beacon_demo.js

#!/usr/bin/env node
var fs = require('fs');

var gpioDirectory = "/sys/class/gpio";
var pins = {};
pins["seg7Data"]  = { gpio: "145" }; // header pin 10
pins["seg7Clock"] = { gpio: "162" }; // header pin 14
pins["seg7Latch"] = { gpio: "161" }; // header pin 16
pins["ledData"]   = { gpio: "158" }; // header pin 12
pins["ledClock"]  = { gpio: "159" }; // header pin 18

var pinsInit = function() {
 for(var i in pins) {
  console.log("# Enabling " + i);
  write(gpioDirectory + "/export", pins[i].gpio);
  write(gpioDirectory + "/gpio" + pins[i].gpio + "/direction", "out");
  pins[i].value = "" + gpioDirectory + "/gpio" + pins[i].gpio + "/value";
 }
};

var write = function(file, data) {
 console.log("echo " + data + " > " + file);
 fs.writeFile(file, data);
};

var writeList = function(list, delay, callback) {
 var element = list.shift();
 write(element.file, element.data);
 if(list[0]) {
  setTimeout(function () {
   writeList(list, delay, callback);
  }, delay);
 } else {
  callback();
 }
}

pinsInit();

var seg7WriteChar = function(char) {
 //
 //  --A--
 // |     |
 // D     E
 // |     |
 //  --B--
 // |     |
 // F     G
 // |     |
 //  --C--  H
 //
 var chars = {
 //     ABCDEFGH
  '0': "10111110",
  '1': "00001010",
  '2': "11101100",
 }
 var segments = "00000000";
 var list = [];
 if(chars[char]) {
  segments = chars[char];
 }
 list.push({ file: pins.seg7Latch.value, data: '0' });
 for(var i = 0; i < 8; i++) {
  list.push({ file: pins.seg7Clock.value, data: '0' });
  list.push({ file: pins.seg7Data.value, data: segments.substr(i, 1) });
  list.push({ file: pins.seg7Clock.value, data: '1' });
 }
 list.push({ file: pins.seg7Clock.value, data: '0' });
 list.push({ file: pins.seg7Latch.value, data: '1' });
 list.push({ file: pins.seg7Latch.value, data: '0' });
 writeList(list, 100, function() {
  console.log("# Done with character '" + char + "'");
 });
}

var seg7Write = function(string, delay) {
 var nextString = string;
 seg7WriteChar(string, function() {
  setTimeout(function() { seg7Write(nextString, delay) }, delay);
 });
}

//seg7Write("0123456789 ");
seg7WriteChar('0', function() {});

var ledColorWrite = function(color) {
 var done = 0;
 var ledList = [];
 for(var j = 0; j < 3; j++) {
  for(var i = 0; i < 9; i++) {
   var k = color[j] & (1 << i);
   ledList.push( { file: pins.ledData.value, data: (j ? "1" : "0") } );
   ledList.push( { file: pins.ledClock.value, data: "0" } );
   ledList.push( { file: pins.ledClock.value, data: "1" } );
  }
 }
 writeList(ledList, 10, function() {
  console.log("# Done setting LED");
 });
};

//ledColorWrite([0, 0, 0]);
//ledColorWrite([1, 0, 0]);
//ledColorWrite([0, 1, 0]);
//ledColorWrite([0, 0, 1]);
//ledColorWrite([0, 0, 0]);

beacon_demo.txt

# Enabling seg7Data
echo 145 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio145/direction
# Enabling seg7Clock
echo 162 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio162/direction
# Enabling seg7Latch
echo 161 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio161/direction
# Enabling ledData
echo 158 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio158/direction
# Enabling ledClock
echo 159 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio159/direction
echo 0 > /sys/class/gpio/gpio161/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio162/value
echo 0 > /sys/class/gpio/gpio162/value
echo 1 > /sys/class/gpio/gpio161/value
echo 0 > /sys/class/gpio/gpio161/value
# Done with character '0'

debug.txt

root@beagleboard:~# mkdir /debug
root@beagleboard:~# mount -t debugfs none /debug
root@beagleboard:~# cat /debug/gpio

.
.
.

GPIOs 128-159, gpio:                   
 gpio-145 (sysfs               ) out lo
 gpio-147 (HSUSB1 reset        ) out hi
 gpio-149 (beagleboard::usr1   ) out hi
 gpio-150 (beagleboard::usr0   ) out hi
 gpio-158 (sysfs               ) out lo
 gpio-159 (sysfs               ) out lo

.
.
.