HSB rainbow and final cleanup

README.md

@@ -1,5 +1,5 @@
 # Neopixels bare metal for STM32
-**Bare-metal implementation of WS2812 LED strip for STM32F446RE with PWM and DMA (Direct Memory Access).** During research I found many similar materials about working with WS2812 LED but all of them were for STM32 HAL without explaining the bare-metal concepts (some tutorials have in the title "bare-metal" but eventually misleads potential readers). Doing it from scratch was quite challenging. I guess I'm the first one to publish such thing without unnecessary complexity.
+**Bare-metal implementation of WS2812 LED strip for STM32F446RE with PWM and DMA (Direct Memory Access).** During research I found many similar materials about working with WS2812 LED but all of them were for STM32 HAL without explaining the bare-metal concepts (some tutorials have in the title "bare-metal" but eventually misleads potential readers). Doing it from scratch was quite challenging. I guess I'm the first one to publish such thing without unnecessary complexity. It's in progress so I will appreciate any feedback.
 
 ## Timing constrains from documentation:
 
@@ -79,15 +79,14 @@ I've tested the code with 8 LED strip and 1 meter, 74 LED strip. STM32 operates
 - *Does it make sense to define interrupts for both timer and DMA?*
 - *How to not store DMA buffer as uint32_t to reduce its size (no, changing sizes in DMA won't work).*
 - *Trying to debug PWM signals without an oscilloscope is not possible.*
-- *Fix the HSB convertion algorithm. I tested it in Visual Studio with C++ but there is an issue with conversion using doubles. The saturation and brightness must be set to 100.*
 
 ## List of structs:
 - `Led`: stores the rgb values.
 - `LedStrip`: stores the pointer to led array, its size and strip state.
 
 ## List of functions:
-- `timer_init`: Configure the timer
-- `dma_init`: Configure the DMA.
+- `timer_init()`: Configure the timer
+- `dma_init()`: Configure the DMA.
 - `setRGB(r, g, b)`: Set pixel color as RGB.
 - `setHSB(h, s, b)`: Set pixel color as HSB and convert it to RGB. It's slower than setting directly as RGB. HSB is in range of 360, 100, 100.
 - `createStrip(led_array, size)`: Create the strip struct.

includes/neopixels.h

@@ -1,11 +1,11 @@
 #pragma once
 #include "../STM32F446RE/stm32f4xx.h"
 
-#define TIMER_PRESCALER 2
-#define WS2812_FREQUENCY_800KHZ_TICKS 56
-#define LOGIC_0_TICKS 16
-#define LOGIC_1_TICKS 32
-#define WS2812_RESET_TICKS 2250
+#define TIMER_PRESCALER          2
+#define WS2812_FREQ_800KHZ_TICKS 56
+#define LOGIC_0_TICKS            16
+#define LOGIC_1_TICKS            32
+#define WS2812_RESET_TICKS       2250
 
 typedef struct {
     uint8_t r;
@@ -36,6 +36,4 @@ void clearStrip(LedStrip *strip);
 
 Led setHSB(int h, uint8_t s, uint8_t b);
 Led setRGB(uint8_t r, uint8_t g, uint8_t b);
-Led getHSB(Led *c);
-
-// Led setHSB(double h, double sa, double ba);
+Led getHSB(Led *c);

main.c

@@ -1,9 +1,11 @@
 #include "./STM32F446RE/stm32f4xx.h"
+
+#include <math.h>
 #include "pll.h"
 #include "sysTick.h"
-
 #include "neopixels.h"
-#include <math.h>
+
+#define ENABLE_FPU ((3 << 20) | (3 << 22))
 
 #define LEDS_AMOUNT 74
 
@@ -17,37 +19,27 @@ int main(){
     timer_init();
     dma_init();
 
-    // SCB->CPACR |= ((3 << 10*2)|(3 << 11*2));
-
-    strip = createStrip(leds, LEDS_AMOUNT);
+    SCB->CPACR |= ENABLE_FPU;
 
-    // long prevTime = 0;
     float movement = 0;
 
-    while(1){
-
+    strip = createStrip(leds, LEDS_AMOUNT);
 
-        // for(volatile long i = 0; i < 1000000; i++){
-        //     // __ASM("NOP");
-        // }
+    while(1){
 
-        // long time = getMillis();
+        if(strip.state == STATE_IDLE){
 
-        // if(time - prevTime > 50){
             movement  += 0.05;
-            for(int i = 0; i < strip.size; i++){
-                float sine = (sin((movement + ((i+1)*0.1))) + 1) / 2;
+
+            for(int i = 0; i < strip.size; ++i){
+                float sine = sinf(movement + (i+1) * 0.1 );
+                sine = (sine + 1) / 2;
                 sine *= 360;
-                // uint8_t val = (uint8_t)sine;
-                // if(val == 0) val += 10;
-                strip.led[i] = setHSB(sine, 100,10);
-                // printf()
+                strip.led[i] = setHSB(sine, 100, 20);
             }
-            // strip.led[strip.size-1] = setRGB(0,0,0);
+
             updateStrip(&strip);
-            //movement  += 0.01;
-            // prevTime = time;
-        // }
+        }
     }
 
 }
@@ -65,8 +57,7 @@ void TIM2_IRQHandler(void) {
             strip.state = STATE_RESETTING;
         }
         else if(strip.state == STATE_RESETTING){
-            TIM2->ARR = WS2812_FREQUENCY_800KHZ_TICKS;
-            // TIM2->CR1 &=~ TIM_CR1_CEN;
+            TIM2->ARR = WS2812_FREQ_800KHZ_TICKS;
             strip.state = STATE_IDLE;
         }
     }

makefile

@@ -30,6 +30,7 @@ compile:
 	arm-none-eabi-objcopy -O ihex ./build/$(PROJECT_NAME).elf ./build/$(PROJECT_NAME).hex
 	arm-none-eabi-objcopy -O binary ./build/$(PROJECT_NAME).elf ./build/$(PROJECT_NAME).bin
 
+
 upload:
 	$(STLINK_DIR)/st-flash --reset write ./build/$(PROJECT_NAME).bin 0x8000000
 

sources/neopixels.c

@@ -3,9 +3,9 @@
 #include "sysTick.h"
 #include "neopixels.h"
 
-#define PA5_AF_MODE     (1 << 11)
-#define PA5_AF1         (1 << 20)
-#define CH1_PWM_MODE_1  (6 << 4)
+#define PA5_AF_MODE             (1 << 11)
+#define PA5_AF1                 (1 << 20)
+#define CH1_PWM_MODE_1          (6 << 4)
 
 #define DMA_CHANNEL_3           (3 << 25)
 #define DMA_MEM_TO_PERIPHERAL   (1 << 6)
@@ -19,7 +19,7 @@ void timer_init(){
     GPIOA->AFR[0] |= PA5_AF1;
 
     TIM2->PSC = TIMER_PRESCALER - 1;
-    TIM2->ARR = WS2812_FREQUENCY_800KHZ_TICKS;
+    TIM2->ARR = WS2812_FREQ_800KHZ_TICKS;
     TIM2->CCMR1 = CH1_PWM_MODE_1;
     // TIM2->CCMR1 |= TIM_CCMR1_OC1PE;
     TIM2->DIER |= TIM_DIER_UIE;
@@ -166,88 +166,4 @@ void clearStrip(LedStrip* strip){
     for(int i=0; i<strip->size; ++i){
         strip->led[i] = setRGB(0,0,0);
     }
-}
-
-
-/*
-Led setHSB(double h, double sa, double ba){
-
-    // ba /= 100;
-    // sa /= 100;
-
-    if (h >= 360) h = 0; 
-    double c = ba * sa;
-    double x = c * (1 - fabs(fmod((h / 60), 2) - 1));
-    double m = ba - c;
-    double red =0;
-    double green = 0;
-    double blue = 0;
-    int a = (h / 60);
-    switch (a) {
-        case 0: red = c + m; green = x + m; blue = 0; break;
-        case 1: red = x + m; green = c + m; blue = 0; break;
-        case 2: red = 0; green = c + m; blue = x + m; break;
-        case 3: red = 0; green = x + m; blue = c + m; break;
-        case 4: red = x + m; green = 0; blue = c + m; break;
-        case 5: red = c + m; green = 0; blue = x + m; break;
-    }
-
-
-    // printf("%llf\n", red);
-    // printf("%d, %d, %d\n",round(red ),round(green),round(blue ));
-
-    // uint64_t holder = (uint64_t)red;
-
-    //  printf("%d\n", a);
-
-    // uint8_t buf[8] = {0};
-    // memcpy(buf, &red, 8);
-    //  printf("%lld\n", (uint64_t)red);
-
-
-     Led newColor = {(uint8_t)red, (uint8_t)green, (uint8_t)blue};
-
-    return newColor;
-}
-*/
-
-
-/*
-Led getHSB(Led* color){
-    float H = 0;
-    float S = 0;
-    float B = 0;
-    float delta = 0;
-
-    B = fmax(fmax(color->r, color->g), color->b);
-    delta = B - fmin(fmin(color->r, color->g), color->b);
-
-    if(B == 0){
-        S = 0;
-    }
-    else {
-        S = delta / B;
-    }
-
-    if(S == 0){
-        H = 0;
-    }
-    else{
-
-        if(color->r == B) H = (color->g - color->b) / delta;
-        else if(color->g == B) H = 2 + (color->b = color->r) / delta;
-        else if(color->b == B) H = 4 + (color->r - color->g) / delta;
-
-        H *= 60;
-
-        if(H < 0){
-            H += 360;
-        }
-    }
-
-    B /= 255;
-
-    Led newColor = {H, S, B};
-    return newColor;
-};
-*/
+}