Reverse engineering my e-bike’s head unit and motor controller to build a custom head unit out of a Raspberry Pi with oled touch screen (head unit will also be

Reverse engineering my e-bike’s head unit and motor controller to build a custom head unit out of a Raspberry Pi with oled touch screen (head unit will also be used to control LED patterns on the bike). Used a logic analyzer to work out the protocol between the head unit and the motor controller (uart at 9600) and used a ESP32 to man in the middle the protocol. Currently reverse engineering the meaning of the bytes in the packets sent between the units. First attempt was taking apart the head unit and attaching a debugger to the exposed serial debug interface (Cortex M0) chip, but looks like the manufacturer had disabled flash reading by setting the flash security bit.