This is a npm module for connecting a Raspbery Pi to Neopixel strips. It uses the library from jgarff https://github.com/jgarff/rpi_ws281x.
$ npm install rpi-ws281x --save
var ws281x = require('rpi-ws281x');
// One time initialization
ws281x.configure({leds:16});
// Create my pixels
var pixels = new Uint32Array(16);
// Render pixels to the Neopixel strip
ws281x.render(pixels);
This module is simple and only has three methods configure(), render() and reset().
var ws281x = require('rpi-ws281x');
class Example {
constructor() {
this.config = {};
// Number of leds in my strip
this.config.leds = 169;
// Use DMA 10 (default 10)
this.config.dma = 10;
// Set full brightness, a value from 0 to 255 (default 255)
this.config.brightness = 255;
// Set the GPIO number to communicate with the Neopixel strip (default 18)
this.config.gpio = 18;
// The RGB sequence may vary on some strips. Valid values
// are "rgb", "rbg", "grb", "gbr", "bgr", "brg".
// Default is "rgb".
// RGBW strips are not currently supported.
this.config.stripType = 'grb';
// Configure ws281x
ws281x.configure(this.config);
}
run() {
// Create a pixel array matching the number of leds.
// This must be an instance of Uint32Array.
var pixels = new Uint32Array(this.config.leds);
// Create a fill color with red/green/blue.
var red = 255, green = 0, blue = 0;
var color = (red << 16) | (green << 8)| blue;
for (var i = 0; i < this.config.leds; i++)
pixels[i] = color;
// Render to strip
ws281x.render(pixels);
}
};
var example = new Example();
example.run();
var ws281x = require('rpi-ws281x');
class Example {
constructor() {
// Current pixel position
this.offset = 0;
// Set my Neopixel configuration
this.config = {leds:169};
// Configure ws281x
ws281x.configure(this.config);
}
loop() {
var pixels = new Uint32Array(this.config.leds);
// Set a specific pixel
pixels[this.offset] = 0xFF0000;
// Move on to next
this.offset = (this.offset + 1) % this.config.leds;
// Render to strip
ws281x.render(pixels);
}
run() {
// Loop every 100 ms
setInterval(this.loop.bind(this), 100);
}
};
var example = new Example();
example.run();
var ws281x = require('rpi-ws281x');
class Example {
constructor() {
// Current pixel position
this.offset = 0;
// Set my Neopixel configuration
this.config = {};
// By setting width and height instead of number of leds
// you may use named pixel mappings.
// Currently "matrix" and "alternating-matrix" are
// supported. You may also set the "map" property
// to a custom Uint32Array to define your own map.
this.config.width = 13;
this.config.height = 13;
this.config.map = 'alternating-matrix';
// Configure ws281x
ws281x.configure(this.config);
}
loop() {
var leds = this.config.width * this.config.height;
var pixels = new Uint32Array(leds);
// Set a specific pixel
pixels[this.offset] = 0xFF0000;
// Move on to next
this.offset = (this.offset + 1) % leds;
// Render to strip
ws281x.render(pixels);
}
run() {
// Loop every 100 ms
setInterval(this.loop.bind(this), 100);
}
};
var example = new Example();
example.run();