I have the following test-circuit and I was wondering if I should connect both arduinos to ground or if it’s sufficient to just use one. Now I only put the arduino UNO ground on the breadboard. Should I also connect the breadboard ground to a DUE ground pin?
Information about the circuit:
I am outputting a square wave signal from pin nine of the uno (red wire). The signal gets to a voltage divider of 3x560ohm resistors. I get the signal after the first resistor (3.32V) and detect it on pin51 of the due. The due calculates the frequency and outputs a DAC voltage according to the frequency [0-2MHz] which lights up the LED.