watch-button: added test for epoll module

Author: Jason Kridner

test/watch-button.js

@@ -0,0 +1,24 @@
+var Epoll = require('../node_modules/bonescript/node_modules/epoll').Epoll,
+  fs = require('fs'),
+  valuefd = fs.openSync('/sys/class/gpio/gpio22/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);
+

test/watch-button.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+echo 22 > /sys/class/gpio/export
+echo in > /sys/class/gpio/gpio22/direction
+echo both > /sys/class/gpio/gpio22/edge
+node watch-button