MPR121 module - how to know when an electrode is touched?

Hi! It looks like you have to repeatedly 'poll' the module to ask it what keys are pressed, and then you get back a number where each bit represents a key.

I2C1.setup({scl:B6,sda:B7});

var lastKeysPressed = 0;
var mpr = require("MPR121").connect(I2C1, {
   // device is ready
    setInterval(function() {
        var keys = mpr.touched();
        if (keys!=lastKeysPressed) {
          // for each key
          for (var i=0;i<12;i++) {
            var kbit = 1<<i;
            // if it is pressed now, but not before
            if ((keys&kbit) && !(lastKeysPressed&kbit))
              console.log("Touched: " + i);
            // you can also check the opposite to see if it's released
          }
        }
         lastKeysPressed = keys;
    }, 100); // 100ms = 10 times a second
});

This isn't tested, but should work...