rpi-rgb

Implements PWM control of RGB leds for use with Raspberry Pi GPIO in Node.js

How to use

Setup

var RgbChannel = require('rpi-rgb').Channel;
var Colour = require('rpi-rgb').Colour;

var channel1 = new RgbChannel(<red_pin>,<green_pin>,<blue_pin>);

This creates an RGB channel. The pin numbers refer to wiring-pi pin numbers, see http://wiringpi.com/pins for details.

The Colour class

var myColour = new Colour(<red%>, <green%>, <blue%>);

Colours in rpi-rgb are defined as objects with red, green and blue properties between 0 (off) and 100 (full-on).

Methods

.setRgb (myColour, callback)

Immediately sets desired colour, with optional callback function.

.fadeRgb (myColour, time, callback)

Fades to desired colour linearly, over time ms. Optional callback.

.pulseRgb (startColour, endColour, fadeTime, pulseTime)

First, fades to startColour over fadeTime ms as with .fadeRgb, but then fades back and forth between this initial colour and endColour. In this case, pulseTime is the time in ms fading from one colour to the next, e.g. the total period is 2*pulseTime.

.endPulse()

Stops the pulse effect.

.strobeRgb(colour, pulselength, duration, callback)

Creates a stroboscope effect where the output is either switched off, or set to colour. This switch happens every pulselengthms, for a total duration of durationms. Optional callback.

.close()

Shuts down the PWM channel.

Example

This example will start by fading in to blue, then strobing for approximately a second. Then it fades to yellow and starts to pulse red.

var RgbChannel = require('rpi-rgb').Channel;
var Colour = require('rpi-rgb').Colour;

var channel1 = new RgbChannel(23,21,22);

var red = new Colour(100,0,0);
var softRed = new Colour(10,0,0);
var blue = new Colour(0,100,0);
var white = new Colour(100,100,100);
var yellow = new Colour(100,100,0);

// Start by fading to blue.
channel1.fadeRgb(blue, 2000, function() {
  // When that's done, strobe.
  channel1.strobeRgb(white, 18, 1000, function() {
    // After strobing, fade to yellow.
    channel1.fadeRgb(yellow, 700);
  });
});

// After the timeout, all the above is likely done, so start pulsing red.
setTimeout(function(thisobj) { thisobj.pulseRgb(softRed, red, 800, 1500); }, 7000, channel1);