This week, I worked on 4 main tasks:
- Fixing a firmware bug with the internal timer overflowing
- Changing the LED pattern while the system is idling to change colors
- Working on the final presentation
- Working on the final poster
When I was testing with Owen, we ran into a really strange bug where the guitar would zoom through songs in performance mode about 50 minutes after we rebooted. Owen suggested it could be the microseconds timer overflowing. We stored the microseconds value in a signed long (which is 4 bytes on the Teensy4.1). This gave 31 “data” bits (excluding the sign bit). After doing the math,
(2^31 / (60*10^6)) = 36 minutes
I realized overflow was likely the problem. After changing calls to the micros() function with call to millis(), which would overflow at roughly 30*1000 minutes, the system was stable for over an hour.
Since the core functionality of the firmware was finished, I started working on more cosmetic things. I helped Owen change the LED pattern in the WIAT_FOR_START state to oscillate between orange and green. This also served as a “heartbeat” for us to know the system was still active.
Lastly, I worked on documenting the project in the final presentation and poster.