84

Msec ADVal TotVolts TotAmps

2500 265 0.85 0.85

2700 263 0.85 0.85

2900 266 0.86 0.86

3100 267 0.86 0.86

3300 269 0.87 0.87

3500 265 0.85 0.85

3700 266 0.86 0.86

3900 264 0.85 0.85

4100 266 0.86 0.86

4300 269 0.87 0.87

4500 268 0.86 0.86

4700 268 0.86 0.86

4900 265 0.85 0.85

5100 267 0.86 0.86

5300 266 0.86 0.86

5500 265 0.85 0.85

5700 267 0.86 0.86

5900 265 0.85 0.85

6100 263 0.85 0.85

6300 264 0.85 0.85

6500 266 0.86 0.86

6700 262 0.85 0.85

6900 261 0.84 0.84

7100 263 0.85 0.85

7300 259 0.84 0.84

7500 262 0.85 0.85

7700 261 0.84 0.84

7900 262 0.85 0.85

8100 262 0.85 0.85

8300 261 0.84 0.84

8500 261 0.84 0.84

8700 262 0.85 0.85

8900 260 0.84 0.84

9100 261 0.84 0.84

9300 258 0.83 0.83

9500 262 0.85 0.85

9700 258 0.83 0.83

9900 257 0.83 0.83

10100 259 0.84 0.84

10300 261 0.84 0.84

04 November 2021 Update:

I installed two Pololu VNH5019 drivers onto the prototype bottom plate, and copied the associated motor support code from my latest Wall-E2 version. I modified ‘SetLeftMotorDirAndSpeed(bool bIsFwd, int speed)’ and ‘SetRightMotorDirAndSpeed(bool bIsFwd, int speed)’ for the VNH5019 pinout and truth table, and that was pretty much all I had to do. Then I copied all of ‘CheckForUserInput()’ from Wall-E2 (and added the ‘U/u’ case for OTA updates) so I could control the motor direction and speed via the OTA serial connection, and the motors and drivers behaved pretty much right away. Here’s a short video showing the action:

05 November 2021 Update

I finally got the new 200 x 230 mm aluminum chassis finished, as shown in the following photo:

10 November 2021 Update:

After getting the new aluminum chassis fabricated, it was time to start populating it with subsystems from the prototype chassis and from Wall-E2. As shown in the following photo, the next big milestone was to populate it with four Pololu D-20 motors, the battery/charger and 5V LDO regulator subsystems, and the two Pololu VNH5019 motor drivers from the proto chassis. With the addition of four 3D printed wheels/tires from Wall-E2, and Wall-E3 was officially ‘mobile’!

As can be seen above, the Teensy 3.5 controller and its companion 5V LDO regulator board/HC-05 Bluetooth module were simply hot-glued to the battery pack for initial testing; they will be moved to the top plate next.

After successful movement tests with the above arrangement (see the companion post), the next step was to install the Teensy 3.5 controller and the LDO/HC-05 module on the top plate, and permanently install the charging connector and the ON/OFF switch. I decided that a single hole punched into the center rear of the top plate would suffice for bringing necessary wiring up from the internal battery/motor bay onto the top plate, and placing the hole toward the rear would allow the top plate to be removed and placed upside down at the back of the chassis to allow access to the battery/motor bay as needed. As shown in the following photo, the top plate is secured upside-down on the main chassis by two of the normal mounting screws, thus keeping the top-plate-mounted subsystems from contacting the ground.

Also note that the motor/battery bay is much cleaner than the Wall-E2 layout, even though both motor drivers are in this bay rather than mounted to the top plate as they are for Wall-E2. The next photos below show the chassis closed up with the Teensy 3.5 and the 5V LDO module mounted on the top plate, with the charging connector and the ON/OFF switch permanently installed.

Front & rear aspect views of the ‘closed’ chassis

After getting everything closed up, I re-ran the ‘spin turn’ trials, as shown below:

‘Spin Turn’ trials with T3.5 and 5V LDO mounted to top plate

At this point, there are only three significant modules (the MPU6050 IMU, the ‘Run Current’ 1NA169 high-side current sensor, and the charging station beacon homing module) remaining to install on the top plate. The first step will be to install and test the MPU6050, as that will give Wall-E3 the capability to do angle-controlled turns.

20 November 2021 Update:

As described in the companion post to this one, my plan is to move forward with the Teensy program (Teensy_MPU6050_DMP6_V3.ino) and the older I2CDevlib/MPU6050 library versions while waiting for Jeff Rowberg and company to figure out why the current versions of this library are no longer compatible with the Teensy 3.x line of microcontrollers.

The first step in this process is to remove the Arduino UNO/Wixel Shield module from the robot, and get the already-installed Teensy 3.5 talking to the already-installed MPU6050 module using the above mentioned Teensy_MPU6050_DMP6_V3.ino and the older I2CDevlib/MPU6050 library versions. Here’s the hardware layout:

Teensy 3.5, MPU6050, 5V LDO Regulator/HC-05 BT module, ‘I_Run’ current sensor

And here’s some output from Teensy_MPU6050_DMP6_V3.ino showing a ‘live’ connection to the MPU6050:

Opening port
Port open
In Setup
Testing device connections...
getDeviceID() returns 0X34
MPU6050 connection successful
Initializing DMP...
Enabling DMP...
DMP ready! Waiting for MPU6050 drift rate to settle...

MPU6050 Ready at 3.76 Sec
3973	0.19
4173	0.49
4375	0.80
4575	1.09
4775	1.35
4975	1.58
5175	1.78
5375	1.96
5575	2.12
5775	2.28
5975	2.43
6175	2.57
6375	2.66
6587	1.04
6764	-3.44
6964	-10.12
7164	-13.49
7364	-19.00
7564	-23.03
7768	-21.80
7968	-16.39
8168	-8.59
8368	0.90
8568	10.14
8768	15.36
8968	15.97
9168	14.49
9368	14.45
9568	13.57
9768	6.65
9970	-4.99
10170	-15.33
10370	-24.65
10570	-28.25
10770	-25.79
10970	-23.11
11170	-14.95
11370	-3.79
11570	9.58
11770	19.47
11973	23.61
12173	22.41
12373	21.69
12573	21.23
12773	20.94
12973	20.76
13173	20.67
13373	20.65
13573	20.66
13773	20.71
13975	20.77
14175	20.85
14375	20.95
14575	21.05
14775	21.15

Port closed

Opening port

Port open

In Setup

Testing device connections...

getDeviceID() returns 0X34

MPU6050 connection successful

Initializing DMP...

Enabling DMP...

DMP ready! Waiting for MPU6050 drift rate to settle...

MPU6050 Ready at 3.76 Sec

3973 0.19

4173 0.49

4375 0.80

4575 1.09

4775 1.35

4975 1.58

5175 1.78

5375 1.96

5575 2.12

5775 2.28

5975 2.43

6175 2.57

6375 2.66

6587 1.04

6764 -3.44

6964 -10.12

7164 -13.49

7364 -19.00

7564 -23.03

7768 -21.80

7968 -16.39

8168 -8.59

8368 0.90

8568 10.14

8768 15.36

8968 15.97

9168 14.49

9368 14.45

9568 13.57

9768 6.65

9970 -4.99

10170 -15.33

10370 -24.65

10570 -28.25

10770 -25.79

10970 -23.11

11170 -14.95

11370 -3.79

11570 9.58

11770 19.47

11973 23.61

12173 22.41

12373 21.69

12573 21.23

12773 20.94

12973 20.76

13173 20.67

13373 20.65

13573 20.66

13773 20.71

13975 20.77

14175 20.85

14375 20.95

14575 21.05

14775 21.15

Port closed

At this point, we have demonstrated we can talk to the MPU6050 using Jeff Rowberg’s (old) I2CDevlib library and can pull off yaw values, so we should also be able to do the same turn-rate-controlled turns as before.

So now I have a Teensy project (Teensy_MPU6050_DMP6_V3) that demonstrates a working interface to the MPU6050, a prior project (T35_WallE3_V1) that demonstrated Teensy OTA updates using an HC-05 Bluetooth module, and a Teensy project demonstrating turn-rate controlled turns using the MPU6050 (T35_MPU6050_Demo_V2). The next step is to create yet another new project, this time cleverly called ‘T35_WallE3_V2’, to merge all these features into one project, and then hopefully proceed from there.

When I created the T35_WallE3_V2 project, the first thing I did was copy in T35_WallE3_V1.ino and supporting files, and then I tested it to make sure everything was OK. However, this project wouldn’t connect to the MPU6050 even though I was sure it was using the older I2CDevlib files. After a very careful comparison, I found there were a very few differences. When I instead used the support files from my Teensy_MPU6050_DMP6_V3 project, then T35_WallE3_V2 was able to connect to the MPU6050. The i2Cdev.h/cpp files were essentially identical. The MPU6050.h/cpp files were essentially identical. The MPU6050_6Axis_MotionApps_V6_12.h files were essentially identical, so I’m not really sure why the magic happened — but it did!

So now the T35_WallE3_V2 talks to the MPU6050. Next I enabled ‘board.txt’ and verified that I can still do OTA firmware updates.

21 November 2021 (an almost palindromic date 21_11_21) Update:

After verifying OTA update capability with T35_WallE3_V2, I started porting in turn-rate control code from the Teensy_MPU6050_DMP6_V3 project, consisting mainly of the PID values empirically found in the companion ‘form-factor’ post, and the PIDCalcs() function.

Replaced T35_WallE3_V2 ‘CheckForUserInput()’ with version from T35_MPU6050_Demo_V2
Replaced T35_WallE3_V2 ‘PIDCalcs()’ with version from T35_MPU6050_Demo_V2
Replaced T35_WallE3_V2 ‘SpinTurn()’ with version from T35_MPU6050_Demo_V2 and added TURN_START_SPEED constant.
Updated TurnRate_Kp/Ki/Kd to 1.8/1.0/0.4

22 November 2021 Update:

At this point I have T35_WallE3_V2 to the point where I can do OTA firmware updates via the HC-05 Bluetooth link, and I can remotely command CW & CCW turns, forward and backward, speed up/down. Here’s the snapshot of the code at this point.

/*
    Name:       T35_WallE3_V2.ino
    Created:	11/20/2021 4:41:25 PM
    Author:     FRANKNEWXPS15\Frank
*/

/*
    Name:       T35_WallE3_V1.ino
    Created:	10/25/2021 2:37:04 PM
    Author:     FRANKNEWXPS15\Frank

    10/30/21 - Added TeensyOTADemo code for basic OTA updates
*/

/*
    Name:       TeensyOTADemo.ino
    Created:	10/9/2021 11:18:19 AM
    Author:     FRANKNEWXPS15\Frank

    This program demonstrates the use of 'board.txt' post-build instructions in
    conjunction with a small C# command-line program for seamless 'over-the-air' (OTA)
    firmware update for Teensy modules.

    Implementation of OTA update requires that Joe Pasquariello's 'FlasherX'
    code be added to the Teensy sketch as it is below, and some code to allow
    an external serial communications program to trigger the update process.

    In the demo sketch below, the 'FlasherX' additions are the '#include FlasherTxx.h'
    line and the addition of the FlasherX specific code at the bottom. The trigger
    mechanism is provided by the 'CheckForUserInput();' call in loop.  If the ASCII
    code for 'U' or 'u' is present on Serial1, the update process will be launched.

*/

#pragma region INCLUDES
#include "FlashTxx.h"		// TLC/T3x/T4x flash primitives
#include <elapsedMillis.h>
#include "MPU6050_6Axis_MotionApps_V6_12.h"  //changed to this version 10/05/19
#pragma endregion Includes


#pragma region DEFINES
//02/29/16 hardware defines
//#define NO_MOTORS
//#define IR_HOMING_ONLY

//#define NO_LIDAR
//#define NO_PINGS
//#define NO_IRDET //added 04/05/17 for daytime in-atrium testing (too much ambient IR)
//#define DISTANCES_ONLY //added 11/14/18 to just display distances in infinite loop
#define NO_STUCK //added 03/10/19 to disable 'stuck' detection
//#define BATTERY_DISCHARGE //added 03/04/20 to discharge battery safely
#define NO_POST //added 04/12/20 to skip all the POST checks

//11/07/2020 moved all I2C Address declarations here
#define IRDET_I2C_ADDR 0x08
#define MPU6050_I2C_ADDR 0x68

#pragma endregion Program #Defines

#pragma region PRE_SETUP
MPU6050 mpu(MPU6050_I2C_ADDR);
elapsedMillis MsecSinceLastLEDToggle; //used for LED blink timer
const double ADC_REF_VOLTS = 3.3; //teensy default for analog inputs
const double AmpsPerVolt = 1.00; //default 10K Rs
const int MAX_AD_COUNT = 1023;
const double VoltsPerCount = ADC_REF_VOLTS / MAX_AD_COUNT;

//Battery constants
const float ZENER_VOLTAGE_OFFSET = 5.84; //measured zener voltage

#pragma region PIN ASSIGNMENTS

//vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv//
//===================  START PIN ASSIGNMENTS ===================//
//vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv//

#pragma region MOTOR_PINS
//11/04/21 Now using Pololu VNH5019 drivers for all 4 motors
const int InA_Left = 22;
const int InB_Left = 21;
const int Spd_Left = 23;

const int InA_Right = 34;
const int InB_Right = 33;
const int Spd_Right = 35;
#pragma endregion Motor Pin Assignments

const int ChgConnectPin = 36;
const int ItotPin = A1;
const int IRunPin = A2;
const int BATT_MON_PIN = A0;

#pragma endregion PIN ASSIGNMENTS

#pragma region MOTOR_PARAMETERS
//drive wheel speed parameters
const int MOTOR_SPEED_FULL = 200; //range is 0-255
const int MOTOR_SPEED_MAX = 255; //range is 0-255
const int MOTOR_SPEED_HALF = 127; //range is 0-255
const int MOTOR_SPEED_QTR = 75; //added 09/25/20
const int MOTOR_SPEED_LOW = 50; //added 01/22/15
const int MOTOR_SPEED_OFF = 0; //range is 0-255
const int MOTOR_SPEED_CAPTURE_OFFSET = 75; //added 06/21/20 for offset capture
const int TURN_START_SPEED = MOTOR_SPEED_QTR; //added 11/14/21

//drive wheel direction constants
const boolean FWD_DIR = true;
const boolean REV_DIR = !FWD_DIR;
const bool TURNDIR_CCW = true;
const bool TURNDIR_CW = false;

//Motor direction variables
bool bIsForwardDir = true; //default is foward direction

#pragma endregion Motor Parameters

#pragma region MPU6050_SUPPORT
uint8_t mpuIntStatus;   // holds actual interrupt status byte from MPU. Used in Homer's Overflow routine
uint8_t devStatus;      // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize;    // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount;     // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer

            // orientation/motion vars
Quaternion q;           // [w, x, y, z]         quaternion container
VectorInt16 aa;         // [x, y, z]            accel sensor measurements
VectorInt16 aaReal;     // [x, y, z]            gravity-free accel sensor measurements
VectorInt16 aaWorld;    // [x, y, z]            world-frame accel sensor measurements
VectorFloat gravity;    // [x, y, z]            gravity vector
float euler[3];         // [psi, theta, phi]    Euler angle container
float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector
int GetPacketLoopCount = 0;
int OuterGetPacketLoopCount = 0;

//MPU6050 status flags
bool bMPU6050Ready = true;
bool dmpReady = false;  // set true if DMP init was successful
volatile float IMUHdgValDeg = 0; //updated by UpdateIMUHdgValDeg()//11/02/20 now updated in ISR
const uint16_t MAX_GETPACKET_LOOPS = 100; //10/30/19 added for backup loop exit condition in GetCurrentFIFOPacket()
uint8_t GetCurrentFIFOPacket(uint8_t* data, uint8_t length, uint16_t max_loops = MAX_GETPACKET_LOOPS); //prototype here so can define a default param
bool bFirstTime = true;
//#define MPU6050_CCW_INCREASES_YAWVAL //added 12/05/19 commented out 11/22/21 as now the MPU6050 module is mounted 'Z-up'
#pragma endregion MPU6050 Support


#pragma region HEADING_AND_RATE_BASED_TURN_PARAMETERS
elapsedMillis MsecSinceLastTurnRateUpdate;

const int MAX_SPIN_MOTOR_SPEED = 250;
const int MIN_SPIN_MOTOR_SPEED = 50;
const int TURN_RATE_UPDATE_INTERVAL_MSEC = 30; //30 mSec is as fast as it can go

double TurnRateOutput;
double TurnRateSetPoint_DPS;
double Ival = 0;
double lastErr = 0;
double lastTurnRateVal_DPS;
double TurnRateVal_DPS;
double Prev_HdgDeg = 0;
float tgt_deg;
float timeout_sec;

//11/16/21 almost perfect for 45 deg/sec, 100mSec
//11/17/21 and pretty good for 90 deg/sec too!
double TurnRate_Kp = 1.8;
double TurnRate_Ki = 1.0;
double TurnRate_Kd = 0.4;

//ported from FourWD_PulseTurnRateTest.ino
double TurnRatePIDOutput;

//06/02/
const float HDG_NEAR_MATCH_VAL = 0.8; //slow the turn down here
const float HDG_FULL_MATCH_VAL = 0.99; //stop the turn here //rev 06/01/21
const float HDG_MIN_MATCH_VAL = 0.6; //added 09/08/18: don't start checking slope until turn is well started
#pragma endregion HEADING_AND_RATE_BASED_TURN_PARAMETERS


#pragma region OTA UPDATE
//******************************************************************************
// hex_info_t	struct for hex record and hex file info
//******************************************************************************
typedef struct {	// 
  char* data;		// pointer to array allocated elsewhere
  unsigned int addr;	// address in intel hex record
  unsigned int code;	// intel hex record type (0=data, etc.)
  unsigned int num;	// number of data bytes in intel hex record

  uint32_t base;	// base address to be added to intel hex 16-bit addr
  uint32_t min;		// min address in hex file
  uint32_t max;		// max address in hex file

  int eof;		// set true on intel hex EOF (code = 1)
  int lines;		// number of hex records received  
} hex_info_t;

void read_ascii_line(Stream* serial, char* line, int maxbytes);
int  parse_hex_line(const char* theline, char* bytes,
  unsigned int* addr, unsigned int* num, unsigned int* code);
int  process_hex_record(hex_info_t* hex);
void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size);

uint32_t buffer_addr, buffer_size; //09/20/21 copied from FlasherX - loop()
#pragma endregion OTA UPDATE
#pragma endregion PRE_SETUP

void setup()
{
  Serial.begin(115200);
  delay(2000); //10/06/21 - just use fixed delay instead

  Serial1.begin(115200); //used HC-05 'AT' commands to set this speed
  //while (!Serial1) {}
  delay(2000); //11/20/21 use fixed delay instead of waiting
  Wire.begin(I2C_MASTER, 0x00, I2C_PINS_18_19, I2C_PULLUP_EXT, 400000);

  //DEBUG!!
  if (Serial)
  {
    Serial.printf("Serial = %p, Serial1 = %p\n", &Serial, &Serial1);
  }
  //DEBUG!!
  // 
  //DEBUG!!
  if (Serial1)
  {
    Serial.printf("Serial = %p, Serial1 = %p\n", &Serial, &Serial1);
  }
  //DEBUG!!


#pragma region PIN INITIALIZATION
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(ItotPin, INPUT); //I_total 1V/Amp
  pinMode(BATT_MON_PIN, INPUT); //Battery voltage monitor

  //motor pins
  pinMode(InA_Left, OUTPUT);
  pinMode(InB_Left, OUTPUT);
  pinMode(Spd_Left, OUTPUT);

  pinMode(InA_Right, OUTPUT);
  pinMode(InB_Right, OUTPUT);
  pinMode(Spd_Right, OUTPUT);
#pragma endregion PIN INITIALIZATION


#pragma region MPU6050
  Serial.printf("\nChecking for MPU6050 IMU at I2C Addr 0x%x\n", MPU6050_I2C_ADDR);
  mpu.initialize();

  // verify connection
  Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));

  float StartSec = 0; //used to time MPU6050 init
  Serial.println(F("Initializing DMP..."));
  devStatus = mpu.dmpInitialize();

  // make sure it worked (returns 0 if successful)
  if (devStatus == 0)
  {
    // turn on the DMP, now that it's ready
    Serial.println(F("Enabling DMP..."));
    mpu.setDMPEnabled(true);

    // set our DMP Ready flag so the main loop() function knows it's okay to use it
    Serial.println(F("DMP ready! Waiting for MPU6050 drift rate to settle..."));
    dmpReady = true;

    // get expected DMP packet size for later comparison
    packetSize = mpu.dmpGetFIFOPacketSize();

    Serial.printf("Just after MPU6050 Init\n");
    Serial.printf("Calibrating...\n");
    mpu.CalibrateGyro(); //using default value of 15
    Serial.printf("Retrieving Calibration Values\n\n");
    mpu.PrintActiveOffsets();

    //loop heading display until stabilized
    Serial.printf("\nMsec\tHdg\n");

    UpdateIMUHdgValDeg();
    Prev_HdgDeg = IMUHdgValDeg;
    delay(100);
    UpdateIMUHdgValDeg();

    Serial.printf("%lu\t%2.3f\t%2.3f\n", millis(), IMUHdgValDeg, Prev_HdgDeg);
    while (abs(IMUHdgValDeg - Prev_HdgDeg) > 0.1f)
    {
      Serial.printf("%lu\t%2.3f\n", millis(), IMUHdgValDeg);
      Prev_HdgDeg = IMUHdgValDeg;
      delay(100);
      UpdateIMUHdgValDeg();
    }

    StartSec = millis() / 1000.f;
    Serial.printf("MPU6050 Ready at %2.2f Sec with delta = %2.3f\n", StartSec, IMUHdgValDeg - Prev_HdgDeg);
    bMPU6050Ready = true;

    delay(1000);
  }
  else //MPU6050 Init failed for some reason
  {
    // ERROR!
    // 1 = initial memory load failed
    // 2 = DMP configuration updates failed
    // (if it's going to break, usually the code will be 1)
    Serial.print(F("DMP Initialization failed (code "));
    Serial.print(devStatus);
    Serial.println(F(")"));

    //08/29/21 print out battery voltage on failure
    float batV = GetBattVoltage();
    Serial.printf("Battery Voltage = %2.2f\n", batV);

    bMPU6050Ready = false;
  }
#pragma endregion MPU6050


  analogReadAveraging(4); //applies to all analogRead() operations?
  MsecSinceLastLEDToggle = 0;

  Serial1.printf("Msec\tBattV\tTotAmps\tRunAmps\tHdgDeg\n");
}

void loop()
{
  //if (Serial1.available())
  if (Serial1.available()||Serial.available())
  {
    CheckForUserInput();
  }

  if (MsecSinceLastLEDToggle >= 200)
  {
    MsecSinceLastLEDToggle -= 200;
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));

    //11/01/21 read I_tot value & cvt to current
    int ItotVal = analogRead(ItotPin);
    double ItotVolts = ItotVal * VoltsPerCount;
    double ItotAmps = ItotVolts * AmpsPerVolt;

    //Get battery voltage
    float calc_volts = GetBattVoltage();

    //print out battery voltage & charge current
    Serial1.printf("%lu\t%2.2f\t%2.2f\n", millis(), calc_volts, ItotAmps);
    Serial.printf("%lu\t%2.2f\t%2.2f\n", millis(), calc_volts, ItotAmps);
  }
}


float GetBattVoltage()
{
  //02/18/17 get corrected battery voltage.  Voltage reading is 1/3 actual Vbatt value
  //int analog_batt_reading = GetAverageAnalogReading(BATT_MON_PIN, VOLTS_AVERAGE_NUMBER);//rev 03/01/19 to average readings
  int analog_batt_reading = analogRead(BATT_MON_PIN);//analogReadAveraging(4) in setup() does internal averaging
  float calc_volts = ZENER_VOLTAGE_OFFSET + ADC_REF_VOLTS * (double)analog_batt_reading / (double)MAX_AD_COUNT;

  ////DEBUG!!
  //	Serial1.printf("a/d = %d, calc = %2.2f\n", analog_batt_reading,calc_volts);
  ////DEBUG!!

  return calc_volts;
}



//void CheckForUserInput()
//{
//  //Notes:
//  //  11/21/21 rev to accomodate cmd input from either serial, and output to both
//
//  const int bufflen = 80;
//  char buff[bufflen];
//  memset(buff, 0, bufflen);
//  float OffsetCm;
//  float Kp, Ki, Kd;
//  const char s[2] = ",";
//  char* token;
//  byte incomingByte = 0; //moved here 11/21/21
//
//  if (Serial.available() > 0)
//  {
//    // read the incoming byte:
//    //int incomingByte = Serial.read();
//    incomingByte = Serial.read();
//
//    // say what you got:
//    Serial.print("I received: ");
//    Serial.println(incomingByte, HEX); //chg to HEX 02/18/20
//  }
//
//  //11/21/21 now input can come from Serial1 too
//  else if (Serial1.available() > 0)
//  {
//    // read the incoming byte:
//    incomingByte = Serial1.read();
//
//    // say what you got:
//    Serial1.print("I received: ");
//    Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20
//  }
//
//  //11/21/21 incomingByte can come from either serial input
//  if (incomingByte != 0)
//  {
//    //02/18/20 experiment with multiple commands
//    switch (incomingByte)
//    {
//    case 0x55: //ASCII 'U'
//    case 0x75: //ASCII 'u'
//#pragma region FIRMWARE UPDATE
//      Serial1.println(F("Start Program Update - Send new HEX file!"));
//
//
//      //09/20/21 copied from FlasherX - loop()
//      if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)
//      {
//        Serial1.printf("unable to create buffer\n");
//        Serial1.flush();
//        for (;;) {}
//      }
//
//      Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",
//        buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",
//        buffer_addr, buffer_addr + buffer_size);
//
//      //09/20/21 clear the serial buffer
//      while (Serial1.available())
//      {
//        Serial1.read();
//      }
//
//      // receive hex file via serial, write new firmware to flash, clean up, reboot
//      update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success
//
//      // return from update_firmware() means error or user abort, so clean up and
//      // reboot to ensure that static vars get boot-up initialized before retry
//      Serial1.printf("erase FLASH buffer / free RAM buffer...\n");
//      firmware_buffer_free(buffer_addr, buffer_size);
//      Serial1.flush();
//      REBOOT;
//      break;
//#pragma endregion FIRMWARE UPDATE
//    case 0x43: //ASCII 'C'
//    case 0x63: //ASCII 'c'
//#pragma region MANUALCONTROL
//      //enter infinite loop for direct remote control
//      Serial.println(F("ENTERING COMMAND MODE:"));
//      Serial.println(F("0 = 180 deg CCW Turn"));
//      Serial.println(F("1 = 180 deg CW Turn"));
//      Serial.println(F("A = Back to Auto Mode"));
//      Serial.println(F("S = Stop"));
//      Serial.println(F("F = Forward"));
//      Serial.println(F("R = Reverse"));
//      Serial.println(F(""));
//      Serial.println(F("       Faster"));
//      Serial.println(F("\t8"));
//      Serial.println(F("Left 4\t5  6 Right"));
//      Serial.println(F("\t2"));
//      Serial.println(F("       Slower"));
//
//      Serial1.println(F("ENTERING COMMAND MODE:"));
//      Serial1.println(F("0 = 180 deg CCW Turn"));
//      Serial1.println(F("1 = 180 deg CW Turn"));
//      Serial1.println(F("A = Back to Auto Mode"));
//      Serial1.println(F("S = Stop"));
//      Serial1.println(F("F = Forward"));
//      Serial1.println(F("R = Reverse"));
//      Serial1.println(F(""));
//      Serial1.println(F("       Faster"));
//      Serial1.println(F("\t8"));
//      Serial1.println(F("Left 4\t5  6 Right"));
//      Serial1.println(F("\t2"));
//      Serial1.println(F("       Slower"));
//
//      StopBothMotors();
//      int speed = 0;
//
//      bool bAutoMode = false;
//      while (!bAutoMode)
//      {
//        if (Serial.available() > 0)
//        {
//          // read the incoming byte:
//          incomingByte = Serial.read();
//
//          // say what you got:
//          Serial.print("I received: ");
//          Serial.println(incomingByte, HEX); //chg to HEX 02/18/20
//        }
//
//        //11/21/21 now input can come from Serial1 too
//        else if (Serial1.available() > 0)
//        {
//          // read the incoming byte:
//          incomingByte = Serial1.read();
//
//          // say what you got:
//          Serial1.print("I received: ");
//          Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20
//        }
//
//        //11/21/21 incomingByte can come from either serial input
//        if (incomingByte != 0)
//        {
//          switch (incomingByte)
//          {
//          case 0x30: //Dec '0'
//            Serial.println(F("CCW 180 deg Turn"));
//            Serial1.println(F("CCW 180 deg Turn"));
//            SpinTurn(true, 180, 90);
//            MoveAhead(speed, speed);
//            break;
//          case 0x31: //Dec '1'
//            Serial.println(F("CW 180 deg Turn"));
//            Serial1.println(F("CW 180 deg Turn"));
//            SpinTurn(false, 180, 45);
//            break;
//          case 0x34: //Turn left 10 deg and keep moving
//            Serial.println(F("CCW 10 deg Turn"));
//            Serial1.println(F("CCW 10 deg Turn"));
//            SpinTurn(true, 10, 30);
//
//            if (bIsForwardDir)
//            {
//              MoveAhead(speed, speed);
//            }
//            else
//            {
//              MoveReverse(speed, speed);
//            }
//            break;
//          case 0x36: //Turn right 10 deg and keep moving
//            Serial.print("CW 10 deg Turn\n");
//            Serial1.print("CW 10 deg Turn\n");
//            SpinTurn(false, 10, 30);
//
//            //added 05/03/20
//            if (bIsForwardDir)
//            {
//              MoveAhead(speed, speed);
//            }
//            else
//            {
//              MoveReverse(speed, speed);
//            }
//            break;
//          case 0x38: //Speed up 
//            speed += 50;
//            speed = (speed >= MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : speed;
//            Serial.printf("Speeding up: speed now %d\n", speed);
//            Serial1.printf("Speeding up: speed now %d\n", speed);
//            if (bIsForwardDir)
//            {
//              MoveAhead(speed, speed);
//            }
//            else
//            {
//              MoveReverse(speed, speed);
//            }
//            break;
//          case 0x32: //Slow down 
//            speed -= 50;
//            speed = (speed < 0) ? 0 : speed;
//            Serial.printf("Slowing down: speed now %d\n", speed);
//            Serial1.printf("Slowing down: speed now %d\n", speed);
//            if (bIsForwardDir)
//            {
//              MoveAhead(speed, speed);
//            }
//            else
//            {
//              MoveReverse(speed, speed);
//            }
//            break;
//          case 0x35: //05/07/20 changed to use '5' vs 'S'
//            Serial.println(F("Stopping Motors!"));
//            Serial1.println(F("Stopping Motors!"));
//            StopBothMotors();
//            speed = 0;
//            break;
//          case 0x41: //ASCII 'A'
//          case 0x61: //ASCII 'a'
//            StopBothMotors();
//            Serial.println(F("Re-entering AUTO mode"));
//            Serial1.println(F("Re-entering AUTO mode"));
//            bAutoMode = true;
//            break;
//          case 0x52: //ASCII 'R'
//          case 0x72: //ASCII 'r'
//            Serial.println(F("Setting both motors to reverse"));
//            Serial1.println(F("Setting both motors to reverse"));
//            bIsForwardDir = false;
//            //MoveReverse(speed, speed);
//            break;
//          case 0x46: //ASCII 'F'
//          case 0x66: //ASCII 'f'
//            Serial.println(F("Setting both motors to forward"));
//            Serial1.println(F("Setting both motors to forward"));
//            bIsForwardDir = true;
//            MoveAhead(speed, speed);
//#pragma endregion MANUALCONTROL
//            break;
//
//#pragma region	WALL OFFSET TRACKING CASES
//            //left side wall tracking
//          case 0x4C: //ASCII 'L'
//          case 0x6C: //ASCII 'l'
//            StopBothMotors();
//            Serial.println(F("Setting Kp value"));
//
//            //consume CR/LF chars
//            while (Serial.available() > 0)
//            {
//              int byte = Serial.read();
//              Serial.printf("consumed %d\n", byte);
//            }
//
//            while (!Serial.available())
//            {
//            }
//
//            Serial.readBytes(buff, bufflen);
//            Serial.printf("%s\n", buff);
//
//            /* extract Kp */
//            token = strtok(buff, s);
//            Kp = atof(token);
//
//            /* extract Ki */
//            token = strtok(NULL, s);
//            Ki = atof(token);
//
//            /* extract Kd */
//            token = strtok(NULL, s);
//            Kd = atof(token);
//
//            /* extract Offset in cm */
//            token = strtok(NULL, s);
//            OffsetCm = atof(token);
//
//            Serial.printf("Kp,Ki,Kd,OffsetCm =  %2.2f, %2.2f, %2.2f, %2.2f\n",
//              Kp, Ki, Kd, OffsetCm);
//
//            //TrackLeftWallOffset(Kp, Ki, Kd, OffsetCm);
//            break;
//          case 0x4D: //ASCII 'M'
//          case 0x6D: //ASCII 'm'
//            StopBothMotors();
//            Serial.println(F("Setting Kp value"));
//
//            //consume CR/LF chars
//            while (Serial.available() > 0)
//            {
//              int byte = Serial.read();
//              Serial.printf("consumed %d\n", byte);
//            }
//
//            while (!Serial.available())
//            {
//            }
//
//            Serial.readBytes(buff, bufflen);
//            Serial.printf("%s\n", buff);
//
//            /* extract Kp */
//            token = strtok(buff, s);
//            Kp = atof(token);
//
//            /* extract Ki */
//            token = strtok(NULL, s);
//            Ki = atof(token);
//
//            /* extract Kd */
//            token = strtok(NULL, s);
//            Kd = atof(token);
//
//            /* extract Offset in cm */
//            token = strtok(NULL, s);
//            OffsetCm = atof(token);
//
//            Serial.printf("Kp,Ki,Kd,OffsetCm =  %2.2f, %2.2f, %2.2f, %2.2f\n",
//              Kp, Ki, Kd, OffsetCm);
//
//            //TrackRightWallOffset(Kp, Ki, Kd, OffsetCm);
//            break;
//#pragma endregion	WALL OFFSET TRACKING CASES
//          default:
//            Serial.println(F("In Default Case: Stopping Motors!"));
//            Serial1.println(F("In Default Case: Stopping Motors!"));
//            StopBothMotors();
//            while (true)
//            {
//
//            }
//          }
//        }
//      }
//    }
//  }
//}


void CheckForUserInput()
{
  //Notes:
  //  11/21/21 rev to accomodate cmd input from either serial, and output to both

  const int bufflen = 3;
  char buff[bufflen];
  memset(buff, 0, bufflen);
  byte incomingByte = 0; //moved here 11/21/21
  int numchars = 0;

  if (Serial.available() > 0)
  {
    // read the incoming byte:
    //incomingByte = Serial.read();
    numchars = Serial.readBytesUntil('\n', buff, sizeof(buff));
    incomingByte = buff[0];

    // say what you got:
    Serial.printf("I received %d chars, first char 0X%X on Serial\n", numchars, incomingByte);
  }

  //11/21/21 now input can come from Serial1 too
  else if (Serial1.available() > 0)
  {
    // read the incoming byte:
    //incomingByte = Serial1.read();
    numchars = Serial1.readBytesUntil('\n', buff, sizeof(buff));
    incomingByte = buff[0];

    // say what you got:
    Serial1.printf("I received %d chars, first char 0X%X on Serial1\n", numchars, incomingByte);
  }

  //11/21/21 incomingByte can come from either serial input
  if (incomingByte != 0)
  {
    //02/18/20 experiment with multiple commands
    switch (incomingByte)
    {
    case 0x55: //ASCII 'U'
    case 0x75: //ASCII 'u'
#pragma region FIRMWARE UPDATE
      Serial1.println(F("Start Program Update - Send new HEX file!"));


      //09/20/21 copied from FlasherX - loop()
      if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)
      {
        Serial1.printf("unable to create buffer\n");
        Serial1.flush();
        for (;;) {}
      }

      Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",
        buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",
        buffer_addr, buffer_addr + buffer_size);

      //09/20/21 clear the serial buffer
      while (Serial1.available())
      {
        Serial1.read();
      }

      // receive hex file via serial, write new firmware to flash, clean up, reboot
      update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success

      // return from update_firmware() means error or user abort, so clean up and
      // reboot to ensure that static vars get boot-up initialized before retry
      Serial1.printf("erase FLASH buffer / free RAM buffer...\n");
      firmware_buffer_free(buffer_addr, buffer_size);
      Serial1.flush();
      REBOOT;
      break;
#pragma endregion FIRMWARE UPDATE
    case 0x43: //ASCII 'C'
    case 0x63: //ASCII 'c'
#pragma region MANUALCONTROL
      //enter infinite loop for direct remote control
      Serial.println(F("ENTERING COMMAND MODE:"));
      Serial.println(F("0 = 180 deg CCW Turn"));
      Serial.println(F("1 = 180 deg CW Turn"));
      Serial.println(F("A = Back to Auto Mode"));
      Serial.println(F("S = Stop"));
      Serial.println(F("F = Forward"));
      Serial.println(F("R = Reverse"));
      Serial.println(F(""));
      Serial.println(F("       Faster"));
      Serial.println(F("\t8"));
      Serial.println(F("Left 4\t5  6 Right"));
      Serial.println(F("\t2"));
      Serial.println(F("       Slower"));

      Serial1.println(F("ENTERING COMMAND MODE:"));
      Serial1.println(F("0 = 180 deg CCW Turn"));
      Serial1.println(F("1 = 180 deg CW Turn"));
      Serial1.println(F("A = Back to Auto Mode"));
      Serial1.println(F("S = Stop"));
      Serial1.println(F("F = Forward"));
      Serial1.println(F("R = Reverse"));
      Serial1.println(F(""));
      Serial1.println(F("       Faster"));
      Serial1.println(F("\t8"));
      Serial1.println(F("Left 4\t5  6 Right"));
      Serial1.println(F("\t2"));
      Serial1.println(F("       Slower"));

      StopBothMotors();
      int speed = 0;
      bool bAutoMode = false;
      while (Serial.available())
      {
        incomingByte = Serial.read();
        //Serial.printf("I removed 0X%X from Serial\n",incomingByte);
      }
      while (Serial1.available())
      {
        incomingByte = Serial1.read();
        //Serial1.printf("I removed 0X%X from Serial1\n", incomingByte);
      }

      incomingByte = 0;

      while (!bAutoMode)
      {
        if (Serial.available() > 0)
        {
          // read the incoming bytes:
          numchars = Serial.readBytesUntil('\n', buff, sizeof(buff));
          incomingByte = buff[0];

          // say what you got:
          Serial.printf("I received %d chars, first char 0X%X on Serial\n", numchars, incomingByte);

          while (Serial.available())
          {
            Serial.read();
            Serial.printf("I removed 0X%X from Serial\n",incomingByte);
          }
        }

        //11/21/21 now input can come from Serial1 too
        else if (Serial1.available() > 0)
        {
          // read the incoming bytes:
          numchars = Serial1.readBytesUntil('\n', buff, sizeof(buff));
          incomingByte = buff[0];

          // say what you got:
          Serial1.printf("I received %d chars, first char 0X%X on Serial1\n", numchars, incomingByte);

          while (Serial1.available())
          {
            Serial1.read();
            Serial1.printf("I removed 0X%X from Serial1\n", incomingByte);
          }
        }


        //11/21/21 incomingByte can come from either serial input
        if (incomingByte != 0)
        {
          switch (incomingByte)
          {
          case 0x30: //Dec '0'
            Serial.println(F("CCW 180 deg Turn"));
            Serial1.println(F("CCW 180 deg Turn"));
            SpinTurn(true, 180, 90);
            MoveAhead(speed, speed);
            break;
          case 0x31: //Dec '1'
            Serial.println(F("CW 180 deg Turn"));
            Serial1.println(F("CW 180 deg Turn"));
            SpinTurn(false, 180, 45);
            break;
          case 0x34: //Turn left 10 deg and keep moving
            Serial.println(F("CCW 10 deg Turn"));
            Serial1.println(F("CCW 10 deg Turn"));
            SpinTurn(true, 10, 30);

            if (bIsForwardDir)
            {
              MoveAhead(speed, speed);
            }
            else
            {
              MoveReverse(speed, speed);
            }
            break;
          case 0x36: //Turn right 10 deg and keep moving
            Serial.print("CW 10 deg Turn\n");
            Serial1.print("CW 10 deg Turn\n");
            SpinTurn(false, 10, 30);

            //added 05/03/20
            if (bIsForwardDir)
            {
              MoveAhead(speed, speed);
            }
            else
            {
              MoveReverse(speed, speed);
            }
            break;
          case 0x38: //Speed up 
            speed += 50;
            speed = (speed >= MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : speed;
            Serial.printf("Speeding up: speed now %d\n", speed);
            Serial1.printf("Speeding up: speed now %d\n", speed);
            if (bIsForwardDir)
            {
              MoveAhead(speed, speed);
            }
            else
            {
              MoveReverse(speed, speed);
            }
            break;
          case 0x32: //Slow down 
            speed -= 50;
            speed = (speed < 0) ? 0 : speed;
            Serial.printf("Slowing down: speed now %d\n", speed);
            Serial1.printf("Slowing down: speed now %d\n", speed);
            if (bIsForwardDir)
            {
              MoveAhead(speed, speed);
            }
            else
            {
              MoveReverse(speed, speed);
            }
            break;
          case 0x35: //05/07/20 changed to use '5' vs 'S'
            Serial.println(F("Stopping Motors!"));
            Serial1.println(F("Stopping Motors!"));
            StopBothMotors();
            speed = 0;
            break;
          case 0x41: //ASCII 'A'
          case 0x61: //ASCII 'a'
            StopBothMotors();
            Serial.println(F("Re-entering AUTO mode"));
            Serial1.println(F("Re-entering AUTO mode"));
            bAutoMode = true;
            break;
          case 0x52: //ASCII 'R'
          case 0x72: //ASCII 'r'
            Serial.println(F("Setting both motors to reverse"));
            Serial1.println(F("Setting both motors to reverse"));
            bIsForwardDir = false;
            //MoveReverse(speed, speed);
            break;
          case 0x46: //ASCII 'F'
          case 0x66: //ASCII 'f'
            Serial.println(F("Setting both motors to forward"));
            Serial1.println(F("Setting both motors to forward"));
            bIsForwardDir = true;
            MoveAhead(speed, speed);
#pragma endregion MANUALCONTROL
            break;
          default:
            Serial.println(F("In Default Case: Stopping Motors!"));
            Serial1.println(F("In Default Case: Stopping Motors!"));
            StopBothMotors();
            //while (true)
            //{

            //}
          }
          incomingByte = 0;
        }
      }
    }
  }
}


#pragma region MOTOR SUPPORT
//09/08/20 modified for DRV8871 motor driver
void MoveReverse(int leftspeednum, int rightspeednum)
{
  //Purpose:  Move in reverse direction continuously - companion to MoveAhead()
  //ProvEnA_Pinnce: G. Frank Paynter 09/08/18
  //Inputs:  
  //    leftspeednum = integer denoting speed (0=stop, 255 = full speed)
  //    rightspeednum = integer denoting speed (0=stop, 255 = full speed)
  //Outputs: both drive Motors energized with the specified speed
  //Plan:
  //    Step 1: Set reverse direction for both wheels
  //    Step 2: Run both Motors at specified speeds
  //Notes:
  //	01/22/20 now using Adafruit DRV8871 drivers

  //Step 1: Set reverse direction and speed for both wheels
  SetLeftMotorDirAndSpeed(REV_DIR, leftspeednum);
  SetRightMotorDirAndSpeed(REV_DIR, rightspeednum);
}

//09/08/20 modified for DRV8871 motor driver
void MoveAhead(int leftspeednum, int rightspeednum)
{
  //Purpose:  Move ahead continuously
  //ProvEnA_Pinnce: G. Frank Paynter and Danny Frank 01/24/2014
  //Inputs:  
  //    leftspeednum = integer denoting speed (0=stop, 255 = full speed)
  //    rightspeednum = integer denoting speed (0=stop, 255 = full speed)
  //Outputs: both drive Motors energized with the specified speed
  //Plan:
  //    Step 1: Set forward direction for both wheels
  //    Step 2: Run both Motors at specified speeds
  //Notes:
  //	01/22/20 now using Adafruit DRV8871 drivers

  //Serial1.printf("InMoveAhead(%d,%d)\n", leftspeednum, rightspeednum);

  //Step 1: Set forward direction and speed for both wheels
  SetLeftMotorDirAndSpeed(true, leftspeednum);
  SetRightMotorDirAndSpeed(true, rightspeednum);
}

//09/08/20 modified for DRV8871 motor driver
//11/04/21 modified for Pololu VNH5019 motor driver
void StopLeftMotors()
{
  digitalWrite(InA_Left, LOW);
  digitalWrite(InB_Left, LOW);
  analogWrite(Spd_Left, MOTOR_SPEED_OFF);
}

//11/04/21 modified for Pololu VNH5019 motor driver
void StopRightMotors()
{
  digitalWrite(InA_Right, LOW);
  digitalWrite(InB_Right, LOW);
  analogWrite(Spd_Right, MOTOR_SPEED_OFF);
}

//09/08/20 added bool bisFwd param for DRV8871 motor driver
void RunBothMotors(bool bisFwd, int leftspeednum, int rightspeednum)
{
  //Purpose: Run both Motors at left/rightspeednum speeds
  //Inputs:
  //    speednum = speed value (0 = OFF, 255 = full speed)
  //Outputs: Both Motors run for timesec seconds at speednum speed
  //Plan:
  //    Step 1: Apply drive to both wheels
  //Notes:
  //    01/14/15 - added left/right speed offset for straightness compensation
  //    01/22/15 - added code to restrict fast/slow values
  //    01/24/15 - revised for continuous run - no timing
  //  01/26/15 - speednum modifications moved to UpdateWallFollowmyMotorspeeds()
  //	12/07/15 - chg args from &int to int
  //Step 1: Apply drive to both wheels

//DEBUG!!
  //Serial1.printf("In RunBothMotors(%s, %d,%d)\n", bisFwd? "FWD":"REV", leftspeednum, rightspeednum);
//DEBUG!!

  SetLeftMotorDirAndSpeed(bisFwd, leftspeednum);
  SetRightMotorDirAndSpeed(bisFwd, rightspeednum);
}

void RunBothMotorsBidirectional(int leftspeed, int rightspeed)
{
  //Purpose:  Accommodate the need for independent bidirectional wheel motion
  //Inputs:
  //	leftspeed - integer denoting left wheel speed.  Positive value is fwd, negative is rev
  //	rightspeed - integer denoting right wheel speed.  Positive value is fwd, negative is rev
  //Outputs:
  //	left/right wheel motors direction and speed set as appropriate
  //Plan:
  //	Step1: Set left wheel direction and speed
  //	Step2: Set right wheel direction and speed

//Step1: Set left wheel direction and speed

  //DEBUG!!
  //Serial1.printf("In RunBothMotorsBidirectional(%d, %d)\n", leftspeed, rightspeed);
  if (leftspeed < 0)
  {
    SetLeftMotorDirAndSpeed(false, -leftspeed); //neg value ==> reverse
  }
  else
  {
    SetLeftMotorDirAndSpeed(true, leftspeed); //pos or zero value ==> fwd
  }

  //Step2: Set right wheel direction and speed
  if (rightspeed < 0)
  {
    SetRightMotorDirAndSpeed(false, -rightspeed); //neg value ==> reverse
  }
  else
  {
    SetRightMotorDirAndSpeed(true, rightspeed); //pos or zero value ==> fwd
  }
}

//09/08/20 added bool bisFwd param for DRV8871 motor driver
void RunBothMotorsMsec(bool bisFwd, int timeMsec, int leftspeednum, int rightspeednum)
{
  //Purpose: Run both Motors for timesec seconds at speednum speed
  //Inputs:
  //    timesec = time in seconds to run the Motors
  //    speednum = speed value (0 = OFF, 255 = full speed)
  //Outputs: Both Motors run for timesec seconds at speednum speed
  //Plan:
  //    Step 1: Apply drive to both wheels
  //    Step 2: Delay timsec seconds
  //    Step 3: Remove drive from both wheels.
  //Notes:
  //    01/14/15 - added left/right speed offset for straightness compensation
  //    01/22/15 - added code to restrict fast/slow values
  //	11/25/15 - rev to use motor driver class object
  //	09/08/20 added bool bisFwd param for DRV8871 motor driver

  RunBothMotors(bisFwd, leftspeednum, rightspeednum);

  //Step 2: Delay timsec seconds
  delay(timeMsec);

  //Step3: Stop motors added 04/12/21
  StopBothMotors();
}

//11/25/15 added for symmetry ;-).
void StopBothMotors()
{
  StopLeftMotors();
  StopRightMotors();
}

void SetLeftMotorDirAndSpeed(bool bIsFwd, int speed)
{
//DEBUG!!
  //Serial.printf("In SetLeftMotorDirAndSpeed(%s, %d)\n",
  //  (bIsFwd == true) ? "true" : "false", speed);
  //Serial1.printf("In SetLeftMotorDirAndSpeed(%s, %d)\n",
  //  (bIsFwd == true) ? "true" : "false", speed);
//DEBUG!!

  //11/04/21 fwd for right motors is CCW when looking at shaft
#ifndef NO_MOTORS
  if (bIsFwd)
  {
    digitalWrite(InA_Left, LOW);
    digitalWrite(InB_Left, HIGH);
    analogWrite(Spd_Left, speed);

//DEBUG!!
    //Serial.printf("In TRUE block of SetLeftMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
    //Serial1.printf("In TRUE block of SetLeftMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
//DEBUG!!
  }
  else
  {
//DEBUG!!
    //Serial.printf("In FALSE block of SetLeftMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
    //Serial1.printf("In FALSE block of SetLeftMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
//DEBUG!!

    digitalWrite(InA_Left, HIGH);
    digitalWrite(InB_Left, LOW);
    analogWrite(Spd_Left, speed);
  }
#endif // !NO_MOTORS
}

void SetRightMotorDirAndSpeed(bool bIsFwd, int speed)
{
//DEBUG!!
  //Serial.printf("In SetRightMotorDirAndSpeed(%s, %d)\n",
  //  (bIsFwd == true) ? "true" : "false", speed);
  //Serial1.printf("In SetRightMotorDirAndSpeed(%s, %d)\n",
  //  (bIsFwd == true) ? "true" : "false", speed);
//DEBUG!!

  //11/04/21 fwd for right motors is CW when looking at shaft
#ifndef NO_MOTORS

  if (bIsFwd)
  {
//DEBUG!!
    //Serial.printf("In TRUE block of SetRighttMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
    //Serial1.printf("In TRUE block of SetRighttMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
//DEBUG!!

    digitalWrite(InA_Right, HIGH);
    digitalWrite(InB_Right, LOW);
    analogWrite(Spd_Right, speed);
  }
  else
  {
//DEBUG!!
    //Serial.printf("In FALSE block of SetRightMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
    //Serial1.printf("In FALSE block of SetRightMotorDirAndSpeed(%s, %d)\n",
    //  (bIsFwd == true) ? "true" : "false", speed);
    //DEBUG!!

    digitalWrite(InA_Right, LOW);
    digitalWrite(InB_Right, HIGH);
    analogWrite(Spd_Right, speed);
  }

#endif // !NO_MOTORS
}
#pragma endregion Motor Support Functions

#pragma region HDG_BASED_TURN_SUPPORT

bool SpinTurn(bool b_ccw, float numDeg, float degPersec) //04/25/21 added turn-rate arg (default = TURN_RATE_TARGET_DEGPERSEC)
{
  //Purpose: Make a numDeg CW or CCW 'spin' turn
  //Inputs:
  //	b_ccw - True if turn is to be ccw, false otherwise
  //	numDeg - angle to be swept out in the turn
  //	ROLLING_TURN_MAX_SEC_PER_DEG = const used to generate timeout proportional to turn deg
  //	IMUHdgValDeg = IMU heading value updated by UpdateIMUHdgValDeg() //11/02/20 now updated in ISR
  //	degPerSec = float value denoting desired turn rate
  //Plan:
  //	Step1: Get current heading as starting point
  //	Step2: Disable TIMER5 interrupts
  //	Step3: Compute new target value & timeout value
  //	Step4: Run motors until target reached, using inline PID algorithm to control turn rate
  //	Step5: Re-enable TIMER5 interrupts
  //Notes:
  //	06/06/21 we-written to remove PID library - now uses custom 'PIDCalcs()' function
  //	06/06/21 added re-try for 180.00 return from IMU - could be bad value
  //	06/11/21 added code to correct dHdg errors due to 179/-179 transition & bad IMU values
  //	06/12/21 cleaned up & commented out debug code
  //	11/14/21 removed 'first time skip' block; added motor start before entering loop

  float tgt_deg;
  float timeout_sec;
  bool bDoneTurning = false;
  bool bTimedOut = false;
  bool bResult = true; //04/21/20 added so will be only one exit point

  //DEBUG!!
  Serial.printf("In SpinTurn(%s, %2.2f, %2.2f)\n", b_ccw == TURNDIR_CCW ? "CCW" : "CW", numDeg, degPersec);
  Serial1.printf("In SpinTurn(%s, %2.2f, %2.2f)\n", b_ccw == TURNDIR_CCW ? "CCW" : "CW", numDeg, degPersec);
  //Serial.printf("TurnRatePID started with Kp/Ki/Kd = %2.1f,%2.1f,%2.1f, SampleTime(mSec) = %d\n",
    //TurnRate_Kp, TurnRate_Ki, TurnRate_Kd, TURN_RATE_UPDATE_INTERVAL_MSEC);
  //DEBUG!!

  //no need to continue if the IMU isn't available
  if (!dmpReady)
  {
    Serial.printf("DMP Failure - returning FALSE\n");
    return false;
  }

  //Step1: Get current heading as starting point
    //06/06/21 it is possible for IMU to return 180.00 on failure
    //so try again.  If it really IS 180, then 
    //it will eventually time out and go on

  //08/26/21 re-wrote using 3-value array to make sure initial heading is a steady value
  UpdateIMUHdgValDeg();

  int retries = 0;
  if ((IMUHdgValDeg == 180.f || IMUHdgValDeg == 0.f) && retries < 5)
  {
    //DEBUG!!
    Serial.printf("Got 180.00 or 0.00 exactly (%2.3f) from IMU - retrying %d...\n", IMUHdgValDeg, retries);
    Serial1.printf("Got 180.00 or 0.00 exactly (%2.3f) from IMU - retrying %d...\n", IMUHdgValDeg, retries);
    //DEBUG!!
    UpdateIMUHdgValDeg();
    retries++;
    delay(100);
  }

  //Step2: Compute new target value & timeout value
  //timeout_sec = 3 * numDeg / degPersec; //05/29/21 rev to use new turn rate parmeter
  timeout_sec = 2 * numDeg / degPersec; //05/29/21 rev to use new turn rate parmeter

  //05/17/20 limit timeout_sec to 1 sec or more
  timeout_sec = (timeout_sec < 1) ? 1.f : timeout_sec;

  //12/05/19 added #define back in to manage which direction increases yaw values
#ifdef MPU6050_CCW_INCREASES_YAWVAL
  tgt_deg = b_ccw ? IMUHdgValDeg + numDeg : IMUHdgValDeg - numDeg;
#else
  tgt_deg = b_ccw ? IMUHdgValDeg - numDeg : IMUHdgValDeg + numDeg;

#endif // MPU6050_CCW_INCREASES_YAWVAL

  //correct for -180/180 transition
  if (tgt_deg < -180)
  {
    tgt_deg += 360;
  }

  //07/29/19 bugfix
  if (tgt_deg > 180)
  {
    tgt_deg -= 360;
  }

  //DEBUG!!
  Serial.printf("Init hdg = %4.2f deg, Turn = %4.2f  deg, tgt = %4.2f deg, timeout = %4.2f sec\n\n",
    IMUHdgValDeg, numDeg, tgt_deg, timeout_sec);
  Serial1.printf("Init hdg = %4.2f deg, Turn = %4.2f  deg, tgt = %4.2f deg, timeout = %4.2f sec\n\n",
    IMUHdgValDeg, numDeg, tgt_deg, timeout_sec);
  //DEBUG!!

  float curHdgMatchVal = 0;

  //09/08/18 added to bolster end-of-turn detection
  float prevHdgMatchVal = 0;
  float matchSlope = 0;

  //Step3: Run motors until target reached, using PID algorithm to control turn rate
  Prev_HdgDeg = IMUHdgValDeg; //06/10/21 synch Prev_HdgDeg & IMUHdgValDeg just before entering loop

  //11/14/21 start motors before entering loop.  For CCW turn, left motors go backwards, right ones forward
  int startSpd = (degPersec <= 45) ? TURN_START_SPEED : 2 * TURN_START_SPEED;
  SetLeftMotorDirAndSpeed(!b_ccw, startSpd);
  SetRightMotorDirAndSpeed(b_ccw, startSpd);



  elapsedMillis sinceLastTimeCheck = 0;
  elapsedMillis sinceLastComputeTime = 0;
  double lastError = 0;
  double lastInput = 0;
  double lastIval = 0;
  double lastDerror = 0;
  //bool bFirstIMUHdg = true;

  //DEBUG!!
  Serial.printf("Msec\tHdg\tPrvHdg\tdHdg\tRate\ttgtDPS\terr\tKp*err\tIval\tKd*Derr\tspeed\tMatch\tSlope\n");
  Serial1.printf("Msec\tHdg\tPrvHdg\tdHdg\tRate\ttgtDPS\terr\tKp*err\tIval\tKd*Derr\tspeed\tMatch\tSlope\n");
  //DEBUG!!

  while (!bDoneTurning && !bTimedOut)
  {
    //11/06/20 now just loops between PID calcs
    CheckForUserInput();

    if (sinceLastComputeTime >= TURN_RATE_UPDATE_INTERVAL_MSEC)
    {
      sinceLastComputeTime -= TURN_RATE_UPDATE_INTERVAL_MSEC;

      UpdateIMUHdgValDeg(); //update IMUHdgValDeg

      double dHdg = IMUHdgValDeg - Prev_HdgDeg;
      if (dHdg > 180)
      {
        dHdg -= 360;
        //Serial.printf("dHdg > 180 - subtracting 360\n");
      }
      else if (dHdg < -180)
      {
        dHdg += 360;
        //Serial.printf("dHdg < -180 - adding 360\n");
      }

      //watch for turn rates that are wildly off
      double rate = abs(1000 * dHdg / TURN_RATE_UPDATE_INTERVAL_MSEC);
      //if (rate > 3 * degPersec)
      //{
      //	//DEBUG!!
      //	Serial.printf("hdg/prevhdg/dHdg/rate = %2.2f\t%2.2f\t%2.2f\t%2.2f, excessive rate - replacing with %2.2f\n", IMUHdgValDeg, Prev_HdgDeg, dHdg, rate, degPersec);
      //	//DEBUG!!
      //	rate = degPersec;
      //}

      TurnRatePIDOutput = PIDCalcs(rate, degPersec, TURN_RATE_UPDATE_INTERVAL_MSEC, lastError, lastInput, lastIval, lastDerror, TurnRate_Kp, TurnRate_Ki, TurnRate_Kd);

      int speed = 0;

      (TurnRatePIDOutput > MOTOR_SPEED_MAX) ? speed = MOTOR_SPEED_MAX : speed = (int)TurnRatePIDOutput;
      (TurnRatePIDOutput <= MOTOR_SPEED_LOW) ? speed = MOTOR_SPEED_LOW : speed = (int)TurnRatePIDOutput;

      SetLeftMotorDirAndSpeed(!b_ccw, speed);
      SetRightMotorDirAndSpeed(b_ccw, speed);

      //check for nearly there and all the way there
      curHdgMatchVal = GetHdgMatchVal(tgt_deg, IMUHdgValDeg);
      matchSlope = curHdgMatchVal - prevHdgMatchVal;

      Serial.printf("%lu\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%d\t%2.2f\t%2.2f\n",
        millis(),
        IMUHdgValDeg,
        Prev_HdgDeg,
        dHdg,
        rate,
        degPersec,
        lastError,
        TurnRate_Kp * lastError,
        lastIval,
        TurnRate_Kd * lastDerror,
        speed,
        curHdgMatchVal,
        matchSlope);

      Serial1.printf("%lu\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%d\t%2.2f\t%2.2f\n",
        millis(),
        IMUHdgValDeg,
        Prev_HdgDeg,
        dHdg,
        rate,
        degPersec,
        lastError,
        TurnRate_Kp * lastError,
        lastIval,
        TurnRate_Kd * lastDerror,
        speed,
        curHdgMatchVal,
        matchSlope);
      //DEBUG!!

      Prev_HdgDeg = IMUHdgValDeg; //re-synch prev to curr hdg for next time

      //look for full match
      bDoneTurning = (curHdgMatchVal >= HDG_FULL_MATCH_VAL
        || (prevHdgMatchVal >= HDG_MIN_MATCH_VAL && matchSlope <= -0.01)); //have to use < vs <= as slope == 0 at start

      //Serial.printf("curHdgMatchVal = %2.2f, prevHdgMatchVal = %2.2f, matchslope = %2.2f, bDoneTurning = %d\n",
      //	curHdgMatchVal,
      //	prevHdgMatchVal,
      //	matchSlope,
      //	bDoneTurning);

      prevHdgMatchVal = curHdgMatchVal; //07/31/21 moved below bDoneTurning chk so can use prevHdgMatchVal vs curHdgMatchVal in slope check

      bTimedOut = (sinceLastTimeCheck > timeout_sec * 1000);

      if (bTimedOut)
      {
        //DEBUG!!
        Serial.printf("timed out with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);
        Serial1.printf("timed out with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);
        //DEBUG!!

        bResult = false;
        break;
      }

      if (bDoneTurning)
      {
        Serial.printf("Completed turn with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);
        Serial1.printf("Completed turn with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);

        bResult = true;
        break;
      }
    }
  }

  StopBothMotors();
  delay(1000); //added 04/27/21 for debug
  return bResult;
}

double PIDCalcs(double input, double setpoint, uint16_t sampleTime, double& lastError, double& lastInput, double& lastIval, double& lastDerror, double Kp, double Ki, double Kd)
{
  //Purpose:  Encapsulate PID algorithm so can get rid of PID library. Library too cumbersome and won't synch with TIMER5 ISR
  //Inputs:
  //	input = double denoting current input value (turn rate, speed, whatever)
  //	setpoint = double denoting desired setpoint in same units as input
  //	sampleTime = int denoting sample time to be used in calcs.
  //	lastError = ref to double denoting error saved from prev calc
  //	lastInput = ref to double denoting input saved from prev calc
  //	Kp/Ki/Kd = doubles denoting PID values to be used for calcs
  //	Output = ref to double denoting output from calc

  double error = setpoint - input;
  //double dInput = (input - lastInput);
  //lastIval += (error);
  lastIval += (Ki * error);

  //11/16/21 rev to clamp integral term
  lastIval = (lastIval > MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : lastIval;
  lastIval = (lastIval < MOTOR_SPEED_OFF) ? MOTOR_SPEED_OFF : lastIval;
  double dErr = (error - lastError);

  //Serial.printf("PIDCalcs: error/dInput/lastIval/dErr/kp/ki/kd = %2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\n", error, dInput, lastIval, dErr,
  //	Kp,Ki,Kd);

  /*Compute PID Output*/
  //11/16/21 rev to subtract differential term rather than add.
  //double output = Kp * error + Ki * lastIval + Kd * dErr;
  double output = Kp * error + lastIval - Kd * dErr;

  //11/16/21 now clamping output value as well as I term
  output = (output > MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : output;
  output = (output < MOTOR_SPEED_OFF) ? MOTOR_SPEED_OFF : output;

  /*Remember some variables for next time*/
  lastError = error;
  lastInput = input;
  lastDerror = dErr;

  return output; //added 09/03/21
}

float GetHdgMatchVal(float tgt_deg, float cur_deg)
{
  //Purpose:  Compute the match ratio between two compass headings
  //Inputs:
  //	tgt_deg = float representing target heading in +/-180 range
  //	IMUHdgValDeg = float representing sensor yaw value in +/-180 deg range
  //Outputs:
  //	returns result of 1 - abs(Tgt_deg - Hdg_deg)/180, all angles in 0-360 deg range
  //Plan:
  //	Step1: convert both inputs to 0-360 deg range
  //	Step2: compute match ratio
  //Notes:
  //	formula from https://gis.stackexchange.com/questions/129954/comparing-compass-bearings

//Step1: convert both inputs to 0-360 deg range
  float tgthdg = (tgt_deg < 0) ? tgt_deg + 360 : tgt_deg;
  float curhdg = (cur_deg < 0) ? cur_deg + 360 : cur_deg;

  //Step2: compute match ratio
  float match_ratio = 1 - abs(tgthdg - curhdg) / 180;

  //DEBUG!!
    //Serial1.printf("tgt\tcur\tmatch = %4.2f\t%4.2f\t%1.3f\n", tgthdg, curhdg, match_ratio);
  //DEBUG!!
  return abs(match_ratio);
}

float UpdateIMUHdgValDeg()
{
  //Purpose: Get latest yaw (heading) value from IMU
  //Inputs: None.  This function should only be called after mpu.dmpPacketAvailable() returns TRUE
  //Outputs: 
  //	returns true if successful, otherwise false
  //	IMUHdgValDeg updated on success
  //Plan:
  //Step1: check for overflow and reset the FIFO if it occurs. In this case, wait for new packet
  //Step2: read all available packets to get to latest data
  //Step3: update IMUHdgValDeg with latest value
  //Notes:
  //	10/08/19 changed return type to boolean
  //	10/08/19 no longer need mpuIntStatus
  //	10/21/19 completely rewritten to use Homer's algorithm
  //	05/05/20 changed return type to float vs bool.

  int flag = GetCurrentFIFOPacket(fifoBuffer, packetSize, MAX_GETPACKET_LOOPS); //get the latest mpu packet

  if (flag != 0) //0 = error exit, 1 = normal exit, 2 = recovered from an overflow
  {
    // display Euler angles in degrees
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    mpu.dmpGetGravity(&gravity, &q);
    mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);

    //compute the yaw value
    IMUHdgValDeg = ypr[0] * 180 / M_PI;
  }

  return IMUHdgValDeg;//05/05/20 now returns updated value for use convenience
}

uint8_t GetCurrentFIFOPacket(uint8_t* data, uint8_t length, uint16_t max_loops)
{
  mpu.resetFIFO();
  delay(1);
  //int countloop = 0;

  fifoCount = mpu.getFIFOCount();
  GetPacketLoopCount = 0;

  //Serial1.printf("In GetCurrentFIFOPacket: before loop fifoC = %d\t", fifoCount);
  while (fifoCount < packetSize && GetPacketLoopCount < max_loops)
  {
    GetPacketLoopCount++;
    fifoCount = mpu.getFIFOCount();
    delay(2);
  }

  //Serial1.printf("In GetCurrentFIFOPacket: after loop fifoC = %d, loop count = %d\n", fifoCount, GetPacketLoopCount);

  if (GetPacketLoopCount >= max_loops)
  {
    return 0;
  }

  //if we get to here, there should be exactly one packet in the FIFO
  mpu.getFIFOBytes(data, packetSize);
  return 1;
}

//void BackupAndTurn90Deg(bool b_ccw, bool b_fwd, int motor_speed)
//{
//  //Purpose: Backup 1 second and then turn 90 degrees
//  //Provenance: G. Frank Paynter 06/27/2020
//  //Inputs:
//  //	bIsCCW = bool denoting direction for the turn
//  //	bIsFwd = bool denoting fwd/bkwd direction for the turn
//  //	motor_speed = int denoting motor speed to use for the maneuver
//  //Outputs:
//  //	Robot backs up 1 sec, then turns 90 deg in the specified direction
//  //Plan:
//  //	Step1: Back up for 1 sec
//  //	Step2: Turn 90 deg in specified direction
//  //Notes:
//  //	06/27/20 Replaces BackupAndTurn in all Tracking modes
//  //10/13/20 rev to terminate backup at Wall Offset Distance
//
////Step1: Back up for 1 sec
//  BackupSignal(true);	//turn backup LEDs ON
//  MoveReverse(MOTOR_SPEED_HALF, MOTOR_SPEED_HALF);
//  //delay(1000);
//
//  //10/13/20 rev to terminate backup at Wall Offset Distance
//  while (frontdistval < WALL_OFFSET_TGTDIST_CM && !bIsStuck)
//  {
//    if (bTimeForNavUpdate) //wait for next ISR hit
//    {
//      bTimeForNavUpdate = false;
//      Serial.print(F("BackupAndTurn90Deg: ")); Serial1.printf("%lu\t% d\n", millis(), frontdistval);
//    }
//  }
//  BackupSignal(false);//turn them back OFF
//
//  //Serial1.printf("BackupAndTurn90Deg terminated with frontdist = %d\n", frontdistval);
//  Serial.print(F("BackupAndTurn90Deg terminated with frontdist = ")); Serial1.printf("%d\n", frontdistval);
//
//  //Step2: Turn 90 deg fwd or backward in specified direction
//  SpinTurn(b_ccw, 90); //06/27/20 experiment
//}
#pragma endregion HDG_BASED_TURN_SUPPORT





#pragma region FLASHER_X

//09/20/21 copied from FlasherX
//******************************************************************************
// update_firmware()	read hex file and write new firmware to program flash
//******************************************************************************
void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size)
{
  static char line[96];					// buffer for hex lines
  static char data[32] __attribute__((aligned(8)));	// buffer for hex data
  hex_info_t hex = {					// intel hex info struct
    data, 0, 0, 0,					//   data,addr,num,code
    0, 0xFFFFFFFF, 0, 					//   base,min,max,
    0, 0						//   eof,lines
  };

  serial->printf("waiting for hex lines...\n");

  // read and process intel hex lines until EOF or error
//DEBUG!!
  //int line_num = 0;
//DEBUG!!
  long int start_msec = 0;
  bool bFirstTime = true;
  while (!hex.eof) {

    read_ascii_line(serial, line, sizeof(line));

    if (bFirstTime)
    {
      start_msec = millis();
      bFirstTime = false;
    }

    //DEBUG!!
        //serial->printf("%d: %s\n", line_num, line);
        //line_num++;
    //DEBUG!!

        //10/02/21 gfp added for visual xfer confirmation
    if (hex.lines % 10 == 0)
    {
      digitalWriteFast(LED_BUILTIN, !digitalReadFast(LED_BUILTIN));
    }

    // reliability of transfer via USB is improved by this printf/flush
    if (serial == (Stream*)&Serial)
    {
      serial->printf("%s\n", line);
      serial->flush();
    }

    if (parse_hex_line((const char*)line, hex.data, &hex.addr, &hex.num, &hex.code) == 0) {
      serial->printf("abort - bad hex line %s\n", line);
      return;
    }
    else if (process_hex_record(&hex) != 0) { // error on bad hex code
      serial->printf("abort - invalid hex code %d\n", hex.code);
      return;
    }
    else if (hex.code == 0) { // if data record
      uint32_t addr = buffer_addr + hex.base + hex.addr - FLASH_BASE_ADDR;
      if (hex.max > (FLASH_BASE_ADDR + buffer_size)) {
        serial->printf("abort - max address %08lX too large\n", hex.max);
        return;
      }
      else if (!IN_FLASH(buffer_addr)) {
        memcpy((void*)addr, (void*)hex.data, hex.num);
      }
      else if (IN_FLASH(buffer_addr)) {
        int error = flash_write_block(addr, hex.data, hex.num);
        if (error) {
          serial->printf("abort - error %02X in flash_write_block()\n", error);
          return;
        }
      }
    }
    hex.lines++;
  }

  //serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX)\n",
  //  hex.lines, hex.max - hex.min, hex.min, hex.max);
  serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX), %lu Msec\n",
    hex.lines, hex.max - hex.min, hex.min, hex.max, millis() - start_msec);

  // check FSEC value in new code -- abort if incorrect
#if defined(KINETISK) || defined(KINETISL)
  uint32_t value = *(uint32_t*)(0x40C + buffer_addr);
  if (value == 0xfffff9de) {
    serial->printf("new code contains correct FSEC value %08lX\n", value);
  }
  else {
    serial->printf("abort - FSEC value %08lX should be FFFFF9DE\n", value);
    return;
  }
#endif

  // check FLASH_ID in new code - abort if not found
  if (check_flash_id(buffer_addr, hex.max - hex.min)) {
    serial->printf("new code contains correct target ID %s\n", FLASH_ID);
  }
  else {
    serial->printf("abort - new code missing string %s\n", FLASH_ID);
    return;
  }

  // get user input to write to flash or abort
  int user_lines = -1;
  while (user_lines != hex.lines && user_lines != 0) {
    serial->printf("enter %d to flash or 0 to abort\n", hex.lines);
    read_ascii_line(serial, line, sizeof(line));
    sscanf(line, "%d", &user_lines);
  }

  if (user_lines == 0) {
    serial->printf("abort - user entered 0 lines\n");
    return;
  }

  // move new program from buffer to flash, free buffer, and reboot
  //serial->printf("user entered %d lines\n", user_lines);
  flash_move(FLASH_BASE_ADDR, buffer_addr, hex.max - hex.min);

  // should not return from flash_move(), but put REBOOT here as reminder
  REBOOT;
}

//******************************************************************************
// read_ascii_line()	read ascii characters until '\n', '\r', or max bytes
//******************************************************************************
void read_ascii_line(Stream* serial, char* line, int maxbytes)
{
  int c = 0, nchar = 0;
  while (nchar < maxbytes && !(c == '\n' || c == '\r')) {
    if (serial->available()) {
      c = serial->read();
      line[nchar++] = c;
    }
  }
  line[nchar - 1] = 0;	// null-terminate
}

//******************************************************************************
// process_hex_record()		process record and return okay (0) or error (1)
//******************************************************************************
int process_hex_record(hex_info_t* hex)
{
  if (hex->code == 0) { // data -- update min/max address so far
    if (hex->base + hex->addr + hex->num > hex->max)
      hex->max = hex->base + hex->addr + hex->num;
    if (hex->base + hex->addr < hex->min)
      hex->min = hex->base + hex->addr;
  }
  else if (hex->code == 1) { // EOF (:flash command not received yet)
    hex->eof = 1;
  }
  else if (hex->code == 2) { // extended segment address (top 16 of 24-bit addr)
    hex->base = ((hex->data[0] << 8) | hex->data[1]) << 4;
  }
  else if (hex->code == 3) { // start segment address (80x86 real mode only)
    return 1;
  }
  else if (hex->code == 4) { // extended linear address (top 16 of 32-bit addr)
    hex->base = ((hex->data[0] << 8) | hex->data[1]) << 16;
  }
  else if (hex->code == 5) { // start linear address (32-bit big endian addr)
    hex->base = (hex->data[0] << 24) | (hex->data[1] << 16)
      | (hex->data[2] << 8) | (hex->data[3] << 0);
  }
  else {
    return 1;
  }

  return 0;
}

//******************************************************************************
// Intel Hex record foramt:
//
// Start code:  one character, ASCII colon ':'.
// Byte count:  two hex digits, number of bytes (hex digit pairs) in data field.
// Address:     four hex digits
// Record type: two hex digits, 00 to 05, defining the meaning of the data field.
// Data:        n bytes of data represented by 2n hex digits.
// Checksum:    two hex digits, computed value used to verify record has no errors.
//
// Examples:
//  :10 9D30 00 711F0000AD38000005390000F5460000 35
//  :04 9D40 00 01480000 D6
//  :00 0000 01 FF
//******************************************************************************

/* Intel HEX read/write functions, Paul Stoffregen, paul@ece.orst.edu */
/* This code is in the public domain.  Please retain my name and */
/* email address in distributed copies, and let me know about any bugs */

/* I, Paul Stoffregen, give no warranty, expressed or implied for */
/* this software and/or documentation provided, including, without */
/* limitation, warranty of merchantability and fitness for a */
/* particular purpose. */

// type modifications by Jon Zeeff

/* parses a line of intel hex code, stores the data in bytes[] */
/* and the beginning address in addr, and returns a 1 if the */
/* line was valid, or a 0 if an error occured.  The variable */
/* num gets the number of bytes that were stored into bytes[] */

#include <stdio.h>		// sscanf(), etc.
#include <string.h>		// strlen(), etc.

int parse_hex_line(const char* theline, char* bytes,
  unsigned int* addr, unsigned int* num, unsigned int* code)
{
  unsigned sum, len, cksum;
  const char* ptr;
  int temp;

  *num = 0;
  if (theline[0] != ':')
    return 0;
  if (strlen(theline) < 11)
    return 0;
  ptr = theline + 1;
  if (!sscanf(ptr, "%02x", &len))
    return 0;
  ptr += 2;
  if (strlen(theline) < (11 + (len * 2)))
    return 0;
  if (!sscanf(ptr, "%04x", (unsigned int*)addr))
    return 0;
  ptr += 4;
  /* Serial1.printf("Line: length=%d Addr=%d\n", len, *addr); */
  if (!sscanf(ptr, "%02x", code))
    return 0;
  ptr += 2;
  sum = (len & 255) + ((*addr >> 8) & 255) + (*addr & 255) + (*code & 255);
  while (*num != len)
  {
    if (!sscanf(ptr, "%02x", &temp))
      return 0;
    bytes[*num] = temp;
    ptr += 2;
    sum += bytes[*num] & 255;
    (*num)++;
    if (*num >= 256)
      return 0;
  }
  if (!sscanf(ptr, "%02x", &cksum))
    return 0;

  if (((sum & 255) + (cksum & 255)) & 255)
    return 0;     /* checksum error */
  return 1;
}
#pragma endregion FLASHER_X

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Name: T35_WallE3_V2.ino

Created: 11/20/2021 4:41:25 PM

Author: FRANKNEWXPS15\Frank

Name: T35_WallE3_V1.ino

Created: 10/25/2021 2:37:04 PM

Author: FRANKNEWXPS15\Frank

10/30/21 - Added TeensyOTADemo code for basic OTA updates

Name: TeensyOTADemo.ino

Created: 10/9/2021 11:18:19 AM

Author: FRANKNEWXPS15\Frank

This program demonstrates the use of 'board.txt' post-build instructions in

conjunction with a small C# command-line program for seamless 'over-the-air' (OTA)

firmware update for Teensy modules.

Implementation of OTA update requires that Joe Pasquariello's 'FlasherX'

code be added to the Teensy sketch as it is below, and some code to allow

an external serial communications program to trigger the update process.

In the demo sketch below, the 'FlasherX' additions are the '#include FlasherTxx.h'

line and the addition of the FlasherX specific code at the bottom. The trigger

mechanism is provided by the 'CheckForUserInput();' call in loop. If the ASCII

code for 'U' or 'u' is present on Serial1, the update process will be launched.

#pragma region INCLUDES

#include "FlashTxx.h" // TLC/T3x/T4x flash primitives

#include <elapsedMillis.h>

#include "MPU6050_6Axis_MotionApps_V6_12.h" //changed to this version 10/05/19

#pragma endregion Includes

#pragma region DEFINES

//02/29/16 hardware defines

//#define NO_MOTORS

//#define IR_HOMING_ONLY

//#define NO_LIDAR

//#define NO_PINGS

//#define NO_IRDET //added 04/05/17 for daytime in-atrium testing (too much ambient IR)

//#define DISTANCES_ONLY //added 11/14/18 to just display distances in infinite loop

#define NO_STUCK //added 03/10/19 to disable 'stuck' detection

//#define BATTERY_DISCHARGE //added 03/04/20 to discharge battery safely

#define NO_POST //added 04/12/20 to skip all the POST checks

//11/07/2020 moved all I2C Address declarations here

#define IRDET_I2C_ADDR 0x08

#define MPU6050_I2C_ADDR 0x68

#pragma endregion Program #Defines

#pragma region PRE_SETUP

MPU6050 mpu(MPU6050_I2C_ADDR);

elapsedMillis MsecSinceLastLEDToggle; //used for LED blink timer

const double ADC_REF_VOLTS = 3.3; //teensy default for analog inputs

const double AmpsPerVolt = 1.00; //default 10K Rs

const int MAX_AD_COUNT = 1023;

const double VoltsPerCount = ADC_REF_VOLTS / MAX_AD_COUNT;

//Battery constants

const float ZENER_VOLTAGE_OFFSET = 5.84; //measured zener voltage

#pragma region PIN ASSIGNMENTS

//vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv//

//=================== START PIN ASSIGNMENTS ===================//

//vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv//

#pragma region MOTOR_PINS

//11/04/21 Now using Pololu VNH5019 drivers for all 4 motors

const int InA_Left = 22;

const int InB_Left = 21;

const int Spd_Left = 23;

const int InA_Right = 34;

const int InB_Right = 33;

const int Spd_Right = 35;

#pragma endregion Motor Pin Assignments

const int ChgConnectPin = 36;

const int ItotPin = A1;

const int IRunPin = A2;

const int BATT_MON_PIN = A0;

#pragma endregion PIN ASSIGNMENTS

#pragma region MOTOR_PARAMETERS

//drive wheel speed parameters

const int MOTOR_SPEED_FULL = 200; //range is 0-255

const int MOTOR_SPEED_MAX = 255; //range is 0-255

const int MOTOR_SPEED_HALF = 127; //range is 0-255

const int MOTOR_SPEED_QTR = 75; //added 09/25/20

const int MOTOR_SPEED_LOW = 50; //added 01/22/15

const int MOTOR_SPEED_OFF = 0; //range is 0-255

const int MOTOR_SPEED_CAPTURE_OFFSET = 75; //added 06/21/20 for offset capture

const int TURN_START_SPEED = MOTOR_SPEED_QTR; //added 11/14/21

//drive wheel direction constants

const boolean FWD_DIR = true;

const boolean REV_DIR = !FWD_DIR;

const bool TURNDIR_CCW = true;

const bool TURNDIR_CW = false;

//Motor direction variables

bool bIsForwardDir = true; //default is foward direction

#pragma endregion Motor Parameters

#pragma region MPU6050_SUPPORT

uint8_t mpuIntStatus; // holds actual interrupt status byte from MPU. Used in Homer's Overflow routine

uint8_t devStatus; // return status after each device operation (0 = success, !0 = error)

uint16_t packetSize; // expected DMP packet size (default is 42 bytes)

uint16_t fifoCount; // count of all bytes currently in FIFO

uint8_t fifoBuffer[64]; // FIFO storage buffer

// orientation/motion vars

Quaternion q; // [w, x, y, z] quaternion container

VectorInt16 aa; // [x, y, z] accel sensor measurements

VectorInt16 aaReal; // [x, y, z] gravity-free accel sensor measurements

VectorInt16 aaWorld; // [x, y, z] world-frame accel sensor measurements

VectorFloat gravity; // [x, y, z] gravity vector

float euler[3]; // [psi, theta, phi] Euler angle container

float ypr[3]; // [yaw, pitch, roll] yaw/pitch/roll container and gravity vector

int GetPacketLoopCount = 0;

int OuterGetPacketLoopCount = 0;

//MPU6050 status flags

bool bMPU6050Ready = true;

bool dmpReady = false; // set true if DMP init was successful

volatile float IMUHdgValDeg = 0; //updated by UpdateIMUHdgValDeg()//11/02/20 now updated in ISR

const uint16_t MAX_GETPACKET_LOOPS = 100; //10/30/19 added for backup loop exit condition in GetCurrentFIFOPacket()

uint8_t GetCurrentFIFOPacket(uint8_t* data, uint8_t length, uint16_t max_loops = MAX_GETPACKET_LOOPS); //prototype here so can define a default param

bool bFirstTime = true;

//#define MPU6050_CCW_INCREASES_YAWVAL //added 12/05/19 commented out 11/22/21 as now the MPU6050 module is mounted 'Z-up'

#pragma endregion MPU6050 Support

#pragma region HEADING_AND_RATE_BASED_TURN_PARAMETERS

elapsedMillis MsecSinceLastTurnRateUpdate;

const int MAX_SPIN_MOTOR_SPEED = 250;

const int MIN_SPIN_MOTOR_SPEED = 50;

const int TURN_RATE_UPDATE_INTERVAL_MSEC = 30; //30 mSec is as fast as it can go

double TurnRateOutput;

double TurnRateSetPoint_DPS;

double Ival = 0;

double lastErr = 0;

double lastTurnRateVal_DPS;

double TurnRateVal_DPS;

double Prev_HdgDeg = 0;

float tgt_deg;

float timeout_sec;

//11/16/21 almost perfect for 45 deg/sec, 100mSec

//11/17/21 and pretty good for 90 deg/sec too!

double TurnRate_Kp = 1.8;

double TurnRate_Ki = 1.0;

double TurnRate_Kd = 0.4;

//ported from FourWD_PulseTurnRateTest.ino

double TurnRatePIDOutput;

//06/02/

const float HDG_NEAR_MATCH_VAL = 0.8; //slow the turn down here

const float HDG_FULL_MATCH_VAL = 0.99; //stop the turn here //rev 06/01/21

const float HDG_MIN_MATCH_VAL = 0.6; //added 09/08/18: don't start checking slope until turn is well started

#pragma endregion HEADING_AND_RATE_BASED_TURN_PARAMETERS

#pragma region OTA UPDATE

//******************************************************************************

// hex_info_t struct for hex record and hex file info

//******************************************************************************

typedef struct { //

char* data; // pointer to array allocated elsewhere

unsigned int addr; // address in intel hex record

unsigned int code; // intel hex record type (0=data, etc.)

unsigned int num; // number of data bytes in intel hex record

uint32_t base; // base address to be added to intel hex 16-bit addr

uint32_t min; // min address in hex file

uint32_t max; // max address in hex file

int eof; // set true on intel hex EOF (code = 1)

int lines; // number of hex records received

} hex_info_t;

void read_ascii_line(Stream* serial, char* line, int maxbytes);

int parse_hex_line(const char* theline, char* bytes,

unsigned int* addr, unsigned int* num, unsigned int* code);

int process_hex_record(hex_info_t* hex);

void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size);

uint32_t buffer_addr, buffer_size; //09/20/21 copied from FlasherX - loop()

#pragma endregion OTA UPDATE

#pragma endregion PRE_SETUP

void setup()

{

Serial.begin(115200);

delay(2000); //10/06/21 - just use fixed delay instead

Serial1.begin(115200); //used HC-05 'AT' commands to set this speed

//while (!Serial1) {}

delay(2000); //11/20/21 use fixed delay instead of waiting

Wire.begin(I2C_MASTER, 0x00, I2C_PINS_18_19, I2C_PULLUP_EXT, 400000);

//DEBUG!!

if (Serial)

{

Serial.printf("Serial = %p, Serial1 = %p\n", &Serial, &Serial1);

}

//DEBUG!!

if (Serial1)

{

Serial.printf("Serial = %p, Serial1 = %p\n", &Serial, &Serial1);

}

//DEBUG!!

#pragma region PIN INITIALIZATION

pinMode(LED_BUILTIN, OUTPUT);

pinMode(ItotPin, INPUT); //I_total 1V/Amp

pinMode(BATT_MON_PIN, INPUT); //Battery voltage monitor

//motor pins

pinMode(InA_Left, OUTPUT);

pinMode(InB_Left, OUTPUT);

pinMode(Spd_Left, OUTPUT);

pinMode(InA_Right, OUTPUT);

pinMode(InB_Right, OUTPUT);

pinMode(Spd_Right, OUTPUT);

#pragma endregion PIN INITIALIZATION

#pragma region MPU6050

Serial.printf("\nChecking for MPU6050 IMU at I2C Addr 0x%x\n", MPU6050_I2C_ADDR);

mpu.initialize();

// verify connection

Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));

float StartSec = 0; //used to time MPU6050 init

Serial.println(F("Initializing DMP..."));

devStatus = mpu.dmpInitialize();

// make sure it worked (returns 0 if successful)

if (devStatus == 0)

{

// turn on the DMP, now that it's ready

Serial.println(F("Enabling DMP..."));

mpu.setDMPEnabled(true);

// set our DMP Ready flag so the main loop() function knows it's okay to use it

Serial.println(F("DMP ready! Waiting for MPU6050 drift rate to settle..."));

dmpReady = true;

// get expected DMP packet size for later comparison

packetSize = mpu.dmpGetFIFOPacketSize();

Serial.printf("Just after MPU6050 Init\n");

Serial.printf("Calibrating...\n");

mpu.CalibrateGyro(); //using default value of 15

Serial.printf("Retrieving Calibration Values\n\n");

mpu.PrintActiveOffsets();

//loop heading display until stabilized

Serial.printf("\nMsec\tHdg\n");

UpdateIMUHdgValDeg();

Prev_HdgDeg = IMUHdgValDeg;

delay(100);

UpdateIMUHdgValDeg();

Serial.printf("%lu\t%2.3f\t%2.3f\n", millis(), IMUHdgValDeg, Prev_HdgDeg);

while (abs(IMUHdgValDeg - Prev_HdgDeg) > 0.1f)

{

Serial.printf("%lu\t%2.3f\n", millis(), IMUHdgValDeg);

Prev_HdgDeg = IMUHdgValDeg;

delay(100);

UpdateIMUHdgValDeg();

}

StartSec = millis() / 1000.f;

Serial.printf("MPU6050 Ready at %2.2f Sec with delta = %2.3f\n", StartSec, IMUHdgValDeg - Prev_HdgDeg);

bMPU6050Ready = true;

delay(1000);

}

else //MPU6050 Init failed for some reason

{

// ERROR!

// 1 = initial memory load failed

// 2 = DMP configuration updates failed

// (if it's going to break, usually the code will be 1)

Serial.print(F("DMP Initialization failed (code "));

Serial.print(devStatus);

Serial.println(F(")"));

//08/29/21 print out battery voltage on failure

float batV = GetBattVoltage();

Serial.printf("Battery Voltage = %2.2f\n", batV);

bMPU6050Ready = false;

}

#pragma endregion MPU6050

analogReadAveraging(4); //applies to all analogRead() operations?

MsecSinceLastLEDToggle = 0;

Serial1.printf("Msec\tBattV\tTotAmps\tRunAmps\tHdgDeg\n");

}

void loop()

{

//if (Serial1.available())

if (Serial1.available()||Serial.available())

{

CheckForUserInput();

}

if (MsecSinceLastLEDToggle >= 200)

{

MsecSinceLastLEDToggle -= 200;

digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));

//11/01/21 read I_tot value & cvt to current

int ItotVal = analogRead(ItotPin);

double ItotVolts = ItotVal * VoltsPerCount;

double ItotAmps = ItotVolts * AmpsPerVolt;

//Get battery voltage

float calc_volts = GetBattVoltage();

//print out battery voltage & charge current

Serial1.printf("%lu\t%2.2f\t%2.2f\n", millis(), calc_volts, ItotAmps);

Serial.printf("%lu\t%2.2f\t%2.2f\n", millis(), calc_volts, ItotAmps);

}

float GetBattVoltage()

{

//02/18/17 get corrected battery voltage. Voltage reading is 1/3 actual Vbatt value

//int analog_batt_reading = GetAverageAnalogReading(BATT_MON_PIN, VOLTS_AVERAGE_NUMBER);//rev 03/01/19 to average readings

int analog_batt_reading = analogRead(BATT_MON_PIN);//analogReadAveraging(4) in setup() does internal averaging

float calc_volts = ZENER_VOLTAGE_OFFSET + ADC_REF_VOLTS * (double)analog_batt_reading / (double)MAX_AD_COUNT;

////DEBUG!!

// Serial1.printf("a/d = %d, calc = %2.2f\n", analog_batt_reading,calc_volts);

////DEBUG!!

return calc_volts;

}

//void CheckForUserInput()

//{

// //Notes:

// // 11/21/21 rev to accomodate cmd input from either serial, and output to both

// const int bufflen = 80;

// char buff[bufflen];

// memset(buff, 0, bufflen);

// float OffsetCm;

// float Kp, Ki, Kd;

// const char s[2] = ",";

// char* token;

// byte incomingByte = 0; //moved here 11/21/21

// if (Serial.available() > 0)

// {

// // read the incoming byte:

// //int incomingByte = Serial.read();

// incomingByte = Serial.read();

// // say what you got:

// Serial.print("I received: ");

// Serial.println(incomingByte, HEX); //chg to HEX 02/18/20

// }

// //11/21/21 now input can come from Serial1 too

// else if (Serial1.available() > 0)

// {

// // read the incoming byte:

// incomingByte = Serial1.read();

// // say what you got:

// Serial1.print("I received: ");

// Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20

// }

// //11/21/21 incomingByte can come from either serial input

// if (incomingByte != 0)

// {

// //02/18/20 experiment with multiple commands

// switch (incomingByte)

// {

// case 0x55: //ASCII 'U'

// case 0x75: //ASCII 'u'

//#pragma region FIRMWARE UPDATE

// Serial1.println(F("Start Program Update - Send new HEX file!"));

// //09/20/21 copied from FlasherX - loop()

// if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)

// {

// Serial1.printf("unable to create buffer\n");

// Serial1.flush();

// for (;;) {}

// }

// Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",

// buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",

// buffer_addr, buffer_addr + buffer_size);

// //09/20/21 clear the serial buffer

// while (Serial1.available())

// {

// Serial1.read();

// }

// // receive hex file via serial, write new firmware to flash, clean up, reboot

// update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success

// // return from update_firmware() means error or user abort, so clean up and

// // reboot to ensure that static vars get boot-up initialized before retry

// Serial1.printf("erase FLASH buffer / free RAM buffer...\n");

// firmware_buffer_free(buffer_addr, buffer_size);

// Serial1.flush();

// REBOOT;

// break;

//#pragma endregion FIRMWARE UPDATE

// case 0x43: //ASCII 'C'

// case 0x63: //ASCII 'c'

//#pragma region MANUALCONTROL

// //enter infinite loop for direct remote control

// Serial.println(F("ENTERING COMMAND MODE:"));

// Serial.println(F("0 = 180 deg CCW Turn"));

// Serial.println(F("1 = 180 deg CW Turn"));

// Serial.println(F("A = Back to Auto Mode"));

// Serial.println(F("S = Stop"));

// Serial.println(F("F = Forward"));

// Serial.println(F("R = Reverse"));

// Serial.println(F(""));

// Serial.println(F(" Faster"));

// Serial.println(F("\t8"));

// Serial.println(F("Left 4\t5 6 Right"));

// Serial.println(F("\t2"));

// Serial.println(F(" Slower"));

// Serial1.println(F("ENTERING COMMAND MODE:"));

// Serial1.println(F("0 = 180 deg CCW Turn"));

// Serial1.println(F("1 = 180 deg CW Turn"));

// Serial1.println(F("A = Back to Auto Mode"));

// Serial1.println(F("S = Stop"));

// Serial1.println(F("F = Forward"));

// Serial1.println(F("R = Reverse"));

// Serial1.println(F(""));

// Serial1.println(F(" Faster"));

// Serial1.println(F("\t8"));

// Serial1.println(F("Left 4\t5 6 Right"));

// Serial1.println(F("\t2"));

// Serial1.println(F(" Slower"));

// StopBothMotors();

// int speed = 0;

// bool bAutoMode = false;

// while (!bAutoMode)

// {

// if (Serial.available() > 0)

// {

// // read the incoming byte:

// incomingByte = Serial.read();

// // say what you got:

// Serial.print("I received: ");

// Serial.println(incomingByte, HEX); //chg to HEX 02/18/20

// }

// //11/21/21 now input can come from Serial1 too

// else if (Serial1.available() > 0)

// {

// // read the incoming byte:

// incomingByte = Serial1.read();

// // say what you got:

// Serial1.print("I received: ");

// Serial1.println(incomingByte, HEX); //chg to HEX 02/18/20

// }

// //11/21/21 incomingByte can come from either serial input

// if (incomingByte != 0)

// {

// switch (incomingByte)

// {

// case 0x30: //Dec '0'

// Serial.println(F("CCW 180 deg Turn"));

// Serial1.println(F("CCW 180 deg Turn"));

// SpinTurn(true, 180, 90);

// MoveAhead(speed, speed);

// break;

// case 0x31: //Dec '1'

// Serial.println(F("CW 180 deg Turn"));

// Serial1.println(F("CW 180 deg Turn"));

// SpinTurn(false, 180, 45);

// break;

// case 0x34: //Turn left 10 deg and keep moving

// Serial.println(F("CCW 10 deg Turn"));

// Serial1.println(F("CCW 10 deg Turn"));

// SpinTurn(true, 10, 30);

// if (bIsForwardDir)

// {

// MoveAhead(speed, speed);

// }

// else

// {

// MoveReverse(speed, speed);

// }

// break;

// case 0x36: //Turn right 10 deg and keep moving

// Serial.print("CW 10 deg Turn\n");

// Serial1.print("CW 10 deg Turn\n");

// SpinTurn(false, 10, 30);

// //added 05/03/20

// if (bIsForwardDir)

// {

// MoveAhead(speed, speed);

// }

// else

// {

// MoveReverse(speed, speed);

// }

// break;

// case 0x38: //Speed up

// speed += 50;

// speed = (speed >= MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : speed;

// Serial.printf("Speeding up: speed now %d\n", speed);

// Serial1.printf("Speeding up: speed now %d\n", speed);

// if (bIsForwardDir)

// {

// MoveAhead(speed, speed);

// }

// else

// {

// MoveReverse(speed, speed);

// }

// break;

// case 0x32: //Slow down

// speed -= 50;

// speed = (speed < 0) ? 0 : speed;

// Serial.printf("Slowing down: speed now %d\n", speed);

// Serial1.printf("Slowing down: speed now %d\n", speed);

// if (bIsForwardDir)

// {

// MoveAhead(speed, speed);

// }

// else

// {

// MoveReverse(speed, speed);

// }

// break;

// case 0x35: //05/07/20 changed to use '5' vs 'S'

// Serial.println(F("Stopping Motors!"));

// Serial1.println(F("Stopping Motors!"));

// StopBothMotors();

// speed = 0;

// break;

// case 0x41: //ASCII 'A'

// case 0x61: //ASCII 'a'

// StopBothMotors();

// Serial.println(F("Re-entering AUTO mode"));

// Serial1.println(F("Re-entering AUTO mode"));

// bAutoMode = true;

// break;

// case 0x52: //ASCII 'R'

// case 0x72: //ASCII 'r'

// Serial.println(F("Setting both motors to reverse"));

// Serial1.println(F("Setting both motors to reverse"));

// bIsForwardDir = false;

// //MoveReverse(speed, speed);

// break;

// case 0x46: //ASCII 'F'

// case 0x66: //ASCII 'f'

// Serial.println(F("Setting both motors to forward"));

// Serial1.println(F("Setting both motors to forward"));

// bIsForwardDir = true;

// MoveAhead(speed, speed);

//#pragma endregion MANUALCONTROL

// break;

//#pragma region WALL OFFSET TRACKING CASES

// //left side wall tracking

// case 0x4C: //ASCII 'L'

// case 0x6C: //ASCII 'l'

// StopBothMotors();

// Serial.println(F("Setting Kp value"));

// //consume CR/LF chars

// while (Serial.available() > 0)

// {

// int byte = Serial.read();

// Serial.printf("consumed %d\n", byte);

// }

// while (!Serial.available())

// {

// }

// Serial.readBytes(buff, bufflen);

// Serial.printf("%s\n", buff);

// /* extract Kp */

// token = strtok(buff, s);

// Kp = atof(token);

// /* extract Ki */

// token = strtok(NULL, s);

// Ki = atof(token);

// /* extract Kd */

// token = strtok(NULL, s);

// Kd = atof(token);

// /* extract Offset in cm */

// token = strtok(NULL, s);

// OffsetCm = atof(token);

// Serial.printf("Kp,Ki,Kd,OffsetCm = %2.2f, %2.2f, %2.2f, %2.2f\n",

// Kp, Ki, Kd, OffsetCm);

// //TrackLeftWallOffset(Kp, Ki, Kd, OffsetCm);

// break;

// case 0x4D: //ASCII 'M'

// case 0x6D: //ASCII 'm'

// StopBothMotors();

// Serial.println(F("Setting Kp value"));

// //consume CR/LF chars

// while (Serial.available() > 0)

// {

// int byte = Serial.read();

// Serial.printf("consumed %d\n", byte);

// }

// while (!Serial.available())

// {

// }

// Serial.readBytes(buff, bufflen);

// Serial.printf("%s\n", buff);

// /* extract Kp */

// token = strtok(buff, s);

// Kp = atof(token);

// /* extract Ki */

// token = strtok(NULL, s);

// Ki = atof(token);

// /* extract Kd */

// token = strtok(NULL, s);

// Kd = atof(token);

// /* extract Offset in cm */

// token = strtok(NULL, s);

// OffsetCm = atof(token);

// Serial.printf("Kp,Ki,Kd,OffsetCm = %2.2f, %2.2f, %2.2f, %2.2f\n",

// Kp, Ki, Kd, OffsetCm);

// //TrackRightWallOffset(Kp, Ki, Kd, OffsetCm);

// break;

//#pragma endregion WALL OFFSET TRACKING CASES

// default:

// Serial.println(F("In Default Case: Stopping Motors!"));

// Serial1.println(F("In Default Case: Stopping Motors!"));

// StopBothMotors();

// while (true)

// {

// }

//}

void CheckForUserInput()

{

//Notes:

// 11/21/21 rev to accomodate cmd input from either serial, and output to both

const int bufflen = 3;

char buff[bufflen];

memset(buff, 0, bufflen);

byte incomingByte = 0; //moved here 11/21/21

int numchars = 0;

if (Serial.available() > 0)

{

// read the incoming byte:

//incomingByte = Serial.read();

numchars = Serial.readBytesUntil('\n', buff, sizeof(buff));

incomingByte = buff[0];

// say what you got:

Serial.printf("I received %d chars, first char 0X%X on Serial\n", numchars, incomingByte);

}

//11/21/21 now input can come from Serial1 too

else if (Serial1.available() > 0)

{

// read the incoming byte:

//incomingByte = Serial1.read();

numchars = Serial1.readBytesUntil('\n', buff, sizeof(buff));

incomingByte = buff[0];

// say what you got:

Serial1.printf("I received %d chars, first char 0X%X on Serial1\n", numchars, incomingByte);

}

//11/21/21 incomingByte can come from either serial input

if (incomingByte != 0)

{

//02/18/20 experiment with multiple commands

switch (incomingByte)

{

case 0x55: //ASCII 'U'

case 0x75: //ASCII 'u'

#pragma region FIRMWARE UPDATE

Serial1.println(F("Start Program Update - Send new HEX file!"));

//09/20/21 copied from FlasherX - loop()

if (firmware_buffer_init(&buffer_addr, &buffer_size) == 0)

{

Serial1.printf("unable to create buffer\n");

Serial1.flush();

for (;;) {}

}

Serial1.printf("buffer = %1luK %s (%08lX - %08lX)\n",

buffer_size / 1024, IN_FLASH(buffer_addr) ? "FLASH" : "RAM",

buffer_addr, buffer_addr + buffer_size);

//09/20/21 clear the serial buffer

while (Serial1.available())

{

Serial1.read();

}

// receive hex file via serial, write new firmware to flash, clean up, reboot

update_firmware(&Serial1, buffer_addr, buffer_size); // no return if success

// return from update_firmware() means error or user abort, so clean up and

// reboot to ensure that static vars get boot-up initialized before retry

Serial1.printf("erase FLASH buffer / free RAM buffer...\n");

firmware_buffer_free(buffer_addr, buffer_size);

Serial1.flush();

REBOOT;

break;

#pragma endregion FIRMWARE UPDATE

case 0x43: //ASCII 'C'

case 0x63: //ASCII 'c'

#pragma region MANUALCONTROL

//enter infinite loop for direct remote control

Serial.println(F("ENTERING COMMAND MODE:"));

Serial.println(F("0 = 180 deg CCW Turn"));

Serial.println(F("1 = 180 deg CW Turn"));

Serial.println(F("A = Back to Auto Mode"));

Serial.println(F("S = Stop"));

Serial.println(F("F = Forward"));

Serial.println(F("R = Reverse"));

Serial.println(F(""));

Serial.println(F(" Faster"));

Serial.println(F("\t8"));

Serial.println(F("Left 4\t5 6 Right"));

Serial.println(F("\t2"));

Serial.println(F(" Slower"));

Serial1.println(F("ENTERING COMMAND MODE:"));

Serial1.println(F("0 = 180 deg CCW Turn"));

Serial1.println(F("1 = 180 deg CW Turn"));

Serial1.println(F("A = Back to Auto Mode"));

Serial1.println(F("S = Stop"));

Serial1.println(F("F = Forward"));

Serial1.println(F("R = Reverse"));

Serial1.println(F(""));

Serial1.println(F(" Faster"));

Serial1.println(F("\t8"));

Serial1.println(F("Left 4\t5 6 Right"));

Serial1.println(F("\t2"));

Serial1.println(F(" Slower"));

StopBothMotors();

int speed = 0;

bool bAutoMode = false;

while (Serial.available())

{

incomingByte = Serial.read();

//Serial.printf("I removed 0X%X from Serial\n",incomingByte);

}

while (Serial1.available())

{

incomingByte = Serial1.read();

//Serial1.printf("I removed 0X%X from Serial1\n", incomingByte);

}

incomingByte = 0;

while (!bAutoMode)

{

if (Serial.available() > 0)

{

// read the incoming bytes:

numchars = Serial.readBytesUntil('\n', buff, sizeof(buff));

incomingByte = buff[0];

// say what you got:

Serial.printf("I received %d chars, first char 0X%X on Serial\n", numchars, incomingByte);

while (Serial.available())

{

Serial.read();

Serial.printf("I removed 0X%X from Serial\n",incomingByte);

}

//11/21/21 now input can come from Serial1 too

else if (Serial1.available() > 0)

{

// read the incoming bytes:

numchars = Serial1.readBytesUntil('\n', buff, sizeof(buff));

incomingByte = buff[0];

// say what you got:

Serial1.printf("I received %d chars, first char 0X%X on Serial1\n", numchars, incomingByte);

while (Serial1.available())

{

Serial1.read();

Serial1.printf("I removed 0X%X from Serial1\n", incomingByte);

}

//11/21/21 incomingByte can come from either serial input

if (incomingByte != 0)

{

switch (incomingByte)

{

case 0x30: //Dec '0'

Serial.println(F("CCW 180 deg Turn"));

Serial1.println(F("CCW 180 deg Turn"));

SpinTurn(true, 180, 90);

MoveAhead(speed, speed);

break;

case 0x31: //Dec '1'

Serial.println(F("CW 180 deg Turn"));

Serial1.println(F("CW 180 deg Turn"));

SpinTurn(false, 180, 45);

break;

case 0x34: //Turn left 10 deg and keep moving

Serial.println(F("CCW 10 deg Turn"));

Serial1.println(F("CCW 10 deg Turn"));

SpinTurn(true, 10, 30);

if (bIsForwardDir)

{

MoveAhead(speed, speed);

}

else

{

MoveReverse(speed, speed);

}

break;

case 0x36: //Turn right 10 deg and keep moving

Serial.print("CW 10 deg Turn\n");

Serial1.print("CW 10 deg Turn\n");

SpinTurn(false, 10, 30);

//added 05/03/20

if (bIsForwardDir)

{

MoveAhead(speed, speed);

}

else

{

MoveReverse(speed, speed);

}

break;

case 0x38: //Speed up

speed += 50;

speed = (speed >= MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : speed;

Serial.printf("Speeding up: speed now %d\n", speed);

Serial1.printf("Speeding up: speed now %d\n", speed);

if (bIsForwardDir)

{

MoveAhead(speed, speed);

}

else

{

MoveReverse(speed, speed);

}

break;

case 0x32: //Slow down

speed -= 50;

speed = (speed < 0) ? 0 : speed;

Serial.printf("Slowing down: speed now %d\n", speed);

Serial1.printf("Slowing down: speed now %d\n", speed);

if (bIsForwardDir)

{

MoveAhead(speed, speed);

}

else

{

MoveReverse(speed, speed);

}

break;

case 0x35: //05/07/20 changed to use '5' vs 'S'

Serial.println(F("Stopping Motors!"));

Serial1.println(F("Stopping Motors!"));

StopBothMotors();

speed = 0;

break;

case 0x41: //ASCII 'A'

case 0x61: //ASCII 'a'

StopBothMotors();

Serial.println(F("Re-entering AUTO mode"));

Serial1.println(F("Re-entering AUTO mode"));

bAutoMode = true;

break;

case 0x52: //ASCII 'R'

case 0x72: //ASCII 'r'

Serial.println(F("Setting both motors to reverse"));

Serial1.println(F("Setting both motors to reverse"));

bIsForwardDir = false;

//MoveReverse(speed, speed);

break;

case 0x46: //ASCII 'F'

case 0x66: //ASCII 'f'

Serial.println(F("Setting both motors to forward"));

Serial1.println(F("Setting both motors to forward"));

bIsForwardDir = true;

MoveAhead(speed, speed);

#pragma endregion MANUALCONTROL

break;

default:

Serial.println(F("In Default Case: Stopping Motors!"));

Serial1.println(F("In Default Case: Stopping Motors!"));

StopBothMotors();

//while (true)

//{

//}

}

incomingByte = 0;

}

#pragma region MOTOR SUPPORT

//09/08/20 modified for DRV8871 motor driver

void MoveReverse(int leftspeednum, int rightspeednum)

{

//Purpose: Move in reverse direction continuously - companion to MoveAhead()

//ProvEnA_Pinnce: G. Frank Paynter 09/08/18

//Inputs:

// leftspeednum = integer denoting speed (0=stop, 255 = full speed)

// rightspeednum = integer denoting speed (0=stop, 255 = full speed)

//Outputs: both drive Motors energized with the specified speed

//Plan:

// Step 1: Set reverse direction for both wheels

// Step 2: Run both Motors at specified speeds

//Notes:

// 01/22/20 now using Adafruit DRV8871 drivers

//Step 1: Set reverse direction and speed for both wheels

SetLeftMotorDirAndSpeed(REV_DIR, leftspeednum);

SetRightMotorDirAndSpeed(REV_DIR, rightspeednum);

}

//09/08/20 modified for DRV8871 motor driver

void MoveAhead(int leftspeednum, int rightspeednum)

{

//Purpose: Move ahead continuously

//ProvEnA_Pinnce: G. Frank Paynter and Danny Frank 01/24/2014

//Inputs:

// leftspeednum = integer denoting speed (0=stop, 255 = full speed)

// rightspeednum = integer denoting speed (0=stop, 255 = full speed)

//Outputs: both drive Motors energized with the specified speed

//Plan:

// Step 1: Set forward direction for both wheels

// Step 2: Run both Motors at specified speeds

//Notes:

// 01/22/20 now using Adafruit DRV8871 drivers

//Serial1.printf("InMoveAhead(%d,%d)\n", leftspeednum, rightspeednum);

//Step 1: Set forward direction and speed for both wheels

SetLeftMotorDirAndSpeed(true, leftspeednum);

SetRightMotorDirAndSpeed(true, rightspeednum);

}

//09/08/20 modified for DRV8871 motor driver

//11/04/21 modified for Pololu VNH5019 motor driver

void StopLeftMotors()

{

digitalWrite(InA_Left, LOW);

digitalWrite(InB_Left, LOW);

analogWrite(Spd_Left, MOTOR_SPEED_OFF);

}

//11/04/21 modified for Pololu VNH5019 motor driver

void StopRightMotors()

{

digitalWrite(InA_Right, LOW);

digitalWrite(InB_Right, LOW);

analogWrite(Spd_Right, MOTOR_SPEED_OFF);

}

//09/08/20 added bool bisFwd param for DRV8871 motor driver

void RunBothMotors(bool bisFwd, int leftspeednum, int rightspeednum)

{

//Purpose: Run both Motors at left/rightspeednum speeds

//Inputs:

// speednum = speed value (0 = OFF, 255 = full speed)

//Outputs: Both Motors run for timesec seconds at speednum speed

//Plan:

// Step 1: Apply drive to both wheels

//Notes:

// 01/14/15 - added left/right speed offset for straightness compensation

// 01/22/15 - added code to restrict fast/slow values

// 01/24/15 - revised for continuous run - no timing

// 01/26/15 - speednum modifications moved to UpdateWallFollowmyMotorspeeds()

// 12/07/15 - chg args from &int to int

//Step 1: Apply drive to both wheels

//DEBUG!!

//Serial1.printf("In RunBothMotors(%s, %d,%d)\n", bisFwd? "FWD":"REV", leftspeednum, rightspeednum);

//DEBUG!!

SetLeftMotorDirAndSpeed(bisFwd, leftspeednum);

SetRightMotorDirAndSpeed(bisFwd, rightspeednum);

}

void RunBothMotorsBidirectional(int leftspeed, int rightspeed)

{

//Purpose: Accommodate the need for independent bidirectional wheel motion

//Inputs:

// leftspeed - integer denoting left wheel speed. Positive value is fwd, negative is rev

// rightspeed - integer denoting right wheel speed. Positive value is fwd, negative is rev

//Outputs:

// left/right wheel motors direction and speed set as appropriate

//Plan:

// Step1: Set left wheel direction and speed

// Step2: Set right wheel direction and speed

//Step1: Set left wheel direction and speed

//DEBUG!!

//Serial1.printf("In RunBothMotorsBidirectional(%d, %d)\n", leftspeed, rightspeed);

if (leftspeed < 0)

{

SetLeftMotorDirAndSpeed(false, -leftspeed); //neg value ==> reverse

}

else

{

SetLeftMotorDirAndSpeed(true, leftspeed); //pos or zero value ==> fwd

}

//Step2: Set right wheel direction and speed

if (rightspeed < 0)

{

SetRightMotorDirAndSpeed(false, -rightspeed); //neg value ==> reverse

}

else

{

SetRightMotorDirAndSpeed(true, rightspeed); //pos or zero value ==> fwd

}

//09/08/20 added bool bisFwd param for DRV8871 motor driver

void RunBothMotorsMsec(bool bisFwd, int timeMsec, int leftspeednum, int rightspeednum)

{

//Purpose: Run both Motors for timesec seconds at speednum speed

//Inputs:

// timesec = time in seconds to run the Motors

// speednum = speed value (0 = OFF, 255 = full speed)

//Outputs: Both Motors run for timesec seconds at speednum speed

//Plan:

// Step 1: Apply drive to both wheels

// Step 2: Delay timsec seconds

// Step 3: Remove drive from both wheels.

//Notes:

// 01/14/15 - added left/right speed offset for straightness compensation

// 01/22/15 - added code to restrict fast/slow values

// 11/25/15 - rev to use motor driver class object

// 09/08/20 added bool bisFwd param for DRV8871 motor driver

RunBothMotors(bisFwd, leftspeednum, rightspeednum);

//Step 2: Delay timsec seconds

delay(timeMsec);

//Step3: Stop motors added 04/12/21

StopBothMotors();

}

//11/25/15 added for symmetry ;-).

void StopBothMotors()

{

StopLeftMotors();

StopRightMotors();

}

void SetLeftMotorDirAndSpeed(bool bIsFwd, int speed)

{

//DEBUG!!

//Serial.printf("In SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

//11/04/21 fwd for right motors is CCW when looking at shaft

#ifndef NO_MOTORS

if (bIsFwd)

{

digitalWrite(InA_Left, LOW);

digitalWrite(InB_Left, HIGH);

analogWrite(Spd_Left, speed);

//DEBUG!!

//Serial.printf("In TRUE block of SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In TRUE block of SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

}

else

{

//DEBUG!!

//Serial.printf("In FALSE block of SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In FALSE block of SetLeftMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

digitalWrite(InA_Left, HIGH);

digitalWrite(InB_Left, LOW);

analogWrite(Spd_Left, speed);

}

#endif // !NO_MOTORS

}

void SetRightMotorDirAndSpeed(bool bIsFwd, int speed)

{

//DEBUG!!

//Serial.printf("In SetRightMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In SetRightMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

//11/04/21 fwd for right motors is CW when looking at shaft

#ifndef NO_MOTORS

if (bIsFwd)

{

//DEBUG!!

//Serial.printf("In TRUE block of SetRighttMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In TRUE block of SetRighttMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

digitalWrite(InA_Right, HIGH);

digitalWrite(InB_Right, LOW);

analogWrite(Spd_Right, speed);

}

else

{

//DEBUG!!

//Serial.printf("In FALSE block of SetRightMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//Serial1.printf("In FALSE block of SetRightMotorDirAndSpeed(%s, %d)\n",

// (bIsFwd == true) ? "true" : "false", speed);

//DEBUG!!

digitalWrite(InA_Right, LOW);

digitalWrite(InB_Right, HIGH);

analogWrite(Spd_Right, speed);

}

#endif // !NO_MOTORS

}

#pragma endregion Motor Support Functions

#pragma region HDG_BASED_TURN_SUPPORT

bool SpinTurn(bool b_ccw, float numDeg, float degPersec) //04/25/21 added turn-rate arg (default = TURN_RATE_TARGET_DEGPERSEC)

{

//Purpose: Make a numDeg CW or CCW 'spin' turn

//Inputs:

// b_ccw - True if turn is to be ccw, false otherwise

// numDeg - angle to be swept out in the turn

// ROLLING_TURN_MAX_SEC_PER_DEG = const used to generate timeout proportional to turn deg

// IMUHdgValDeg = IMU heading value updated by UpdateIMUHdgValDeg() //11/02/20 now updated in ISR

// degPerSec = float value denoting desired turn rate

//Plan:

// Step1: Get current heading as starting point

// Step2: Disable TIMER5 interrupts

// Step3: Compute new target value & timeout value

// Step4: Run motors until target reached, using inline PID algorithm to control turn rate

// Step5: Re-enable TIMER5 interrupts

//Notes:

// 06/06/21 we-written to remove PID library - now uses custom 'PIDCalcs()' function

// 06/06/21 added re-try for 180.00 return from IMU - could be bad value

// 06/11/21 added code to correct dHdg errors due to 179/-179 transition & bad IMU values

// 06/12/21 cleaned up & commented out debug code

// 11/14/21 removed 'first time skip' block; added motor start before entering loop

float tgt_deg;

float timeout_sec;

bool bDoneTurning = false;

bool bTimedOut = false;

bool bResult = true; //04/21/20 added so will be only one exit point

//DEBUG!!

Serial.printf("In SpinTurn(%s, %2.2f, %2.2f)\n", b_ccw == TURNDIR_CCW ? "CCW" : "CW", numDeg, degPersec);

Serial1.printf("In SpinTurn(%s, %2.2f, %2.2f)\n", b_ccw == TURNDIR_CCW ? "CCW" : "CW", numDeg, degPersec);

//Serial.printf("TurnRatePID started with Kp/Ki/Kd = %2.1f,%2.1f,%2.1f, SampleTime(mSec) = %d\n",

//TurnRate_Kp, TurnRate_Ki, TurnRate_Kd, TURN_RATE_UPDATE_INTERVAL_MSEC);

//DEBUG!!

//no need to continue if the IMU isn't available

if (!dmpReady)

{

Serial.printf("DMP Failure - returning FALSE\n");

return false;

}

//Step1: Get current heading as starting point

//06/06/21 it is possible for IMU to return 180.00 on failure

//so try again. If it really IS 180, then

//it will eventually time out and go on

//08/26/21 re-wrote using 3-value array to make sure initial heading is a steady value

UpdateIMUHdgValDeg();

int retries = 0;

if ((IMUHdgValDeg == 180.f || IMUHdgValDeg == 0.f) && retries < 5)

{

//DEBUG!!

Serial.printf("Got 180.00 or 0.00 exactly (%2.3f) from IMU - retrying %d...\n", IMUHdgValDeg, retries);

Serial1.printf("Got 180.00 or 0.00 exactly (%2.3f) from IMU - retrying %d...\n", IMUHdgValDeg, retries);

//DEBUG!!

UpdateIMUHdgValDeg();

retries++;

delay(100);

}

//Step2: Compute new target value & timeout value

//timeout_sec = 3 * numDeg / degPersec; //05/29/21 rev to use new turn rate parmeter

timeout_sec = 2 * numDeg / degPersec; //05/29/21 rev to use new turn rate parmeter

//05/17/20 limit timeout_sec to 1 sec or more

timeout_sec = (timeout_sec < 1) ? 1.f : timeout_sec;

//12/05/19 added #define back in to manage which direction increases yaw values

#ifdef MPU6050_CCW_INCREASES_YAWVAL

tgt_deg = b_ccw ? IMUHdgValDeg + numDeg : IMUHdgValDeg - numDeg;

#else

tgt_deg = b_ccw ? IMUHdgValDeg - numDeg : IMUHdgValDeg + numDeg;

#endif // MPU6050_CCW_INCREASES_YAWVAL

//correct for -180/180 transition

if (tgt_deg < -180)

{

tgt_deg += 360;

}

//07/29/19 bugfix

if (tgt_deg > 180)

{

tgt_deg -= 360;

}

//DEBUG!!

Serial.printf("Init hdg = %4.2f deg, Turn = %4.2f deg, tgt = %4.2f deg, timeout = %4.2f sec\n\n",

IMUHdgValDeg, numDeg, tgt_deg, timeout_sec);

Serial1.printf("Init hdg = %4.2f deg, Turn = %4.2f deg, tgt = %4.2f deg, timeout = %4.2f sec\n\n",

IMUHdgValDeg, numDeg, tgt_deg, timeout_sec);

//DEBUG!!

float curHdgMatchVal = 0;

//09/08/18 added to bolster end-of-turn detection

float prevHdgMatchVal = 0;

float matchSlope = 0;

//Step3: Run motors until target reached, using PID algorithm to control turn rate

Prev_HdgDeg = IMUHdgValDeg; //06/10/21 synch Prev_HdgDeg & IMUHdgValDeg just before entering loop

//11/14/21 start motors before entering loop. For CCW turn, left motors go backwards, right ones forward

int startSpd = (degPersec <= 45) ? TURN_START_SPEED : 2 * TURN_START_SPEED;

SetLeftMotorDirAndSpeed(!b_ccw, startSpd);

SetRightMotorDirAndSpeed(b_ccw, startSpd);

elapsedMillis sinceLastTimeCheck = 0;

elapsedMillis sinceLastComputeTime = 0;

double lastError = 0;

double lastInput = 0;

double lastIval = 0;

double lastDerror = 0;

//bool bFirstIMUHdg = true;

//DEBUG!!

Serial.printf("Msec\tHdg\tPrvHdg\tdHdg\tRate\ttgtDPS\terr\tKp*err\tIval\tKd*Derr\tspeed\tMatch\tSlope\n");

Serial1.printf("Msec\tHdg\tPrvHdg\tdHdg\tRate\ttgtDPS\terr\tKp*err\tIval\tKd*Derr\tspeed\tMatch\tSlope\n");

//DEBUG!!

while (!bDoneTurning && !bTimedOut)

{

//11/06/20 now just loops between PID calcs

CheckForUserInput();

if (sinceLastComputeTime >= TURN_RATE_UPDATE_INTERVAL_MSEC)

{

sinceLastComputeTime -= TURN_RATE_UPDATE_INTERVAL_MSEC;

UpdateIMUHdgValDeg(); //update IMUHdgValDeg

double dHdg = IMUHdgValDeg - Prev_HdgDeg;

if (dHdg > 180)

{

dHdg -= 360;

//Serial.printf("dHdg > 180 - subtracting 360\n");

}

else if (dHdg < -180)

{

dHdg += 360;

//Serial.printf("dHdg < -180 - adding 360\n");

}

//watch for turn rates that are wildly off

double rate = abs(1000 * dHdg / TURN_RATE_UPDATE_INTERVAL_MSEC);

//if (rate > 3 * degPersec)

//{

// //DEBUG!!

// Serial.printf("hdg/prevhdg/dHdg/rate = %2.2f\t%2.2f\t%2.2f\t%2.2f, excessive rate - replacing with %2.2f\n", IMUHdgValDeg, Prev_HdgDeg, dHdg, rate, degPersec);

// //DEBUG!!

// rate = degPersec;

//}

TurnRatePIDOutput = PIDCalcs(rate, degPersec, TURN_RATE_UPDATE_INTERVAL_MSEC, lastError, lastInput, lastIval, lastDerror, TurnRate_Kp, TurnRate_Ki, TurnRate_Kd);

int speed = 0;

(TurnRatePIDOutput > MOTOR_SPEED_MAX) ? speed = MOTOR_SPEED_MAX : speed = (int)TurnRatePIDOutput;

(TurnRatePIDOutput <= MOTOR_SPEED_LOW) ? speed = MOTOR_SPEED_LOW : speed = (int)TurnRatePIDOutput;

SetLeftMotorDirAndSpeed(!b_ccw, speed);

SetRightMotorDirAndSpeed(b_ccw, speed);

//check for nearly there and all the way there

curHdgMatchVal = GetHdgMatchVal(tgt_deg, IMUHdgValDeg);

matchSlope = curHdgMatchVal - prevHdgMatchVal;

Serial.printf("%lu\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%d\t%2.2f\t%2.2f\n",

millis(),

IMUHdgValDeg,

Prev_HdgDeg,

dHdg,

rate,

degPersec,

lastError,

TurnRate_Kp * lastError,

lastIval,

TurnRate_Kd * lastDerror,

speed,

curHdgMatchVal,

matchSlope);

Serial1.printf("%lu\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%d\t%2.2f\t%2.2f\n",

millis(),

IMUHdgValDeg,

Prev_HdgDeg,

dHdg,

rate,

degPersec,

lastError,

TurnRate_Kp * lastError,

lastIval,

TurnRate_Kd * lastDerror,

speed,

curHdgMatchVal,

matchSlope);

//DEBUG!!

Prev_HdgDeg = IMUHdgValDeg; //re-synch prev to curr hdg for next time

//look for full match

bDoneTurning = (curHdgMatchVal >= HDG_FULL_MATCH_VAL

|| (prevHdgMatchVal >= HDG_MIN_MATCH_VAL && matchSlope <= -0.01)); //have to use < vs <= as slope == 0 at start

//Serial.printf("curHdgMatchVal = %2.2f, prevHdgMatchVal = %2.2f, matchslope = %2.2f, bDoneTurning = %d\n",

// curHdgMatchVal,

// prevHdgMatchVal,

// matchSlope,

// bDoneTurning);

prevHdgMatchVal = curHdgMatchVal; //07/31/21 moved below bDoneTurning chk so can use prevHdgMatchVal vs curHdgMatchVal in slope check

bTimedOut = (sinceLastTimeCheck > timeout_sec * 1000);

if (bTimedOut)

{

//DEBUG!!

Serial.printf("timed out with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);

Serial1.printf("timed out with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);

//DEBUG!!

bResult = false;

break;

}

if (bDoneTurning)

{

Serial.printf("Completed turn with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);

Serial1.printf("Completed turn with yaw = %3.2f, tgt = %3.2f, and match = %1.3f\n", IMUHdgValDeg, tgt_deg, curHdgMatchVal);

bResult = true;

break;

}

StopBothMotors();

delay(1000); //added 04/27/21 for debug

return bResult;

}

double PIDCalcs(double input, double setpoint, uint16_t sampleTime, double& lastError, double& lastInput, double& lastIval, double& lastDerror, double Kp, double Ki, double Kd)

{

//Purpose: Encapsulate PID algorithm so can get rid of PID library. Library too cumbersome and won't synch with TIMER5 ISR

//Inputs:

// input = double denoting current input value (turn rate, speed, whatever)

// setpoint = double denoting desired setpoint in same units as input

// sampleTime = int denoting sample time to be used in calcs.

// lastError = ref to double denoting error saved from prev calc

// lastInput = ref to double denoting input saved from prev calc

// Kp/Ki/Kd = doubles denoting PID values to be used for calcs

// Output = ref to double denoting output from calc

double error = setpoint - input;

//double dInput = (input - lastInput);

//lastIval += (error);

lastIval += (Ki * error);

//11/16/21 rev to clamp integral term

lastIval = (lastIval > MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : lastIval;

lastIval = (lastIval < MOTOR_SPEED_OFF) ? MOTOR_SPEED_OFF : lastIval;

double dErr = (error - lastError);

//Serial.printf("PIDCalcs: error/dInput/lastIval/dErr/kp/ki/kd = %2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\t%2.2f\n", error, dInput, lastIval, dErr,

// Kp,Ki,Kd);

/*Compute PID Output*/

//11/16/21 rev to subtract differential term rather than add.

//double output = Kp * error + Ki * lastIval + Kd * dErr;

double output = Kp * error + lastIval - Kd * dErr;

//11/16/21 now clamping output value as well as I term

output = (output > MOTOR_SPEED_MAX) ? MOTOR_SPEED_MAX : output;

output = (output < MOTOR_SPEED_OFF) ? MOTOR_SPEED_OFF : output;

/*Remember some variables for next time*/

lastError = error;

lastInput = input;

lastDerror = dErr;

return output; //added 09/03/21

}

float GetHdgMatchVal(float tgt_deg, float cur_deg)

{

//Purpose: Compute the match ratio between two compass headings

//Inputs:

// tgt_deg = float representing target heading in +/-180 range

// IMUHdgValDeg = float representing sensor yaw value in +/-180 deg range

//Outputs:

// returns result of 1 - abs(Tgt_deg - Hdg_deg)/180, all angles in 0-360 deg range

//Plan:

// Step1: convert both inputs to 0-360 deg range

// Step2: compute match ratio

//Notes:

// formula from https://gis.stackexchange.com/questions/129954/comparing-compass-bearings

//Step1: convert both inputs to 0-360 deg range

float tgthdg = (tgt_deg < 0) ? tgt_deg + 360 : tgt_deg;

float curhdg = (cur_deg < 0) ? cur_deg + 360 : cur_deg;

//Step2: compute match ratio

float match_ratio = 1 - abs(tgthdg - curhdg) / 180;

//DEBUG!!

//Serial1.printf("tgt\tcur\tmatch = %4.2f\t%4.2f\t%1.3f\n", tgthdg, curhdg, match_ratio);

//DEBUG!!

return abs(match_ratio);

}

float UpdateIMUHdgValDeg()

{

//Purpose: Get latest yaw (heading) value from IMU

//Inputs: None. This function should only be called after mpu.dmpPacketAvailable() returns TRUE

//Outputs:

// returns true if successful, otherwise false

// IMUHdgValDeg updated on success

//Plan:

//Step1: check for overflow and reset the FIFO if it occurs. In this case, wait for new packet

//Step2: read all available packets to get to latest data

//Step3: update IMUHdgValDeg with latest value

//Notes:

// 10/08/19 changed return type to boolean

// 10/08/19 no longer need mpuIntStatus

// 10/21/19 completely rewritten to use Homer's algorithm

// 05/05/20 changed return type to float vs bool.

int flag = GetCurrentFIFOPacket(fifoBuffer, packetSize, MAX_GETPACKET_LOOPS); //get the latest mpu packet

if (flag != 0) //0 = error exit, 1 = normal exit, 2 = recovered from an overflow

{

// display Euler angles in degrees

mpu.dmpGetQuaternion(&q, fifoBuffer);

mpu.dmpGetGravity(&gravity, &q);

mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);

//compute the yaw value

IMUHdgValDeg = ypr[0] * 180 / M_PI;

}

return IMUHdgValDeg;//05/05/20 now returns updated value for use convenience

}

uint8_t GetCurrentFIFOPacket(uint8_t* data, uint8_t length, uint16_t max_loops)

{

mpu.resetFIFO();

delay(1);

//int countloop = 0;

fifoCount = mpu.getFIFOCount();

GetPacketLoopCount = 0;

//Serial1.printf("In GetCurrentFIFOPacket: before loop fifoC = %d\t", fifoCount);

while (fifoCount < packetSize && GetPacketLoopCount < max_loops)

{

GetPacketLoopCount++;

fifoCount = mpu.getFIFOCount();

delay(2);

}

//Serial1.printf("In GetCurrentFIFOPacket: after loop fifoC = %d, loop count = %d\n", fifoCount, GetPacketLoopCount);

if (GetPacketLoopCount >= max_loops)

{

return 0;

}

//if we get to here, there should be exactly one packet in the FIFO

mpu.getFIFOBytes(data, packetSize);

return 1;

}

//void BackupAndTurn90Deg(bool b_ccw, bool b_fwd, int motor_speed)

//{

// //Purpose: Backup 1 second and then turn 90 degrees

// //Provenance: G. Frank Paynter 06/27/2020

// //Inputs:

// // bIsCCW = bool denoting direction for the turn

// // bIsFwd = bool denoting fwd/bkwd direction for the turn

// // motor_speed = int denoting motor speed to use for the maneuver

// //Outputs:

// // Robot backs up 1 sec, then turns 90 deg in the specified direction

// //Plan:

// // Step1: Back up for 1 sec

// // Step2: Turn 90 deg in specified direction

// //Notes:

// // 06/27/20 Replaces BackupAndTurn in all Tracking modes

// //10/13/20 rev to terminate backup at Wall Offset Distance

////Step1: Back up for 1 sec

// BackupSignal(true); //turn backup LEDs ON

// MoveReverse(MOTOR_SPEED_HALF, MOTOR_SPEED_HALF);

// //delay(1000);

// //10/13/20 rev to terminate backup at Wall Offset Distance

// while (frontdistval < WALL_OFFSET_TGTDIST_CM && !bIsStuck)

// {

// if (bTimeForNavUpdate) //wait for next ISR hit

// {

// bTimeForNavUpdate = false;

// Serial.print(F("BackupAndTurn90Deg: ")); Serial1.printf("%lu\t% d\n", millis(), frontdistval);

// }

// BackupSignal(false);//turn them back OFF

// //Serial1.printf("BackupAndTurn90Deg terminated with frontdist = %d\n", frontdistval);

// Serial.print(F("BackupAndTurn90Deg terminated with frontdist = ")); Serial1.printf("%d\n", frontdistval);

// //Step2: Turn 90 deg fwd or backward in specified direction

// SpinTurn(b_ccw, 90); //06/27/20 experiment

//}

#pragma endregion HDG_BASED_TURN_SUPPORT

#pragma region FLASHER_X

//09/20/21 copied from FlasherX

//******************************************************************************

// update_firmware() read hex file and write new firmware to program flash

//******************************************************************************

void update_firmware(Stream* serial, uint32_t buffer_addr, uint32_t buffer_size)

{

static char line[96]; // buffer for hex lines

static char data[32] __attribute__((aligned(8))); // buffer for hex data

hex_info_t hex = { // intel hex info struct

data, 0, 0, 0, // data,addr,num,code

0, 0xFFFFFFFF, 0, // base,min,max,

0, 0 // eof,lines

};

serial->printf("waiting for hex lines...\n");

// read and process intel hex lines until EOF or error

//DEBUG!!

//int line_num = 0;

//DEBUG!!

long int start_msec = 0;

bool bFirstTime = true;

while (!hex.eof) {

read_ascii_line(serial, line, sizeof(line));

if (bFirstTime)

{

start_msec = millis();

bFirstTime = false;

}

//DEBUG!!

//serial->printf("%d: %s\n", line_num, line);

//line_num++;

//DEBUG!!

//10/02/21 gfp added for visual xfer confirmation

if (hex.lines % 10 == 0)

{

digitalWriteFast(LED_BUILTIN, !digitalReadFast(LED_BUILTIN));

}

// reliability of transfer via USB is improved by this printf/flush

if (serial == (Stream*)&Serial)

{

serial->printf("%s\n", line);

serial->flush();

}

if (parse_hex_line((const char*)line, hex.data, &hex.addr, &hex.num, &hex.code) == 0) {

serial->printf("abort - bad hex line %s\n", line);

return;

}

else if (process_hex_record(&hex) != 0) { // error on bad hex code

serial->printf("abort - invalid hex code %d\n", hex.code);

return;

}

else if (hex.code == 0) { // if data record

uint32_t addr = buffer_addr + hex.base + hex.addr - FLASH_BASE_ADDR;

if (hex.max > (FLASH_BASE_ADDR + buffer_size)) {

serial->printf("abort - max address %08lX too large\n", hex.max);

return;

}

else if (!IN_FLASH(buffer_addr)) {

memcpy((void*)addr, (void*)hex.data, hex.num);

}

else if (IN_FLASH(buffer_addr)) {

int error = flash_write_block(addr, hex.data, hex.num);

if (error) {

serial->printf("abort - error %02X in flash_write_block()\n", error);

return;

}

hex.lines++;

}

//serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX)\n",

// hex.lines, hex.max - hex.min, hex.min, hex.max);

serial->printf("\nhex file: %1d lines %1lu bytes (%08lX - %08lX), %lu Msec\n",

hex.lines, hex.max - hex.min, hex.min, hex.max, millis() - start_msec);

// check FSEC value in new code -- abort if incorrect

#if defined(KINETISK) || defined(KINETISL)

uint32_t value = *(uint32_t*)(0x40C + buffer_addr);

if (value == 0xfffff9de) {

serial->printf("new code contains correct FSEC value %08lX\n", value);

}

else {

serial->printf("abort - FSEC value %08lX should be FFFFF9DE\n", value);

return;

}

#endif

// check FLASH_ID in new code - abort if not found

if (check_flash_id(buffer_addr, hex.max - hex.min)) {

serial->printf("new code contains correct target ID %s\n", FLASH_ID);

}

else {

serial->printf("abort - new code missing string %s\n", FLASH_ID);

return;

}

// get user input to write to flash or abort

int user_lines = -1;

while (user_lines != hex.lines && user_lines != 0) {

serial->printf("enter %d to flash or 0 to abort\n", hex.lines);

read_ascii_line(serial, line, sizeof(line));

sscanf(line, "%d", &user_lines);

}

if (user_lines == 0) {

serial->printf("abort - user entered 0 lines\n");

return;

}

// move new program from buffer to flash, free buffer, and reboot

//serial->printf("user entered %d lines\n", user_lines);

flash_move(FLASH_BASE_ADDR, buffer_addr, hex.max - hex.min);

// should not return from flash_move(), but put REBOOT here as reminder

REBOOT;

}

//******************************************************************************

// read_ascii_line() read ascii characters until '\n', '\r', or max bytes

//******************************************************************************

void read_ascii_line(Stream* serial, char* line, int maxbytes)

{

int c = 0, nchar = 0;

while (nchar < maxbytes && !(c == '\n' || c == '\r')) {

if (serial->available()) {

c = serial->read();

line[nchar++] = c;

}

line[nchar - 1] = 0; // null-terminate

}

//******************************************************************************

// process_hex_record() process record and return okay (0) or error (1)

//******************************************************************************

int process_hex_record(hex_info_t* hex)

{

if (hex->code == 0) { // data -- update min/max address so far

if (hex->base + hex->addr + hex->num > hex->max)

hex->max = hex->base + hex->addr + hex->num;

if (hex->base + hex->addr < hex->min)

hex->min = hex->base + hex->addr;

}

else if (hex->code == 1) { // EOF (:flash command not received yet)

hex->eof = 1;

}

else if (hex->code == 2) { // extended segment address (top 16 of 24-bit addr)

hex->base = ((hex->data[0] << 8) | hex->data[1]) << 4;

}

else if (hex->code == 3) { // start segment address (80x86 real mode only)

return 1;

}

else if (hex->code == 4) { // extended linear address (top 16 of 32-bit addr)

hex->base = ((hex->data[0] << 8) | hex->data[1]) << 16;

}

else if (hex->code == 5) { // start linear address (32-bit big endian addr)

hex->base = (hex->data[0] << 24) | (hex->data[1] << 16)

| (hex->data[2] << 8) | (hex->data[3] << 0);

}

else {

return 1;

}

return 0;

}

//******************************************************************************

// Intel Hex record foramt:

// Start code: one character, ASCII colon ':'.

// Byte count: two hex digits, number of bytes (hex digit pairs) in data field.

// Address: four hex digits

// Record type: two hex digits, 00 to 05, defining the meaning of the data field.

// Data: n bytes of data represented by 2n hex digits.

// Checksum: two hex digits, computed value used to verify record has no errors.

// Examples:

// :10 9D30 00 711F0000AD38000005390000F5460000 35

// :04 9D40 00 01480000 D6

// :00 0000 01 FF

//******************************************************************************

/* Intel HEX read/write functions, Paul Stoffregen, paul@ece.orst.edu */

/* This code is in the public domain. Please retain my name and */

/* email address in distributed copies, and let me know about any bugs */

/* I, Paul Stoffregen, give no warranty, expressed or implied for */

/* this software and/or documentation provided, including, without */

/* limitation, warranty of merchantability and fitness for a */

/* particular purpose. */

// type modifications by Jon Zeeff

/* parses a line of intel hex code, stores the data in bytes[] */

/* and the beginning address in addr, and returns a 1 if the */

/* line was valid, or a 0 if an error occured. The variable */

/* num gets the number of bytes that were stored into bytes[] */

#include <stdio.h> // sscanf(), etc.

#include <string.h> // strlen(), etc.

int parse_hex_line(const char* theline, char* bytes,

unsigned int* addr, unsigned int* num, unsigned int* code)

{

unsigned sum, len, cksum;

const char* ptr;

int temp;

*num = 0;

if (theline[0] != ':')

return 0;

if (strlen(theline) < 11)

return 0;

ptr = theline + 1;

if (!sscanf(ptr, "%02x", &len))

return 0;

ptr += 2;

if (strlen(theline) < (11 + (len * 2)))

return 0;

if (!sscanf(ptr, "%04x", (unsigned int*)addr))

return 0;

ptr += 4;

/* Serial1.printf("Line: length=%d Addr=%d\n", len, *addr); */

if (!sscanf(ptr, "%02x", code))

return 0;

ptr += 2;

sum = (len & 255) + ((*addr >> 8) & 255) + (*addr & 255) + (*code & 255);

while (*num != len)

{

if (!sscanf(ptr, "%02x", &temp))

return 0;

bytes[*num] = temp;

ptr += 2;

sum += bytes[*num] & 255;

(*num)++;

if (*num >= 256)

return 0;

}

if (!sscanf(ptr, "%02x", &cksum))

return 0;

if (((sum & 255) + (cksum & 255)) & 255)

return 0; /* checksum error */

return 1;

}

#pragma endregion FLASHER_X

Now that I have turn-rate-based turns working properly, it’s time to turn my attention to the other peripherals – namely the ‘I_total’ and ‘I_run’ 1A169 high-side current sensors, the battery voltage output from the 5V LDO regulator module, and the charge connection status line.

Ported GetTotalAmps(), GetRunningAmps(), IsStillCharging(), IsChargerConnected, and MonitorChargerUntilDone() from FourWD_WallE2_V12.ino.
Ported CHG_SUPP_PARAMETERS into PRE-SETUP
Ported charger support pin init into setup()

After these ports, I got a lot of ‘mySerial was not declared’ errors – not surprising as I needed ‘mySerial’ in the Arduino world to access ‘printf’ formatting, but the Teensy has that feature built-in. After replacing 5 instances of ‘mySerial.’ with ‘Serial1.’, I recompiled – still lots of errors – oh well.

In the Arduino code, I used a function called ‘GetAverageAnalogReading()’ to average A/D readings with a ‘CURRENT_AVERAGE_NUMBER’ parameter. However, in the Teensy world there is a function called

analogReadAveraging(unsigned int num)

1	analogReadAveraging(unsigned int num)

which causes all the ADC channels to average every reading by ‘num’ (where ‘num’ is internally forced to be 0,4,8,16, or 32). So, I can eliminate the ‘GetAverageAnalogReading()’ function entirely for the T3.5, and just use analogRead().

After some minor fumbling around to comment out or bypass non-relevant (to this phase, at least) code, I got the program to compile. Now to test for proper behavior…

Testing for the two 1NA169 current sensors went OK, but I hit a snag when testing the ‘Charger Connected’ line from the charging plug. This line is tied to GND with no jack inserted, and the GND connection is broken when the plug is fully inserted. The pin is initialized for INPUT_PULLUP, meaning the line will be pulled HIGH via the internal pullup resistor when the charging cable is plugged in, and pulled to GND when the plug is removed. My initial pin assignment for this pin was 36/A17, but I discovered this wouldn’t work as some analog inputs didn’t have pullup resistors available. So, I more or less randomly chose pin 28 on the other side for this, only to find out that for no apparent reason, the pullup on pin 28 no longer seemed to exist. The charge connect line indeed measured GND with the plug removed, but only about 0.1-0.2V with the plug engaged, instead of 3.3V as it should. After some screwing around, I finally constructed a very small test program to exercise pins 28-32, whereupon I found that 29-32 operated properly, but 28 refused to behave. I posted about this to the Teensy forum, and another forum member tried my program on one of their T3.5’s and reported that pin 28 behaved properly on their module – rats! In any case, I can move the line to pin 29 no problem, but it’s frustrating to realize that of all the pins I could have picked, I managed to hit the one that misbehaved :(.

25 November 2021 Update (Happy Thanksgiving!)

I’m writing this from the home of my stepson and his family in St. Louis, MO, where we are all gathered for the traditional Turkey Day dinner. Of course I brought my Wall-E3 robot so I could continue to work on bringing it along. While here I managed to get the CHG_CONNECT issue solved, but in the process may have killed another port on the Teensy 3.5. At the moment I have the CHG_CONNECT input assigned to pin 31, and the CHG_CONNECT_LED output assigned to pin 30. Pins 28 and 32 appear to be inactive and might have been casualties in some previous project, or casualties of this one – hard to tell. In any case that all appears to be working now.

The following photo shows the current pin assignments for the T3.5. These may well change before the whole adventure ends, but it’s a good starting point.

29 November 2021 Update:

Here’s my first cut at a system-level schematic for the new Wall-E3 robot:

The above schematic has the same basic layout as for Wall-E2, with the following changes:

The Wixel RF serial extender module has been replaced by the HC-05 Bluetooth module (physically located on the small perf-board module along with the 5V LDO voltage regulator)
The left and right motor drivers are now VNH5019 parts instead of DRV8871
The MPU6050 & IR Detector modules now use their own I2C channel (SDA1/SCL1) instead of everything being serviced on the single I2C channel available on the Mega 2560
The VL53L0X ToF sensor array is still managed by a separate Teensy 3.5, but now is the only device on the primary (SDA0/SCL0) I2C bus

At this point I have verified proper operation for both VNH5019 motor drivers, both 1NA169 inline current sensors, the MPU6050 IMU and the HC-05 Bluetooth module.

The next big milestone is to get the second-deck mounted and verify proper operation of the forward-looking LIDAR and the VL53L0X side and rear ToF distance sensors.

Stay tuned,

Frank

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Paynter's Palace

Wall-E3 Replacing Mega 2560 With Teensy 3.5

Motor Drivers for Wall-E3:

01 November 2021 Update:

04 November 2021 Update:

05 November 2021 Update

10 November 2021 Update:

20 November 2021 Update:

21 November 2021 (an almost palindromic date 21_11_21) Update:

22 November 2021 Update:

25 November 2021 Update (Happy Thanksgiving!)

29 November 2021 Update:

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