/* * LEDDriver.c * * Created on: Aug 26, 2013 * Author: Omri Iluz */ #include "ws2812.h" #include "stdlib.h" #define BYTES_FOR_LED_BYTE 4 #define NB_COLORS 3 #define BYTES_FOR_LED BYTES_FOR_LED_BYTE*NB_COLORS #define DATA_SIZE BYTES_FOR_LED*NB_LEDS #define RESET_SIZE 200 #define PREAMBLE_SIZE 4 // Define the spi your LEDs are plugged to here #define WS2812_SPI SPID2 // Define the number of LEDs you wish to control in your LED strip #define NB_LEDS RGBLED_NUM #define LED_SPIRAL 1 static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE]; static uint8_t get_protocol_eq(uint8_t data, int pos); /* * This lib is meant to be used asynchronously, thus the colors contained in * the txbuf will be sent in loop, so that the colors are always the ones you * put in the table (the user thus have less to worry about) * * Since the data are sent via DMA, and the call to spiSend is a blocking one, * the processor ressources are not used to much, if you see your program being * too slow, simply add a: * chThdSleepMilliseconds(x); * after the spiSend, where you increment x untill you are satisfied with your * program speed, another trick may be to lower this thread priority : your call */ static THD_WORKING_AREA(LEDS_THREAD_WA, 128); static THD_FUNCTION(ledsThread, arg) { (void) arg; while(1){ spiSend(&WS2812_SPI, PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE, txbuf); } } static const SPIConfig spicfg = { NULL, PORT_WS2812, PIN_WS2812, SPI_CR1_BR_1|SPI_CR1_BR_0 // baudrate : fpclk / 8 => 1tick is 0.32us (2.25 MHz) }; /* * Function used to initialize the driver. * * Starts by shutting off all the LEDs. * Then gets access on the LED_SPI driver. * May eventually launch an animation on the LEDs (e.g. a thread setting the * txbuff values) */ void leds_init(void){ /* MOSI pin*/ palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_STM32_ALTERNATE_PUSHPULL); for(int i = 0; i < RESET_SIZE; i++) txbuf[DATA_SIZE+i] = 0x00; for (int i=0; i<PREAMBLE_SIZE; i++) txbuf[i] = 0x00; spiAcquireBus(&WS2812_SPI); /* Acquire ownership of the bus. */ spiStart(&WS2812_SPI, &spicfg); /* Setup transfer parameters. */ spiSelect(&WS2812_SPI); /* Slave Select assertion. */ chThdCreateStatic(LEDS_THREAD_WA, sizeof(LEDS_THREAD_WA),NORMALPRIO, ledsThread, NULL); } /* * As the trick here is to use the SPI to send a huge pattern of 0 and 1 to * the ws2812b protocol, we use this helper function to translate bytes into * 0s and 1s for the LED (with the appropriate timing). */ static uint8_t get_protocol_eq(uint8_t data, int pos){ uint8_t eq = 0; if (data & (1 << (2*(3-pos)))) eq = 0b1110; else eq = 0b1000; if (data & (2 << (2*(3-pos)))) eq += 0b11100000; else eq += 0b10000000; return eq; } void WS2812_init(void) { leds_init(); } void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds) { uint8_t i = 0; while (i < number_of_leds) { set_led_color_rgb(ledarray[i], i); i++; } } /* * If you want to set a LED's color in the RGB color space, simply call this * function with a hsv_color containing the desired color and the index of the * led on the LED strip (starting from 0, the first one being the closest the * first plugged to the board) * * Only set the color of the LEDs through the functions given by this API * (unless you really know what you are doing) */ void set_led_color_rgb(LED_TYPE color, int pos){ for(int j = 0; j < 4; j++) txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + j] = get_protocol_eq(color.g, j); for(int j = 0; j < 4; j++) txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE+j] = get_protocol_eq(color.r, j); for(int j = 0; j < 4; j++) txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE*2+j] = get_protocol_eq(color.b, j); } void set_leds_color_rgb(LED_TYPE color){ for(int i = 0; i < NB_LEDS; i++) set_led_color_rgb(color, i); } void ws2812_setleds_rgbw(LED_TYPE *ledarray, uint16_t number_of_leds) { }