[Alan Anderson]

To measure wheel speed, use one of the gear tooth sensors provided in the kit of parts. It's cheap (free), available (you already have two of them), easy to interface (one PWM cable to the RC and a pair of lines for power/ground), and I estimate the required programming is approximately a half dozen lines of code, one in the interrupt service routine, three in the Process_Data_from_Master_uP() routine, and the rest of them in User_Initialization().