simplify driver to be stateless

src/drivers/wsled.c

@@ -9,10 +9,7 @@ extern "C" {
 #endif
 
 static uint16_t* dmaBuffer;
-static CRGB* wsledPixels; // delete
-static uint32_t resetDelay; // delete
-static size_t dmaBufferSize; // delete
-static WsledType type; // delete
+static size_t dmaBufferSize;
 
 static spi_settings_t spiSettings = {
     .host = SPI2_HOST,
@@ -40,31 +37,30 @@ static const uint16_t timingBits[16] = {
     0x1111, 0x7111, 0x1711, 0x7711, 0x1171, 0x7171, 0x1771, 0x7771,
     0x1117, 0x7117, 0x1717, 0x7717, 0x1177, 0x7177, 0x1777, 0x7777};
 
+static inline uint32_t resetDelay(const wsled_t* dev) {
+    return (dev->type == WS2812B) ? WSLED_12_RESET_TIME : WSLED_15_RESET_TIME;
+}
+
 esp_err_t wsledInit(const wsled_t* dev) {
 
     ESP_LOGI(__FILE__, "Initializing wsled device...");
 
-    type = dev->type;
-    resetDelay = (dev->type == WS2812B) ? WSLED_12_RESET_TIME : WSLED_15_RESET_TIME;
-
     ESP_LOGI(__FILE__, "mallocing the wsledPixel buffer with size %u bytes", sizeof(CRGB) * dev->numLeds);
 
     // 12 bytes for each led + bytes for initial zero and reset state
-    dmaBufferSize = dev->numLeds * 12 + (resetDelay + 1) * 2;
+    dmaBufferSize = dev->numLeds * 12 + (resetDelay(dev) + 1) * 2;
 
     spiSettings.buscfg.mosi_io_num = dev->pin;
     spiSettings.buscfg.max_transfer_sz = dmaBufferSize;
 
     ESP_LOGI(__FILE__, "Initializing spi interface...");
     if (ESP_OK != spi_bus_initialize(spiSettings.host, &spiSettings.buscfg, spiSettings.dma_chan)) {
-        free(wsledPixels);
         ESP_LOGI(__FILE__, "SPI initialization failed");
         return -1;
     }
 
     ESP_LOGI(__FILE__, "Adding spi bus device...");
     if (ESP_OK != spi_bus_add_device(spiSettings.host, &spiSettings.devcfg, &spiSettings.spi)) {
-        free(wsledPixels);
         ESP_LOGI(__FILE__, "Failed to add spi bus device");
         return -1;
     }
@@ -72,14 +68,13 @@ esp_err_t wsledInit(const wsled_t* dev) {
     ESP_LOGI(__FILE__, "heap_caps_malloc() with dmaBufferSize=%u...", dmaBufferSize);
     dmaBuffer = heap_caps_malloc(dmaBufferSize, MALLOC_CAP_DMA);
     if (NULL == dmaBuffer) {
-        free(wsledPixels);
         ESP_LOGI(__FILE__, "Failed to heap_caps_malloc");
         return -1;
     }
     return ESP_OK;
 }
 
-esp_err_t wsledUpdate(const CRGB* pixels, size_t ledCount) {
+esp_err_t wsledUpdate(const wsled_t* dev, const CRGB* pixels, size_t ledCount) {
 
     uint32_t n = 0;
 
@@ -90,8 +85,8 @@ esp_err_t wsledUpdate(const CRGB* pixels, size_t ledCount) {
 
         CRGB currentPixel = pixels[i];
 
-        uint8_t b0 = (type == WS2812B) ? currentPixel.g : currentPixel.r;
-        uint8_t b1 = (type == WS2812B) ? currentPixel.r : currentPixel.g;
+        uint8_t b0 = (dev->type == WS2812B) ? currentPixel.g : currentPixel.r;
+        uint8_t b1 = (dev->type == WS2812B) ? currentPixel.r : currentPixel.g;
         uint8_t b2 = currentPixel.b;
 
         // Green
@@ -109,7 +104,7 @@ esp_err_t wsledUpdate(const CRGB* pixels, size_t ledCount) {
     }
 
     // reset pulse
-    for (int i = 0; i < resetDelay; i++) {
+    for (int i = 0; i < resetDelay(dev); i++) {
         dmaBuffer[n++] = 0;
     }
 

src/drivers/wsled.h

@@ -6,7 +6,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#define WSLED_12_RESET_TIME 30
+#define WSLED_12_RESET_TIME 5
 #define WSLED_15_RESET_TIME 30
 
 #ifdef __cplusplus
@@ -41,7 +41,8 @@ typedef struct {
 // initializes the wsled device provided the device settings 
 esp_err_t wsledInit(const wsled_t* dev);
 
-esp_err_t wsledUpdate(const CRGB* pixels, size_t ledCount);
+// outputs the pixel data in pixels to the device
+esp_err_t wsledUpdate(const wsled_t* dev, const CRGB* pixels, size_t ledCount);
 
 #ifdef __cplusplus
 }

src/tasks/DemoTask.cpp

@@ -7,6 +7,8 @@
 #include "wsled/WsledInterface.hpp"
 #include "shared/pins.h"
 
+#define NUM_LEDS 4
+
 DemoTask::DemoTask() {
 
 }
@@ -20,7 +22,7 @@ void DemoTask::run() {
     SsdInterface ssd(&ssdDev, ssdDigits);
 
     // wsled device
-    wsled_t wsledDev = { gpio_ws2812b, WS2812B, 0 /* fixed */};
+    wsled_t wsledDev = { gpio_ws2812b, WS2812B, NUM_LEDS};
     WsledInterface wsled(&wsledDev);
 
     uint32_t delay = 500; // ms
@@ -31,12 +33,8 @@ void DemoTask::run() {
         digit++;
         if(digit >= 16) digit = 0;
 
-        wsled.fill(CRGB{100, 20, 20});
-        wsled.flush();
-
-        vTaskDelay(delay / portTICK_PERIOD_MS);
-
-        wsled.fill(CRGB{20, 20, 100});
+        CRGB color = (digit % 2) ? CRGB{100, 20, 20} : CRGB{20, 20, 100};
+        wsled.fill(color);
         wsled.flush();
 
         vTaskDelay(delay / portTICK_PERIOD_MS);

src/wsled/WsledInterface.cpp

@@ -1,10 +1,16 @@
 
 #include "WsledInterface.hpp"
 
-WsledInterface::WsledInterface(const wsled_t* device) {
+WsledInterface::WsledInterface(const wsled_t* device) : device_(device), numLeds_(device->numLeds) {
 
     (void)wsledInit(device);
 
+    leds_.resize(numLeds_);
+
+    // turn all leds off
+    (void)fill(CRGB(0, 0, 0));
+    (void)flush();
+
 }
 
 STATUS WsledInterface::writePixel(CRGB pixel, size_t index) {
@@ -23,7 +29,7 @@ STATUS WsledInterface::get(CRGB* pixel, size_t index) {
 
 STATUS WsledInterface::flush() {
 
-    wsledUpdate(leds_, numLeds_);
+    wsledUpdate(device_, leds_.data(), numLeds_);
 
     return OKAY;
 }

src/wsled/WsledInterface.hpp

@@ -2,6 +2,7 @@
 #pragma once
 
 #include "stdint.h"
+#include <vector>
 
 #include "drivers/wsled.h"
 #include "shared/common.h"
@@ -39,9 +40,8 @@ public:
 private:
 
     const wsled_t* device_;
+    size_t numLeds_;
 
-    static constexpr size_t numLeds_ = 4;
-
-    CRGB leds_[numLeds_];
+    std::vector<CRGB> leds_;
 
 };