onoff/examples/blink-led-promises.js

GPIO access and interrupt detection with Node.js

'use strict';

const Gpio = require('../onoff').Gpio; // Gpio class
const led = new Gpio(17, 'out');       // Export GPIO17 as an output
let stopBlinking = false;

// Toggle the state of the LED connected to GPIO17 every 200ms
const blinkLed = _ => {
  if (stopBlinking) {
    return led.unexport();
  }

  led.read()
    .then(value => led.write(value ^ 1))
    .then(_ => setTimeout(blinkLed, 200))
    .catch(err => console.log(err));
};

blinkLed();

// Stop blinking the LED after 5 seconds
setTimeout(_ => stopBlinking = true, 5000);