Diff: neopixel.cpp

Revision:

0:a81364d9a67b

Child:

1:415459e3f93b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/neopixel.cpp	Tue Mar 21 21:17:08 2017 +0000
@@ -0,0 +1,91 @@
+#include "mbed.h"
+#include "neopixel.h"
+
+NeoPixelOut::NeoPixelOut(PinName pin) : DigitalOut(pin)
+{
+     normalize = false;
+     global_scale = 1.0f;
+}
+
+// The timing should be approximately 800ns/300ns, 300ns/800ns
+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 < 6; j++) __nop();
+            
+            gpio_write(&gpio, 0);
+            for(int j = 0; j < 2; j++) __nop();
+        }
+        else {
+            // zero
+            for(int j = 0; j < 2; j++) __nop();
+            
+            gpio_write(&gpio, 0);
+            for(int j = 0; j < 5; j++) __nop();
+        }
+
+        byte = byte << 1; // shift to next bit
+    }
+    
+}
+
+void NeoPixelOut::send(Pixel *colors, uint32_t count, bool flipwait)
+{
+    // Disable interrupts in the critical section
+    __disable_irq();
+
+    Pixel* rgb;
+    float fr,fg,fb;
+    for (int i = 0; i < count; i++) {
+        rgb = colors++;
+        fr = (int)rgb->r;
+        fg = (int)rgb->g;
+        fb = (int)rgb->b;
+        
+        if (normalize) {
+            float scale = 255.0f/(fr+fg+fb);           
+            fr *= scale;
+            fg *= scale;
+            fb *= scale;            
+        }
+        
+        fr *= global_scale;
+        fg *= global_scale;
+        fb *= global_scale;
+        
+        if (fr > 255) fr = 255; 
+        if (fg > 255) fg = 255;
+        if (fb > 255) fb = 255;
+        if (fr < 0) fr = 0; 
+        if (fg < 0) fg = 0;
+        if (fb < 0) fb = 0;
+        
+        // Black magic to fix distorted timing
+        #ifdef __HAL_FLASH_INSTRUCTION_CACHE_DISABLE
+        __HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
+        #endif
+        
+        byte((int)fg);
+        byte((int)fr);
+        byte((int)fb);
+        
+        #ifdef __HAL_FLASH_INSTRUCTION_CACHE_ENABLE
+        __HAL_FLASH_INSTRUCTION_CACHE_ENABLE();
+        #endif
+    }
+
+    __enable_irq();
+
+    if (flipwait) flip();   
+}
+
+
+void NeoPixelOut::flip(void)
+{
+    wait_us(50);    
+}