first commit

CMakeLists.txt

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+idf_component_register(
+    INCLUDE_DIRS .
+    SRCS esp_ws28xx.c
+    REQUIRES driver
+)

esp_ws28xx.c

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+#include "esp_ws28xx.h"
+
+uint16_t* dma_buffer;
+CRGB* ws28xx_pixels;
+static int led_num, reset_delay, dma_buf_size;
+led_strip_model_t led_model;
+
+static spi_settings_t spi_settings = {
+		.host = SPI2_HOST,
+		.dma_chan = SPI_DMA_CH_AUTO,
+		.buscfg = {
+				.miso_io_num = -1,
+				.sclk_io_num = -1,
+				.quadwp_io_num = -1,
+				.quadhd_io_num = -1,
+		},
+		.devcfg = { .clock_speed_hz = 3.2 * 1000 * 1000, //Clock out at 3.2 MHz
+				.mode = 0, //SPI mode 0
+				.spics_io_num = -1, //CS pin
+				.queue_size = 1,
+				.command_bits = 0,
+				.address_bits = 0,
+				.flags = SPI_DEVICE_TXBIT_LSBFIRST,
+		}
+};
+
+
+void ws28xx_init(int pin, led_strip_model_t model, int led_number) {
+	esp_err_t err;
+	led_num = led_number;
+	led_model = model;
+	dma_buf_size = led_num * 12 + (reset_delay + 1) * 2; //12 bytes for each led + bytes for initial zero and reset state
+	ws28xx_pixels = malloc(sizeof(CRGB) * led_num);
+	spi_settings.buscfg.mosi_io_num = pin;
+	spi_settings.buscfg.max_transfer_sz = dma_buf_size;
+	err = spi_bus_initialize(spi_settings.host, &spi_settings.buscfg, spi_settings.dma_chan);
+	ESP_ERROR_CHECK(err);
+	err = spi_bus_add_device(spi_settings.host, &spi_settings.devcfg, &spi_settings.spi);
+	ESP_ERROR_CHECK(err);
+	reset_delay = (model == WS2812B) ? 3 : 30; //insrease if something breaks. values are less that recommended in datasheets but seem stable
+	dma_buffer = heap_caps_malloc(dma_buf_size, MALLOC_CAP_DMA); // Critical to be DMA memory.
+}
+
+
+void ws28xx_fill_color(CRGB color) {
+	for(int i=0; i < led_num; i++) {
+		ws28xx_pixels[i] = color;
+	}
+}
+
+
+void ws28xx_update() {
+	uint16_t timing_bits[16] = {
+		0x1111,
+		0x7111,
+		0x1711,
+		0x7711,
+		0x1171,
+		0x7171,
+		0x1771,
+		0x7771,
+		0x1117,
+		0x7117,
+		0x1717,
+		0x7717,
+		0x1177,
+		0x7177,
+		0x1777,
+		0x7777
+	};
+	esp_err_t err;
+	int n = 0;
+	memset(dma_buffer, 0, dma_buf_size);
+	
+	dma_buffer[n++] = 0;
+	for (int i = 0; i < led_num; i++) {
+		uint32_t temp = ws28xx_pixels[i].num;// Data you want to write to each LEDs
+		if (led_model == WS2815) {
+			//Red
+			dma_buffer[n++] = timing_bits[0x0f & (temp >>4)];
+			dma_buffer[n++] = timing_bits[0x0f & (temp)];
+
+			//Green
+			dma_buffer[n++] = timing_bits[0x0f & (temp >>12)];
+			dma_buffer[n++] = timing_bits[0x0f & (temp)>>8];
+		} else {
+			//Green
+			dma_buffer[n++] = timing_bits[0x0f & (temp >>12)];
+			dma_buffer[n++] = timing_bits[0x0f & (temp)>>8];
+
+			//Red
+			dma_buffer[n++] = timing_bits[0x0f & (temp >>4)];
+			dma_buffer[n++] = timing_bits[0x0f & (temp)];
+		}
+		//Blue
+		dma_buffer[n++] = timing_bits[0x0f & (temp >>20)];
+		dma_buffer[n++] = timing_bits[0x0f & (temp)>>16];
+	}
+	for (int i = 0; i < reset_delay; i++) dma_buffer[n++] = 0;
+
+	err = spi_device_transmit(spi_settings.spi, &(spi_transaction_t){
+		.length = dma_buf_size * 8,
+		.tx_buffer = dma_buffer,
+	});
+	ESP_ERROR_CHECK(err);
+}

esp_ws28xx.h

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+#ifndef MAIN_ESP_WS28XX_H_
+#define MAIN_ESP_WS28XX_H_
+#include <stdio.h>
+#include <string.h>
+#include "driver/spi_master.h"
+#include "driver/gpio.h"
+
+typedef struct {
+	union {
+		struct {
+            union {
+                uint8_t r;
+                uint8_t red;
+            };
+            union {
+                uint8_t g;
+                uint8_t green;
+            };
+            union {
+                uint8_t b;
+                uint8_t blue;
+            };
+        };
+		uint8_t raw[3];
+		uint32_t num;
+	};
+} CRGB;
+
+typedef struct {
+	spi_host_device_t host;
+	spi_device_handle_t spi;
+	int dma_chan;
+	spi_device_interface_config_t devcfg;
+	spi_bus_config_t buscfg;
+} spi_settings_t;
+
+typedef enum {
+    WS2812B = 0,
+    WS2815,
+} led_strip_model_t;
+
+extern CRGB* ws28xx_pixels;
+
+void ws28xx_init(int pin, led_strip_model_t model, int led_number);
+void ws28xx_fill_color(CRGB color);
+void ws28xx_update();
+
+
+#endif /* MAIN_ESP_WS28XX_H_ */

idf_component.yml

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+version: "1.0.0"
+description: SPI DMA led strip driver for WS28xx. Currently supports WS2812b and WS2815
+
+