Wow, that’s messy! There are two main boards: the first is a little motherboard for the BasicX24 and provides regulated voltage and access to the I/O pins, the second takes four of these digital output pins and provides locomotion. The sensor is just plonked on top and it is connected together with a connection block. All logic voltages are sourced from the regulated supply on the motherboard, while the motor supply is taken from 3x AAA batteries in the toy chassis. Boards are held in place with velcro!