##About

Node.js bindings to wiringPi for Raspberry Pi 2 and the latest WiringPi development sources.

Based on the awesome work of:

1. Eugene Ware
2. Soarez

Motivation

I wanted to create a simple LED animation with a node.js based Javascript. For certain reasons, the performance impact of the GPIO related code should be as small as possible. Thus calls to external command line tools aren't an option.

Currently (July 2015), there are a handful libraries out there, which are wrappers for the wiringPi library. My fokus went on 'wiring-pi' libs, because they seemed to me matured enough. But none of the blink.js examples worked on my Pi 2 - I couldn't set any GPIO pins to low nor high. I figured out that wiring-pi used out-dated wiringPi code and latest development in wiringPi fixed certain RaspPi2 issues.

So I rolled up my sleeves up and started the pebbly way to patch wiring-pi.

... mission accomplished :-)

Install & Usage

You may simply use npm and point it to this fork on Github:

npm install nitram509/wiring-pi --save

For more details, see https://github.com/eugeneware/wiring-pi or https://github.com/Soarez/node-wiring-pi

Known Issues

In order to make the wrapper code compile, I had to make some decisions and changes. Mostly I used to delete code, when the compiler complained. This speeded up my monkey patching and saved me time from investigating a better migration strategy. Be aware, that some features aren't supported in this fork.

• dropped devlib/tcs34725 support
• dropped extensions/pca9685 support
• dropped pulseIn() method
• only works with node.js 0.10.x (and not compatible with 0.12.x, because of V8 API change)

LED animation platine & layout

http://fritzing.org/projects/raspberry-pi-server-load-indicator-5x-led

LED animation example source

var wpi = require('/home/pi/wiring-pi/lib/exports.js');
wpi.wiringPiSetup()

// for pinout, see http://pi.gadgetoid.com/pinout
var LED_PINS_WiringPi = [8, 9, 7, 0, 1];

for (var i=0; i < LED_PINS_WiringPi.length; i++) {
  wpi.pinMode(LED_PINS_WiringPi[i], wpi.OUTPUT);
}

var values = [1,1,1,1,1];
var index = 0;

setInterval(function() {
  // previous LED
  var pin = LED_PINS_WiringPi[index];
  values[index] = +!values[index];
  wpi.digitalWrite(pin, values[index]);

  // next LED
  index = (index + 1) % LED_PINS_WiringPi.length;
  pin = LED_PINS_WiringPi[index];
  wpi.digitalWrite(pin, values[index]);
}, 50);