keyboards/cannonkeys/bluepill/ws2812.c

   1 /*
   2  * LEDDriver.c
   3  *
   4  *  Created on: Aug 26, 2013
   5  *      Author: Omri Iluz
   6  */
   7
   8 #include "ws2812.h"
   9 #include "stdlib.h"
  10
  11 #define BYTES_FOR_LED_BYTE 4
  12 #define NB_COLORS 3
  13 #define BYTES_FOR_LED BYTES_FOR_LED_BYTE*NB_COLORS
  14 #define DATA_SIZE BYTES_FOR_LED*NB_LEDS
  15 #define RESET_SIZE 200
  16 #define PREAMBLE_SIZE 4
  17 // Define the spi your LEDs are plugged to here
  18 #define WS2812_SPI SPID2
  19 // Define the number of LEDs you wish to control in your LED strip
  20 #define NB_LEDS RGBLED_NUM
  21
  22  #define LED_SPIRAL 1
  23
  24  static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE];
  25 static uint8_t get_protocol_eq(uint8_t data, int pos);
  26
  27  /*
  28  * This lib is meant to be used asynchronously, thus the colors contained in
  29  * the txbuf will be sent in loop, so that the colors are always the ones you
  30  * put in the table (the user thus have less to worry about)
  31  *
  32  * Since the data are sent via DMA, and the call to spiSend is a blocking one,
  33  * the processor ressources are not used to much, if you see your program being
  34  * too slow, simply add a:
  35  * chThdSleepMilliseconds(x);
  36  * after the spiSend, where you increment x untill you are satisfied with your
  37  * program speed, another trick may be to lower this thread priority : your call
  38  */
  39 static THD_WORKING_AREA(LEDS_THREAD_WA, 128);
  40 static THD_FUNCTION(ledsThread, arg) {
  41   (void) arg;
  42   while(1){
  43     spiSend(&WS2812_SPI, PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE, txbuf);
  44   }
  45 }
  46
  47  static const SPIConfig spicfg = {
  48   false,
  49   NULL,
  50   PORT_WS2812,
  51   PIN_WS2812,
  52   SPI_CR1_BR_1|SPI_CR1_BR_0 // baudrate : fpclk / 8 => 1tick is 0.32us (2.25 MHz)
  53 };
  54
  55  /*
  56  * Function used to initialize the driver.
  57  *
  58  * Starts by shutting off all the LEDs.
  59  * Then gets access on the LED_SPI driver.
  60  * May eventually launch an animation on the LEDs (e.g. a thread setting the
  61  * txbuff values)
  62  */
  63 void leds_init(void){
  64   /* MOSI pin*/
  65   palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_STM32_ALTERNATE_PUSHPULL);
  66   for(int i = 0; i < RESET_SIZE; i++)
  67     txbuf[DATA_SIZE+i] = 0x00;
  68   for (int i=0; i<PREAMBLE_SIZE; i++)
  69     txbuf[i] = 0x00;
  70   spiAcquireBus(&WS2812_SPI);              /* Acquire ownership of the bus.    */
  71   spiStart(&WS2812_SPI, &spicfg);          /* Setup transfer parameters.       */
  72   spiSelect(&WS2812_SPI);                  /* Slave Select assertion.          */
  73   chThdCreateStatic(LEDS_THREAD_WA, sizeof(LEDS_THREAD_WA),NORMALPRIO, ledsThread, NULL);
  74 }
  75
  76  /*
  77  * As the trick here is to use the SPI to send a huge pattern of 0 and 1 to
  78  * the ws2812b protocol, we use this helper function to translate bytes into
  79  * 0s and 1s for the LED (with the appropriate timing).
  80  */
  81 static uint8_t get_protocol_eq(uint8_t data, int pos){
  82   uint8_t eq = 0;
  83   if (data & (1 << (2*(3-pos))))
  84     eq = 0b1110;
  85   else
  86     eq = 0b1000;
  87   if (data & (2 << (2*(3-pos))))
  88     eq += 0b11100000;
  89   else
  90     eq += 0b10000000;
  91   return eq;
  92 }
  93
  94
  95  void WS2812_init(void) {
  96   leds_init();
  97 }
  98
  99  void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds) {
 100   uint8_t i = 0;
 101   while (i < number_of_leds) {
 102     set_led_color_rgb(ledarray[i], i);
 103     i++;
 104   }
 105 }
 106
 107  /*
 108  * If you want to set a LED's color in the RGB color space, simply call this
 109  * function with a hsv_color containing the desired color and the index of the
 110  * led on the LED strip (starting from 0, the first one being the closest the
 111  * first plugged to the board)
 112  *
 113  * Only set the color of the LEDs through the functions given by this API
 114  * (unless you really know what you are doing)
 115  */
 116 void set_led_color_rgb(LED_TYPE color, int pos){
 117   for(int j = 0; j < 4; j++)
 118     txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + j] = get_protocol_eq(color.g, j);
 119   for(int j = 0; j < 4; j++)
 120     txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE+j] = get_protocol_eq(color.r, j);
 121   for(int j = 0; j < 4; j++)
 122     txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE*2+j] = get_protocol_eq(color.b, j);
 123 }
 124
 125  void set_leds_color_rgb(LED_TYPE color){
 126   for(int i = 0; i < NB_LEDS; i++)
 127     set_led_color_rgb(color, i);
 128 }
 129
 130
 131  void ws2812_setleds_rgbw(LED_TYPE *ledarray, uint16_t number_of_leds) {
 132
 133  }