Camera error help

Linking back to your original thread on that motor board: Is this like the Sangaboard? - Request Help - OpenFlexure Forum, for anyone who has not seen it.

From that thread, the 5V on the shield going to the motors is connected to the Nano 5V pin, which is connected to the USB 5V. Then back in the Pi, the 5V on the USB is the same as the main board 5V. Although the actual processors run at lower voltages regulated down from the 5V, a Pi seems still to be very susceptible to problems on the main 5V rail.

On the motor board you can isolate the 5V of the Arduino from the board, which should isolate the Pi from your motor 5V supply. The simple way would be to cut-off the 5V pin from the Arduino Nano. That should help. You would need to make sure that any stub left of the pin does not make contact in the socket.