How to use potentiometer data from slave to master Arduino?

Question

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.

• sa_leinad: Why are you using 2 Arduinos? You could do all of this in just one Arduino.
• sa_leinad: Please also improve the formatting of your question.

Answer 1

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() {
 Wire.begin(controllerAddress);
 Wire.onRequest(requestEvent); 
}
void loop() {
 int value = analogRead(controllerPin);
 noInterrupts(); 
 controllerValue = value; 
 interrupts();
}
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.

Cheers!

• Jot: I would assign 'A0' to controllerPin instead of '0', to avoid any confusing with digital pins: const int controllerPin = A0
• Mikael Patel: Nice catch. I will fix that.