"use strict"; const Gpio = require('../onoff').Gpio; const led = new Gpio(17, 'out'); const button = new Gpio(4, 'in', 'rising', {debounceTimeout: 10}); button.watch(function (err, value) { if (err) { throw err; } led.writeSync(led.readSync() ^ 1); }); process.on('SIGINT', function () { led.unexport(); button.unexport(); });