Posted 06 December 2019

Back in August of this year (4 months ago!) I demonstrated successful wall tracking at an arbitrary offset distance using heading information from a MPU6050 IMU using my little 2-motor robot.   At the time (silly me) I thought the next step was to integrate this new capability back into my larger 4-motor robot and let it loose into the ‘wild’ (my house).  Unfortunately the EMI/RFI problem that I thought I had solved reared its ugly head again, and sent all my beautiful plans right into the crapper :-(.

So, I have spent the last four months once again tracking down and eliminating the issue (really for sure this time – honest!).  As it turned out, the solution was pretty simple, and one that Pololu, the supplier of the metal-geared motors I am using had already described in some detail in this post.  Along the way I learned a lot, and had a lot of fun, but to quote Abraham Lincoln “I feel like the man who was tarred and feathered and ridden out of town on a rail. To the man who asked him how he liked it, he said: ‘If it wasn’t for the honor of the thing, I’d rather walk.” 

In any case, the MPU6050 IMU on my little 2-motor robot with metal-geared motors is now happily churning out yaw values on a polled basis (no interrupt required, thank you!), and I’m back in business with angle-enhanced wall tracking.  Once I got everything working again, I ran some tests on my ‘local field test site’ (AKA my office) to verify that the algorithm still worked and I was still getting good tracking behavior.  I have included some Excel plots and a short video showing the results.

Stay tuned,

Frank