Circuit is like here https://www.arduino.cc/en/tutorial/potentiometer
#include <Wire.h>
int status_module = 0;
#define potmeter A3
void setup() {
Serial.begin(9600);
Wire.begin(1);
Wire.onRequest(requestEvent);
}
void loop() {
int pot_waarde = analogRead(potmeter);
Serial.println (pot_waarde);
}
//SUB-ROUTINES
void requestEvent() {
Wire.write(status_module);
}