# APA102 Module | Since | Origin / Contributor | Maintainer | Source | | :----- | :-------------------- | :---------- | :------ | | 2016-01-26 | [Robert Foss](https://github.com/robertfoss)| [Robert Foss](https://github.com/robertfoss)| [apa102.c](../../app/modules/apa102.c)| This module provides Lua access to [APA102 RGB LEDs](https://youtu.be/UYvC-hukz-0) which are similar in function to the common [WS2812](ws2812) addressable LEDs. > DotStar LEDs are 5050-sized LEDs with an embedded micro controller inside the LED. You can set the color/brightness of each LED to 24-bit color (8 bits each red green and blue). Each LED acts like a shift register, reading incoming color data on the input pins, and then shifting the previous color data out on the output pin. By sending a long string of data, you can control an infinite number of LEDs, just tack on more or cut off unwanted LEDs at the end. source: [Adafruit](https://www.adafruit.com/products/2343) ## apa102.write() Send ABGR data in 8 bits to a APA102 chain. #### Syntax `apa102.write(data_pin, clock_pin, string)` #### Parameters - `data_pin` any GPIO pin 0, 1, 2, ... - `clock_pin` any GPIO pin 0, 1, 2, ... - `string` payload to be sent to one or more APA102 LEDs. It should be composed from a ABGR quadruplet per element. - `A1` the first pixel's Intensity channel (0-31) - `B1` the first pixel's Blue channel (0-255)
- `G1` the first pixel's Green channel (0-255) - `R1` the first pixel's Red channel (0-255) ... You can connect a lot of APA102 ... - `A2`, `B2`, `G2`, `R2` are the next APA102s Intensity, Blue, Green and Red channel parameters #### Returns `nil` #### Example 1 ```lua a = 31 b = 0 g = 0 r = 255 leds_abgr = string.char(a, b, g, r, a, b, g, r) apa102.write(2, 3, leds_abgr) -- turn two APA102s to red, connected to data_pin 2 and clock_pin 3 ``` #### Example 2 ```lua -- set the first 30 leds to red apa102.write(2, 3, string.char(31, 255, 0, 0):rep(30)) ```