42 lines
1.8 KiB
Markdown
42 lines
1.8 KiB
Markdown
# 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)<br />
|
|
- `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
|
|
```lua
|
|
a = 31
|
|
b = 0
|
|
g = 0
|
|
r = 255
|
|
led_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
|
|
```
|