1import * as gpio from 'gpio';
2
3var led = gpio.open({
4  id: 'led',
5  success: function() {
6      console.log('gpio: open led success')
7  },
8  fail: function() {
9      console.log('gpio: open led failed')
10  }
11});
12
13var vol = 0;
14setInterval(function() {
15    vol = 1 - vol;
16	led.writeValue(vol);
17	console.log('gpio: led set value ' + vol);
18}, 2000);
19
20
21