Folks, I’d like to include a list of non-Electric Imp open source libraries and classes in the Dev Center.
If you have any such that you’d like to be included, please PM me or post below names, URLs and license types, and I’ll add them to the list.
Cheers,
Tony
I’d like to have the RGBW NeoPixel library added for the SK6812
`
class SK6812 {
// This class uses SPI to emulate the SK6812s’ one-wire protocol.
// This requires one byte per bit to send data at 7.5 MHz via SPI.
// These consts define the “waveform” to represent a zero or one
// This class was derived from version 2.0.1 of the WS2812 class
// By DHeadrick and has the same license as that class.
static version = [1,0,0];
static ZERO = 0xC0;
static ONE = 0xF8;
static BYTES_PER_PIXEL = 32;
// When instantiated, the SK6812 class will fill this array with blobs to
// represent the waveforms to send the numbers 0 to 255. This allows the
// blobs to be copied in directly, instead of being built for each pixel.
static _bits = array(256, null);
// Private variables passed into the constructor
_spi = null; // imp SPI interface (pre-configured)
_frameSize = null; // number of pixels per frame
_frame = null; // a blob to hold the current frame
// Parameters:
// spi A pre-configured SPI bus (MSB_FIRST, 7500)
// frameSize Number of Pixels per frame
// _draw Whether or not to initially draw a blank frame
constructor(spiBus, frameSize, _draw = true) {
// spiBus must be configured
_spi = spiBus;
_frameSize = frameSize;
_frame = blob(_frameSize * BYTES_PER_PIXEL + 1);
_frame[_frameSize * BYTES_PER_PIXEL] = 0;
// Used in constructing the _bits array
local bytesPerColor = BYTES_PER_PIXEL / 4;
// Fill the _bits array if required
// (Multiple instance of SK6812 will only initialize it once)
if (_bits[0] == null) {
for (local i = 0; i < 256; i++) {
local valblob = blob(bytesPerColor);
valblob.writen((i & 0x80) ? ONE:ZERO,'b');
valblob.writen((i & 0x40) ? ONE:ZERO,'b');
valblob.writen((i & 0x20) ? ONE:ZERO,'b');
valblob.writen((i & 0x10) ? ONE:ZERO,'b');
valblob.writen((i & 0x08) ? ONE:ZERO,'b');
valblob.writen((i & 0x04) ? ONE:ZERO,'b');
valblob.writen((i & 0x02) ? ONE:ZERO,'b');
valblob.writen((i & 0x01) ? ONE:ZERO,'b');
_bits[i] = valblob;
}
}
// Clear the pixel buffer
fill([0,0,0,0]);
// Output the pixels if required
if (_draw) {
this.draw();
}
}
// Configures the SPI Bus
//
// NOTE: If using the configure method, you *must* pass `false` to the
// _draw parameter in the constructor (or else an error will be thrown)
function configure() {
_spi.configure(MSB_FIRST, 7500);
return this;
}
// Sets a pixel in the buffer
// index - the index of the pixel (0 <= index < _frameSize)
// color - [r,g,b,w] (0 <= r,g,b,w <= 255)
//
// NOTE: set(index, color) method is identical to WS2812 v2.0.1 but with an additional color parameter
function set(index, color) {
assert(index >= 0 && index < _frameSize);
assert(color[0] >= 0 && color[0] <= 255);
assert(color[1] >= 0 && color[1] <= 255);
assert(color[2] >= 0 && color[2] <= 255);
assert(color[3] >= 0 && color[3] <= 255);
_frame.seek(index * BYTES_PER_PIXEL);
// Red and green are swapped, so need to swizzle them around
_frame.writeblob(_bits[color[1]]);
_frame.writeblob(_bits[color[0]]);
_frame.writeblob(_bits[color[2]]);
_frame.writeblob(_bits[color[3]]);
return this;
}
// Sets the frame buffer (or a portion of the frame buffer)
// to the specified color, but does not write it to the pixel strip
//
// NOTE: fill([0,0,0,0]) is identical to WS2812 v2.0.1 but with an additional color parameter
function fill(color, start=0, end=null) {
// we can't default to _frameSize -1, so we
// default to null and set to _frameSize - 1
if (end == null) { end = _frameSize - 1; }
// Make sure we're not out of bounds
assert(start >= 0 && start < _frameSize);
assert(end >=0 && end < _frameSize)
assert(color[0] >= 0 && color[0] <= 255);
assert(color[1] >= 0 && color[1] <= 255);
assert(color[2] >= 0 && color[2] <= 255);
assert(color[3] >= 0 && color[3] <= 255);
// Flip start & end if required
if (start > end) {
local temp = start;
start = end;
end = temp;
}
// Create a blob for the color (swapped for GRBW)
local colorBlob = blob(BYTES_PER_PIXEL);
colorBlob.writeblob(_bits[color[1]]);
colorBlob.writeblob(_bits[color[0]]);
colorBlob.writeblob(_bits[color[2]]);
colorBlob.writeblob(_bits[color[3]]);
// Write the color blob to each pixel in the fill
_frame.seek(start*BYTES_PER_PIXEL);
for (local index = start; index <= end; index++) {
_frame.writeblob(colorBlob);
}
return this;
}
// Writes the frame to the pixel strip
//
// NOTE: draw() method is identical to WS2812 v2.0.1 method
function draw() {
_spi.write(_frame);
return this;
}
};
`
Have you got the URL of the GitHub repo you’re hosting this at, @dheadrick.
BTW, if you’re submitting this for EI to offer through #require, it’ll need to be licensed under MIT so we can host it in the EI public repo, but crucially we’ll need to get some hardware to test it out first. Note that this doesn’t prevent you from hosting it on your own repo too.
I modified the existing WS2812 class which is licensed under MIT, so this one should be the same. I have been working with an RGBW pixel strip using the code for a couple of days and have had no issues with the library.
Here is the GitHub link:
Would be nice to have #require for this…