Hooloovoo

A superintelligent shade of the color blue.

This is a node.js library to control a APA102 RGB LED strip via SPI with your Raspberry Pi.

Control APA102 programmable LEDs with node.js

Installation

npm install hooloovoo

This module is located on npm as hooloovoo

Initialization

var hooloovoo = require('hooloovoo');
hooloovoo.setup(54); // The number of LEDs 

Parameters:

• the number of LEDs your apa102 strip has (32,60,...)
• (optional) the SPI clock (must be a power of 2). Default is 128

Fill strip with one color

hooloovoo.fill_hex("FF0000");

Set the whole strip the same color with a Hex value.

Parameters:

• A hex value. Between 000000 and FFFFFF

This example sets the all the LEDs in the strip red (FF0000)

hooloovoo.fill_RGB(255,0,0);

Set the whole strip the same color with RGB values.

Parameters:

• red value (0 to 255)
• green value (0 to 255)
• blue value (0 to 255)

This example sets the all the LEDs in the strip red (255,0,0)

hooloovoo.fill_BGR(0,0,255);

Since APA102 LED strips are BRG, there is an option to set them in their native format.

Parameters:

• blue value (0 to 255)
• green value (0 to 255)
• red value (0 to 255)

This example sets the all the LEDs in the strip red (0,0,255)

Set LED color individually

hooloovoo.set_pixel_hex(0,FF0000);  // set LED1 to red

Parameters:

• Select an LED(0 to number of LEDs -1)
• A hex value. Between 000000 and FFFFFF

This example sets LED 0 (first LED) red. (FF0000)

hooloovoo.set_pixel_RGB(0,255,0,0); // set LED1 to red

Parameters:

• Select an LED(0 to number of LEDs -1)
• blue value (0 to 255)
• green value (0 to 255)
• red value (0 to 255)

This example sets LED 0 (first LED) red. (255,0,0)

hooloovoo.set_pixel_BGR(0,0,0,255); // set LED1 to red

Since APA102 LED strips are BRG, there is an option to set them in their native format. Parameters:

• Select an LED(0 to number of LEDs -1)
• blue value (0 to 255)
• green value (0 to 255)
• red value (0 to 255)

This example sets LED 0 (first LED) red. (0,0,255)

Get the RGB value of a pixel

hooloovoo.get_pixel_RGB(0);

Returns an array of the RGB value of the targeted pixel

Parameters:

• the LED you want to know the RGB value of

hooloovoo.get_pixel_RGB(0); // if the LED was red, would return [255,0,0]

Turn off all the LEDs

hooloovoo.clear();

This turns off all the LEDs

Set the SPI clock

hooloovoo.set_clock(128);

Parameters: The SPI clock (must be a power of 2). Default is 128

Send buffer to SPI

hooloovoo.write_strip();

Sends all stored colors to the APA102 strip.
Not normally needed, but exposed for reasons.

Example

var hooloovoo = require('hooloovoo');

// connecting to Raspberry Pi 
hooloovoo.setup(10, 16); // assign number of APA102 LEDs, assign SPI clock
hooloovoo.set_clock(16); // OPTIONAL - Assign SPI clock - same as 2nd value of setup(), so unnecessary if you set it in setup(). Set this individually if you like.

var led_count = 10;

// set all colors to red 
console.log('fill all red');
hooloovoo.fill_RGB(255,0,0);

// after 2 seconds set first 6 LEDs to (red, green, blue, red, green, blue) 
setTimeout(function(){
  console.log("red green blue red green blue");
  // set_pixel_RGB(ledIndex,r,g,b); 
  // ledIndex: 0 = LED1, 1 = LED2, … 
  // red: (0-255), green: (0-255), blue: (0-255)
  hooloovoo.set_pixel_RGB(0,255,0,0);   // set LED1 to red 

  // set_pixel_hex(ledIndex, hexColor); 
  // ledIndex: 0 = LED1, 1 = LED2, … 
  // hexColor: '#FF0000' = red, '#00FF00' = green, ... 
  hooloovoo.set_pixel_hex(1,'00FF00');  // set LED2 to green 
    
  // set_pixel_BGR(ledIndex,b,g,r); 
  // ledIndex: 0 = LED1, 1 = LED2, … 
  // blue: (0-255), green: (0-255), red: (0-255)
  hooloovoo.set_pixel_BGR(2,255,0,0);   // set LED3 to blue 
  
  hooloovoo.set_pixel_hex(3,'FF0000');  // set LED4 to red 
  hooloovoo.set_pixel_hex(4,'00FF00');  // set LED5 to green 
  hooloovoo.set_pixel_hex(5,'0000FF');  // set LED6 to blue 
}, 2000);

When running this example the LED strip will first fill all LEDs with red.
After 2 seconds it sets the color of the first 6 LEDs to (red, green, blue, red, green, blue).

Wiring the Raspberry Pi

Connect your Pi like this to the LED driver:

Raspberry Pi	led driver
GND	GND
5V	input V+
SCLK	input CLK
MOSI	input DIN

I am not responsible for any damages to your hardware. Use this at your own risk.