MPR121

MPR121.ino

#include <Wire.h>
#include "Adafruit_MPR121.h"

Adafruit_MPR121 cap = Adafruit_MPR121();

// Keeps track of the last pins touched
// so we know when buttons are 'released'
uint16_t lasttouched = 0;
uint16_t currtouched = 0;

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10);
  }

  // connect to the sensor at the proper address (defined in the documentation)
  if (!cap.begin(0x5A)) {
    Serial.println("MPR121 not found, check wiring?");
    while (1);
  }
  Serial.println("MPR121 found!");
}

void loop() {
  // Get the currently touched pads
  currtouched = cap.touched();
  
  for (uint8_t i=0; i<12; i++) {
    // it if *is* touched and *wasnt* touched before, alert!
    if ((currtouched & bit(i)) && !(lasttouched & bit(i)) ) {
      Serial.print(i); Serial.println(" touched");
    }
    // if it *was* touched and now *isnt*, alert!
    if (!(currtouched & bit(i)) && (lasttouched & bit(i)) ) {
      Serial.print(i); Serial.println(" released");
    }
  }
  lasttouched = currtouched;
}