Added single colour mode to WS2811 driver for RAM savings.

src/main/drivers/light_ws2811strip.c

@@ -57,8 +57,9 @@ volatile uint8_t ws2811LedDataTransferInProgress = 0;
 uint16_t BIT_COMPARE_1 = 0;
 uint16_t BIT_COMPARE_0 = 0;
 
-static hsvColor_t ledColorBuffer[WS2811_LED_STRIP_LENGTH];
+static hsvColor_t ledColorBuffer[WS2811_DATA_BUFFER_SIZE];
 
+#if !defined(USE_WS2811_SINGLE_COLOUR)
 void setLedHsv(uint16_t index, const hsvColor_t *color)
 {
     ledColorBuffer[index] = *color;
@@ -78,19 +79,20 @@ void scaleLedValue(uint16_t index, const uint8_t scalePercent)
 {
     ledColorBuffer[index].v = ((uint16_t)ledColorBuffer[index].v * scalePercent / 100);
 }
+#endif
 
 void setStripColor(const hsvColor_t *color)
 {
     uint16_t index;
-    for (index = 0; index < WS2811_LED_STRIP_LENGTH; index++) {
+    for (index = 0; index < WS2811_DATA_BUFFER_SIZE; index++) {
-        setLedHsv(index, color);
+        ledColorBuffer[index] = *color;
     }
 }
 
 void setStripColors(const hsvColor_t *colors)
 {
     uint16_t index;
-    for (index = 0; index < WS2811_LED_STRIP_LENGTH; index++) {
+    for (index = 0; index < WS2811_DATA_BUFFER_SIZE; index++) {
         setLedHsv(index, colors++);
     }
 }
@@ -114,10 +116,7 @@ bool isWS2811LedStripReady(void)
 STATIC_UNIT_TESTED uint16_t dmaBufferOffset;
 static int16_t ledIndex;
 
-#define USE_FAST_DMA_BUFFER_IMPL
+STATIC_UNIT_TESTED void updateLEDDMABuffer(ledStripFormatRGB_e ledFormat, rgbColor24bpp_t *color)
-#ifdef USE_FAST_DMA_BUFFER_IMPL
-
-STATIC_UNIT_TESTED void fastUpdateLEDDMABuffer(ledStripFormatRGB_e ledFormat, rgbColor24bpp_t *color)
 {
     uint32_t packed_colour;
 
@@ -136,25 +135,6 @@ STATIC_UNIT_TESTED void fastUpdateLEDDMABuffer(ledStripFormatRGB_e ledFormat, rg
         ledStripDMABuffer[dmaBufferOffset++] = (packed_colour & (1 << index)) ? BIT_COMPARE_1 : BIT_COMPARE_0;
     }
 }
-#else
-STATIC_UNIT_TESTED void updateLEDDMABuffer(uint8_t componentValue)
-{
-    uint8_t bitIndex;
-
-    for (bitIndex = 0; bitIndex < 8; bitIndex++)
-    {
-        if ((componentValue << bitIndex) & 0x80 )    // data sent MSB first, j = 0 is MSB j = 7 is LSB
-        {
-            ledStripDMABuffer[dmaBufferOffset] = BIT_COMPARE_1;
-        }
-        else
-        {
-            ledStripDMABuffer[dmaBufferOffset] = BIT_COMPARE_0;   // compare value for logical 0
-        }
-        dmaBufferOffset++;
-    }
-}
-#endif
 
 /*
  * This method is non-blocking unless an existing LED update is in progress.
@@ -174,28 +154,11 @@ void ws2811UpdateStrip(ledStripFormatRGB_e ledFormat)
 
     // fill transmit buffer with correct compare values to achieve
     // correct pulse widths according to color values
-    while (ledIndex < WS2811_LED_STRIP_LENGTH)
+    while (ledIndex < WS2811_DATA_BUFFER_SIZE)
     {
         rgb24 = hsvToRgb24(&ledColorBuffer[ledIndex]);
 
-#ifdef USE_FAST_DMA_BUFFER_IMPL
+        updateLEDDMABuffer(ledFormat, rgb24);
-        fastUpdateLEDDMABuffer(ledFormat, rgb24);
-#else
-        switch (ledFormat) {
-            case LED_RGB: // WS2811 drivers use RGB format
-            updateLEDDMABuffer(rgb24->rgb.r);
-            updateLEDDMABuffer(rgb24->rgb.g);
-            break;
-
-        case LED_GRB: // WS2812 drivers use GRB format
-        default:
-            updateLEDDMABuffer(rgb24->rgb.g);
-            updateLEDDMABuffer(rgb24->rgb.r);
-            break;
-        }
-
-        updateLEDDMABuffer(rgb24->rgb.b);
-#endif
 
         ledIndex++;
     }

src/main/drivers/light_ws2811strip.h

@@ -20,16 +20,26 @@
 
 #pragma once
 
+#include "platform.h"
+
 #include "drivers/io_types.h"
 
 #define WS2811_LED_STRIP_LENGTH    32
+
 #define WS2811_BITS_PER_LED        24
+
+#if defined(USE_WS2811_SINGLE_COLOUR)
+#define WS2811_DATA_BUFFER_SIZE    1
+#define WS2811_DMA_BUFFER_SIZE     (WS2811_DATA_BUFFER_SIZE * WS2811_BITS_PER_LED)
+// Do 2 extra iterations of the DMA transfer with the ouptut set to low to generate the > 50us delay.
+#define WS2811_DELAY_ITERATIONS    2
+#else
+#define WS2811_DATA_BUFFER_SIZE    WS2811_LED_STRIP_LENGTH
 // for 50us delay
 #define WS2811_DELAY_BUFFER_LENGTH 42
-
-#define WS2811_DATA_BUFFER_SIZE    (WS2811_BITS_PER_LED * WS2811_LED_STRIP_LENGTH)
 // number of bytes needed is #LEDs * 24 bytes + 42 trailing bytes)
-#define WS2811_DMA_BUFFER_SIZE     (WS2811_DATA_BUFFER_SIZE + WS2811_DELAY_BUFFER_LENGTH)
+#define WS2811_DMA_BUFFER_SIZE     (WS2811_DATA_BUFFER_SIZE * WS2811_BITS_PER_LED + WS2811_DELAY_BUFFER_LENGTH)
+#endif
 
 #define WS2811_TIMER_MHZ           48
 #define WS2811_CARRIER_HZ          800000

src/main/drivers/light_ws2811strip_stdperiph.c

@@ -20,6 +20,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "platform.h"
 
@@ -50,9 +51,26 @@ static TIM_TypeDef *timer = NULL;
 
 static void WS2811_DMA_IRQHandler(dmaChannelDescriptor_t *descriptor)
 {
+#if defined(USE_WS2811_SINGLE_COLOUR)
+    static uint32_t counter = 0;
+#endif
+
     if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TCIF)) {
+#if defined(USE_WS2811_SINGLE_COLOUR)
+        counter++;
+        if (counter == WS2811_LED_STRIP_LENGTH) {
+            // Output low for 50us delay
+            memset(ledStripDMABuffer, 0, sizeof(ledStripDMABuffer));
+        } else if (counter == (WS2811_LED_STRIP_LENGTH + WS2811_DELAY_ITERATIONS)) {
+            counter = 0;
+            ws2811LedDataTransferInProgress = 0;
+            DMA_Cmd(descriptor->ref, DISABLE);
+        }
+#else
         ws2811LedDataTransferInProgress = 0;
         DMA_Cmd(descriptor->ref, DISABLE);
+#endif
+
         DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
     }
 }
@@ -162,7 +180,7 @@ void ws2811LedStripHardwareInit(ioTag_t ioTag)
     DMA_InitStructure.DMA_Priority = DMA_Priority_High;
     DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
 #endif
-    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
+    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
 
     DMA_Init(dmaRef, &DMA_InitStructure);
     TIM_DMACmd(timer, timerDmaSource(timerHardware->channel), ENABLE);

src/main/io/ledstrip.c

@@ -94,10 +94,6 @@ static uint8_t previousProfileColorIndex = COLOR_UNDEFINED;
 #define BEACON_FAILSAFE_PERIOD_US 250      // 2Hz
 #define BEACON_FAILSAFE_ON_PERCENT 50      // 50% duty cycle
 
-#if LED_MAX_STRIP_LENGTH > WS2811_LED_STRIP_LENGTH
-# error "Led strip length must match driver"
-#endif
-
 const hsvColor_t hsv[] = {
     //                        H    S    V
     [COLOR_BLACK] =        {  0,   0,   0},
@@ -140,6 +136,11 @@ void pgResetFn_ledStripConfig(ledStripConfig_t *ledStripConfig)
 }
 
 #ifdef USE_LED_STRIP_STATUS_MODE
+
+#if LED_MAX_STRIP_LENGTH > WS2811_LED_STRIP_LENGTH
+# error "Led strip length must match driver"
+#endif
+
 const hsvColor_t *colors;
 const modeColorIndexes_t *modeColors;
 specialColorIndexes_t specialColors;

src/main/target/common_post.h

@@ -244,6 +244,10 @@
 #undef USE_LED_STRIP_STATUS_MODE
 #endif
 
+#if defined(USE_LED_STRIP) && !defined(USE_LED_STRIP_STATUS_MODE)
+#define USE_WS2811_SINGLE_COLOUR
+#endif
+
 #if defined(SIMULATOR_BUILD) || defined(UNIT_TEST)
 // This feature uses 'arm_math.h', which does not exist for x86.
 #undef USE_GYRO_DATA_ANALYSE

src/test/unit/ws2811_unittest.cc

@@ -33,8 +33,7 @@ extern "C" {
 extern "C" {
 STATIC_UNIT_TESTED extern uint16_t dmaBufferOffset;
 
-STATIC_UNIT_TESTED void fastUpdateLEDDMABuffer(rgbColor24bpp_t *color);
+STATIC_UNIT_TESTED void updateLEDDMABuffer(rgbColor24bpp_t *color);
-STATIC_UNIT_TESTED void updateLEDDMABuffer(uint8_t componentValue);
 }
 
 TEST(WS2812, updateDMABuffer) {
@@ -45,13 +44,7 @@ TEST(WS2812, updateDMABuffer) {
     dmaBufferOffset = 0;
 
     // when
-#if 0
+    updateLEDDMABuffer(&color1);
-    updateLEDDMABuffer(color1.rgb.g);
-    updateLEDDMABuffer(color1.rgb.r);
-    updateLEDDMABuffer(color1.rgb.b);
-#else
-    fastUpdateLEDDMABuffer(&color1);
-#endif
 
     // then
     EXPECT_EQ(24, dmaBufferOffset);