This project started forming when I got my hands on a broken hoverboard that had been snapped in half. I had plans to put it on something unexpected. That idea became what it is now through some interesting circumstances, such as the battery on my electric scooter becoming unresponsive, and my friend's workplace having a collection of broken shopping carts that they were allowed to help clear. This project looked easy initially, but I ran into a lot of issues that taught me a lot about how STM32 microcontrollers and BLDC motors work.

The more difficult part of this project was securing the motors properly to the shopping cart. These motors produce incredible torque, and need to be held tight enough to keep the shaft of the motor from twisting. I began by widening the holes that were there for the old wheels until they could fit the shaft of the hoverboard wheels. Once they both could fit, I cut a small support bar that interfaces with the flat part of the hoverboard wheel shaft, locking it in place. This has held up so far, but it is not precise and can loosen over time. If I'm ever doing this again, I would machine a proper holder that sandwiches the shaft entirely and bolt that to the bottom of the cart much more securely.

After getting the cart functional, I moved to figuring out how I can use the sideboard to add lights. These sideboards originally were used for balancing the hoverboard using an accelerometer and gyro. I no longer need that function, but the sideboards also handled the lights on the hoverboard. The writer of the firmware for the mainboard also wrote firmware for the sideboard, albeit quite minimal. Looking into it however, I realized that my sideboards are different than the ones shown in the documentation. because of this, the firmware did not work correctly and I had to modify it after I figured out exactly how different these boards were.