Ned Konz / Mbed 2 deprecated Multi_WS2811_test

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Dependencies:   Multi_WS2811 mbed MMA8451Q

Fork of WS2811 by Heroic Robotics

WS2811.cpp@8:e3249c2b7607, 2012-11-10 (annotated)

Committer:
heroic
Date:
Sat Nov 10 05:58:14 2012 +0000
Revision:
8:e3249c2b7607
Child:
9:dd524af149e6
Initial commit for first cut of WS2811 driver.  These are one-wire style devices, so we do some timing mojo.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
heroic 8:e3249c2b7607 1 // WS2811 driver, kinda.
heroic 8:e3249c2b7607 2 //
heroic 8:e3249c2b7607 3 // Parameterized and modified to use soft SPI.
heroic 8:e3249c2b7607 4 // Jas Strong <jasmine@electronpusher.org>
heroic 8:e3249c2b7607 5 /*****************************************************************************/
heroic 8:e3249c2b7607 6
heroic 8:e3249c2b7607 7 #include "LedStrip.h"
heroic 8:e3249c2b7607 8 #include "WS2811.h"
heroic 8:e3249c2b7607 9
heroic 8:e3249c2b7607 10 WS2811::WS2811(PinName dataPin, PinName clockPin, int n) :
heroic 8:e3249c2b7607 11 dat(dataPin),
heroic 8:e3249c2b7607 12 clk(clockPin) {
heroic 8:e3249c2b7607 13 // Allocate 3 bytes per pixel:
heroic 8:e3249c2b7607 14 numLEDs = n;
heroic 8:e3249c2b7607 15 if ((pixels = (uint8_t *)malloc(numLEDs * 3))) {
heroic 8:e3249c2b7607 16 memset(pixels, 0x00, numLEDs * 3); // Init to RGB 'off' state
heroic 8:e3249c2b7607 17 }
heroic 8:e3249c2b7607 18 // calibrate delay loops for NRZ
heroic 8:e3249c2b7607 19 int i;
heroic 8:e3249c2b7607 20 guardtime.start();
heroic 8:e3249c2b7607 21 for (i=0; i<1000; i++)
heroic 8:e3249c2b7607 22 /* do nothing */;
heroic 8:e3249c2b7607 23 i=guardtime.read_us();
heroic 8:e3249c2b7607 24 printf("ws2811: 1000 iters took %d usec.\n", i);
heroic 8:e3249c2b7607 25 bogocal = (1000 / (i*2.4)); // iterations per bitcell (417 nsec)
heroic 8:e3249c2b7607 26 printf("ws2811: calibrating to %d bogojiffies.\n", bogocal);
heroic 8:e3249c2b7607 27 }
heroic 8:e3249c2b7607 28
heroic 8:e3249c2b7607 29 /*
heroic 8:e3249c2b7607 30 * These chips use a one-wire protocol based on a sort of NRZ signalling- jas.
heroic 8:e3249c2b7607 31 */
heroic 8:e3249c2b7607 32
heroic 8:e3249c2b7607 33 void WS2811::write(uint8_t byte) {
heroic 8:e3249c2b7607 34 for (int i=0; i<8; i++) {
heroic 8:e3249c2b7607 35 if (byte & 0x80)
heroic 8:e3249c2b7607 36 writebit(1);
heroic 8:e3249c2b7607 37 else
heroic 8:e3249c2b7607 38 writebit(0);
heroic 8:e3249c2b7607 39 byte <<= 1;
heroic 8:e3249c2b7607 40 }
heroic 8:e3249c2b7607 41 }
heroic 8:e3249c2b7607 42
heroic 8:e3249c2b7607 43 inline void WS2811::celldelay(void) {
heroic 8:e3249c2b7607 44 for (int i = 0; i<bogocal; i++)
heroic 8:e3249c2b7607 45 /* do nothing */ ;
heroic 8:e3249c2b7607 46 }
heroic 8:e3249c2b7607 47
heroic 8:e3249c2b7607 48 void WS2811::writebit(bool bit) {
heroic 8:e3249c2b7607 49 // first cell is always 1
heroic 8:e3249c2b7607 50 dat = 1;
heroic 8:e3249c2b7607 51 celldelay();
heroic 8:e3249c2b7607 52 if (bit) {
heroic 8:e3249c2b7607 53 celldelay();
heroic 8:e3249c2b7607 54 } else {
heroic 8:e3249c2b7607 55 dat=0;
heroic 8:e3249c2b7607 56 celldelay();
heroic 8:e3249c2b7607 57 }
heroic 8:e3249c2b7607 58 // last cell is always 0
heroic 8:e3249c2b7607 59 dat=0;
heroic 8:e3249c2b7607 60 celldelay();
heroic 8:e3249c2b7607 61 }
heroic 8:e3249c2b7607 62
heroic 8:e3249c2b7607 63 void WS2811::begin(void) {
heroic 8:e3249c2b7607 64 blank();
heroic 8:e3249c2b7607 65 show();
heroic 8:e3249c2b7607 66 }
heroic 8:e3249c2b7607 67
heroic 8:e3249c2b7607 68 uint16_t WS2811::numPixels(void) {
heroic 8:e3249c2b7607 69 return numLEDs;
heroic 8:e3249c2b7607 70 }
heroic 8:e3249c2b7607 71
heroic 8:e3249c2b7607 72 void WS2811::blank(void) {
heroic 8:e3249c2b7607 73 memset(pixels, 0x00, numLEDs * 3);
heroic 8:e3249c2b7607 74 }
heroic 8:e3249c2b7607 75
heroic 8:e3249c2b7607 76 void WS2811::show(void) {
heroic 8:e3249c2b7607 77 uint16_t i, nl3 = numLEDs * 3; // 3 bytes per LED
heroic 8:e3249c2b7607 78 while (guardtime.read_us() < 50)
heroic 8:e3249c2b7607 79 /* spin */;
heroic 8:e3249c2b7607 80 for (i=0; i<nl3; i++ ) {
heroic 8:e3249c2b7607 81 write(pixels[i]);
heroic 8:e3249c2b7607 82 }
heroic 8:e3249c2b7607 83
heroic 8:e3249c2b7607 84 guardtime.reset();
heroic 8:e3249c2b7607 85 }
heroic 8:e3249c2b7607 86
heroic 8:e3249c2b7607 87
heroic 8:e3249c2b7607 88 uint32_t WS2811::total_luminance(void) {
heroic 8:e3249c2b7607 89 uint32_t running_total;
heroic 8:e3249c2b7607 90 running_total = 0;
heroic 8:e3249c2b7607 91 for (int i=0; i<numLEDs*3; i++)
heroic 8:e3249c2b7607 92 running_total += pixels[i];
heroic 8:e3249c2b7607 93 return running_total;
heroic 8:e3249c2b7607 94 }
heroic 8:e3249c2b7607 95
heroic 8:e3249c2b7607 96 // Convert R,G,B to combined 32-bit color
heroic 8:e3249c2b7607 97 uint32_t WS2811::Color(uint8_t r, uint8_t g, uint8_t b) {
heroic 8:e3249c2b7607 98 // Take the lowest 7 bits of each value and append them end to end
heroic 8:e3249c2b7607 99 // We have the top bit set high (its a 'parity-like' bit in the protocol
heroic 8:e3249c2b7607 100 // and must be set!)
heroic 8:e3249c2b7607 101 return ((uint32_t)g << 16) | ((uint32_t)r << 8) | (uint32_t)b;
heroic 8:e3249c2b7607 102 }
heroic 8:e3249c2b7607 103
heroic 8:e3249c2b7607 104 // store the rgb component in our array
heroic 8:e3249c2b7607 105 void WS2811::setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b) {
heroic 8:e3249c2b7607 106 if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
heroic 8:e3249c2b7607 107
heroic 8:e3249c2b7607 108 pixels[n*3 ] = g;
heroic 8:e3249c2b7607 109 pixels[n*3+1] = r;
heroic 8:e3249c2b7607 110 pixels[n*3+2] = b;
heroic 8:e3249c2b7607 111 }
heroic 8:e3249c2b7607 112
heroic 8:e3249c2b7607 113 void WS2811::setPixelR(uint16_t n, uint8_t r) {
heroic 8:e3249c2b7607 114 if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
heroic 8:e3249c2b7607 115
heroic 8:e3249c2b7607 116 pixels[n*3+1] = r;
heroic 8:e3249c2b7607 117 }
heroic 8:e3249c2b7607 118
heroic 8:e3249c2b7607 119 void WS2811::setPixelG(uint16_t n, uint8_t g) {
heroic 8:e3249c2b7607 120 if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
heroic 8:e3249c2b7607 121
heroic 8:e3249c2b7607 122 pixels[n*3] = g;
heroic 8:e3249c2b7607 123 }
heroic 8:e3249c2b7607 124
heroic 8:e3249c2b7607 125 void WS2811::setPixelB(uint16_t n, uint8_t b) {
heroic 8:e3249c2b7607 126 if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
heroic 8:e3249c2b7607 127
heroic 8:e3249c2b7607 128 pixels[n*3+2] = b;
heroic 8:e3249c2b7607 129 }
heroic 8:e3249c2b7607 130
heroic 8:e3249c2b7607 131 void WS2811::setPixelColor(uint16_t n, uint32_t c) {
heroic 8:e3249c2b7607 132 if (n >= numLEDs) return; // '>=' because arrays are 0-indexed
heroic 8:e3249c2b7607 133
heroic 8:e3249c2b7607 134 pixels[n*3 ] = (c >> 16);
heroic 8:e3249c2b7607 135 pixels[n*3+1] = (c >> 8);
heroic 8:e3249c2b7607 136 pixels[n*3+2] = c;
heroic 8:e3249c2b7607 137 }