Diff: neopixel.cpp

Revision:

3:a9b4b2565a23

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/neopixel.cpp	Sun Mar 27 04:51:16 2022 +0000
@@ -0,0 +1,147 @@
+#include "mbed.h"
+#include "neopixel.h"
+
+#if defined(TARGET_NUCLEO_L432KC)
+
+#define PIXEL_WAIT_1_ (6)
+#define PIXEL_WAIT_2_ (2)
+#define PIXEL_WAIT_3_ (3)
+#define PIXEL_WAIT_4_ (5)
+
+#elif defined(TARGET_NUCLEO_F446RE)
+
+#define PIXEL_WAIT_1_ (9)
+#define PIXEL_WAIT_2_ (5)
+#define PIXEL_WAIT_3_ (4)
+#define PIXEL_WAIT_4_ (9)
+
+#else
+#error This board is not supported
+#endif
+
+NeoPixelOut::NeoPixelOut(PinName pin, int num) : DigitalOut(pin)
+{
+    normalize = false;
+    global_scale = 1.0f;
+    num_pixels_ = num;
+    strip_.resize(num);
+}
+
+// The timing should be approximately 800ns/300ns, 300ns/800ns
+inline void NeoPixelOut::byte(register uint32_t byte)
+{        
+    for (int i = 0; i < 8; i++) {
+        gpio_write(&gpio, 1);
+        
+        // duty cycle determines bit value
+        if (byte & 0x80) {
+            // one
+            for(int j = 0; j < PIXEL_WAIT_1_; j++) asm("NOP");//6 9
+            
+            gpio_write(&gpio, 0);
+            for(int j = 0; j < PIXEL_WAIT_2_; j++) asm("NOP");//2 5
+        }
+        else {
+            // zero
+            for(int j = 0; j < PIXEL_WAIT_3_; j++) asm("NOP");//3 4
+            
+            gpio_write(&gpio, 0);
+            for(int j = 0; j < PIXEL_WAIT_4_; j++) asm("NOP");//5 9
+        }
+
+        byte = byte << 1; // shift to next bit
+    }
+    
+}
+
+void NeoPixelOut::setPixelColor(uint32_t i,uint8_t r,uint8_t g,uint8_t b){
+    setPixelColor(i,color(r, g, b));
+}
+
+void NeoPixelOut::setPixelColor(uint32_t i,uint32_t color){
+    if(i < num_pixels_){
+        buf_.hex = color;
+        if (normalize) {
+            float sum = buf_.r+buf_.g+buf_.b;
+            if(sum != 0){
+                float scale = 255.0f/sum;
+                buf_.r *= scale;
+                buf_.g *= scale;
+                buf_.b *= scale;
+            }
+        }
+        buf_.r *= global_scale;
+        buf_.g *= global_scale;
+        buf_.b *= global_scale;
+        
+        strip_[i] = buf_;
+    }
+}
+
+void NeoPixelOut::show(bool flipwait){
+    // Disable interrupts in the critical section
+    __disable_irq();
+    
+    for (int i = 0; i < num_pixels_; i++) {
+        // Black magic to fix distorted timing
+        #ifdef __HAL_FLASH_INSTRUCTION_CACHE_DISABLE
+        __HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
+        #endif
+
+        byte((int)strip_[i].g);
+        byte((int)strip_[i].r);
+        byte((int)strip_[i].b);
+
+        #ifdef __HAL_FLASH_INSTRUCTION_CACHE_ENABLE
+        __HAL_FLASH_INSTRUCTION_CACHE_ENABLE();
+        #endif
+    }
+
+    __enable_irq();
+
+    if (flipwait) flip();
+}
+
+void NeoPixelOut::send(Pixel *colors, uint32_t count, bool flipwait)
+{
+    changeNum(count);
+    Pixel* rgb;
+    for (int i = 0; i < count; i++) {
+        rgb = colors++;
+        setPixelColor(i, rgb->hex);
+    }
+    show(flipwait);
+}
+
+uint32_t NeoPixelOut::color(uint8_t r,uint8_t g,uint8_t b){
+    return (uint32_t)b + ((uint32_t)g << 8) + ((uint32_t)r << 16);
+}
+ 
+int NeoPixelOut::numPixels(){
+    return num_pixels_;
+}
+
+void NeoPixelOut::off(bool flag){
+    for(int i = 0;i < num_pixels_;i++){
+        strip_[i].hex = 0;
+    }
+    if(flag){
+        show();
+    }
+}
+
+void NeoPixelOut::changeNum(uint32_t num){
+    if(num_pixels_ != num){
+        strip_.resize(num);
+        num_pixels_ = num;
+    }
+}
+
+void NeoPixelOut::setBrightness(float brightness){
+    global_scale = brightness;
+}
+
+void NeoPixelOut::flip(void)
+{
+    wait_us(50);
+}