I assume that you are having problems using the shield. Have you taken into account that the rp2040 runs at 3.3V rather than 5V which the classic Nano runs at ? I strongly suspect that the shield was designed to be used with a classic Nano
Most of the circuit of the shield should be obvious because all it does is to connect power and GPIO pins to one another and the Nano socket. What is it that you want to find out about ?
For convenience this is the shield referred to in the other topic
