7 #define BYTES_FOR_LED_BYTE 4
9 #define BYTES_FOR_LED BYTES_FOR_LED_BYTE*NB_COLORS
10 #define DATA_SIZE BYTES_FOR_LED*NB_LEDS
11 #define RESET_SIZE 200
12 #define PREAMBLE_SIZE 4
14 // Define the spi your LEDs are plugged to here
15 #define LEDS_SPI SPID2
16 // Define the number of LEDs you wish to control in your LED strip
21 static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE];
22 static uint8_t get_protocol_eq(uint8_t data, int pos);
25 * This lib is meant to be used asynchronously, thus the colors contained in
26 * the txbuf will be sent in loop, so that the colors are always the ones you
27 * put in the table (the user thus have less to worry about)
29 * Since the data are sent via DMA, and the call to spiSend is a blocking one,
30 * the processor ressources are not used to much, if you see your program being
31 * too slow, simply add a:
32 * chThdSleepMilliseconds(x);
33 * after the spiSend, where you increment x untill you are satisfied with your
34 * program speed, another trick may be to lower this thread priority : your call
36 static THD_WORKING_AREA(LEDS_THREAD_WA, 128);
37 static THD_FUNCTION(ledsThread, arg) {
40 spiSend(&LEDS_SPI, PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE, txbuf);
46 * 'Led spiral' is a simple demo in which we put all the leds to the same
47 * color, where this color does all the hsv circle in loop.
48 * If you want to launch the thread that will chage the led colors to the
49 * appropriate value, simply set LED_SPIRAL to 1.
51 static THD_WORKING_AREA(HSVTRANS_WA, 128);
52 static THD_FUNCTION(hsv_transThread, arg){
54 hsv_color color = {0, 255, 127};
58 set_leds_color_hsv(color);
59 chThdSleepMilliseconds(50);
64 static const SPIConfig spicfg = {
68 SPI_CR1_BR_1|SPI_CR1_BR_0 // baudrate : fpclk / 8 => 1tick is 0.32us
72 * Function used to initialize the driver.
74 * Starts by shutting off all the LEDs.
75 * Then gets access on the LED_SPI driver.
76 * May eventually launch an animation on the LEDs (e.g. a thread setting the
80 for(int i = 0; i < RESET_SIZE; i++)
81 txbuf[DATA_SIZE+i] = 0x00;
82 for (int i=0; i<PREAMBLE_SIZE; i++)
84 spiAcquireBus(&LEDS_SPI); /* Acquire ownership of the bus. */
85 spiStart(&LEDS_SPI, &spicfg); /* Setup transfer parameters. */
86 spiSelect(&LEDS_SPI); /* Slave Select assertion. */
87 chThdCreateStatic(LEDS_THREAD_WA, sizeof(LEDS_THREAD_WA),NORMALPRIO, ledsThread, NULL);
89 chThdCreateStatic(HSVTRANS_WA, sizeof(HSVTRANS_WA),
90 NORMALPRIO, hsv_transThread, NULL);
95 * As the trick here is to use the SPI to send a huge pattern of 0 and 1 to
96 * the ws2812b protocol, we use this helper function to translate bytes into
97 * 0s and 1s for the LED (with the appropriate timing).
99 static uint8_t get_protocol_eq(uint8_t data, int pos){
101 if (data & (1 << (2*(3-pos))))
105 if (data & (2 << (2*(3-pos))))
113 * If you want to set a LED's color in the HSV color space, simply call this
114 * function with a hsv_color containing the desired color and the index of the
115 * led on the LED strip (starting from 0, the first one being the closest the
116 * first plugged to the board)
118 * Only set the color of the LEDs through the functions given by this API
119 * (unless you really know what you are doing)
121 void set_led_color_hsv(hsv_color color, int pos){
122 set_led_color_rgb(hsv2rgb(color), pos);
126 * If you want to set a LED's color in the RGB color space, simply call this
127 * function with a hsv_color containing the desired color and the index of the
128 * led on the LED strip (starting from 0, the first one being the closest the
129 * first plugged to the board)
131 * Only set the color of the LEDs through the functions given by this API
132 * (unless you really know what you are doing)
134 void set_led_color_rgb(rgb_color color, int pos){
135 for(int j = 0; j < 4; j++)
136 txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + j] = get_protocol_eq(color.g, j);
137 for(int j = 0; j < 4; j++)
138 txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE+j] = get_protocol_eq(color.r, j);
139 for(int j = 0; j < 4; j++)
140 txbuf[PREAMBLE_SIZE + BYTES_FOR_LED*pos + BYTES_FOR_LED_BYTE*2+j] = get_protocol_eq(color.b, j);
144 * Same as the two above, but sets all the LEDs in the LED strip (HSV)
146 void set_leds_color_hsv(hsv_color color){
147 for(int i = 0; i < NB_LEDS; i++)
148 set_led_color_hsv(color, i);
152 * Same as the two above, but sets all the LEDs in the LED strip (RGB)
154 void set_leds_color_rgb(rgb_color color){
155 for(int i = 0; i < NB_LEDS; i++)
156 set_led_color_rgb(color, i);