I'm trying to make a game where i can use one Arduino as a controller (the controller is a potentiometer) and the other Arduino sending the signals to the computer. Im trying to figure out communication with two Arduino's so i would like to use two instead of one although using one would be logical and easier. Ive tried looking into I2C but cant seem to figure it out.

  • 1
    Why are you using 2 Arduinos? You could do all of this in just one Arduino. – sa_leinad Dec 7 '16 at 1:55
  • Please also improve the formatting of your question. – sa_leinad Dec 7 '16 at 1:55

Start by reading the potentiometer. Add a Wire request service function and that makes the Slave:

#include <Wire.h>

const uint8_t controllerAddress = 8;
const int controllerPin = A0;
volatile int controllerValue = 0;

void setup() {

void loop() {
  int value = analogRead(controllerPin);
    controllerValue = value;  

void requestEvent() {
  Wire.write((const uint8_t*) &controllerValue, sizeof(controllerValue)); 

This is minor update of the Arduino Wire Master Reader tutorial. The sketch for the Master is left as an exercise.


  • I would assign 'A0' to controllerPin instead of '0', to avoid any confusing with digital pins: const int controllerPin = A0; – Jot Apr 6 '17 at 6:57
  • Nice catch. I will fix that. – Mikael Patel Apr 6 '17 at 18:12

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