NPM onoff with closure for Watch

gistfile1.txt

/**
 * Simple code to have notifications (interrupts) when the signal to the input pins change.
 * 
 */
const Gpio = require('onoff').Gpio;

var sensorPins = [27,22,5,6,13,26,23,18];
var sensors = [];

// Loop through each configured sensor and create the onoff
for (var i=0; i<sensorPins.length; i++) {
  // Use a closure to identify the pin in the callback
  function createSensor(pin) {
    var sensor = new Gpio(pin,'in','rising', {debounceTimeout:10})

    sensor.watch(function (err, value) {
      if (err) {
        throw err;
      }

      console.log("Pin "+pin+":"+value);
    });
  };
  var newSensor = createSensor(sensorPins[i]);

  sensors.push(newSensor);
}

/**
 * Ctrl-c handler
 */
process.on('SIGINT', function () {
  for (var i=0; i<sensorPins.length; i++) {
    sensors[i].unexport();
  }
});