Files
PiAlive/node_modules/epoll/example/watch-button/watch-button.js
2018-05-16 10:10:23 +02:00

27 lines
775 B
JavaScript

'use strict';
var Epoll = require('../../build/Release/epoll').Epoll,
fs = require('fs'),
valuefd = fs.openSync('/sys/class/gpio/gpio4/value', 'r'),
buffer = new Buffer(1);
// Create a new Epoll. The callback is the interrupt handler.
var poller = new Epoll(function (err, fd, events) {
// Read GPIO value file. Reading also clears the interrupt.
fs.readSync(fd, buffer, 0, 1, 0);
console.log(buffer.toString() === '1' ? 'pressed' : 'released');
});
// Read the GPIO value file before watching to
// prevent an initial unauthentic interrupt.
fs.readSync(valuefd, buffer, 0, 1, 0);
// Start watching for interrupts.
poller.add(valuefd, Epoll.EPOLLPRI);
// Stop watching after 30 seconds.
setTimeout(function () {
poller.remove(valuefd).close();
}, 30000);