neopixel.cpp

00001 #include "mbed.h"
00002 #include "neopixel.h"
00003 
00004 #if defined(TARGET_NUCLEO_L432KC)
00005 
00006 #define PIXEL_WAIT_1_ (6)
00007 #define PIXEL_WAIT_2_ (2)
00008 #define PIXEL_WAIT_3_ (3)
00009 #define PIXEL_WAIT_4_ (5)
00010 
00011 #elif defined(TARGET_NUCLEO_F446RE)
00012 
00013 #define PIXEL_WAIT_1_ (9)
00014 #define PIXEL_WAIT_2_ (5)
00015 #define PIXEL_WAIT_3_ (4)
00016 #define PIXEL_WAIT_4_ (9)
00017 
00018 #else
00019 #error This board is not supported
00020 #endif
00021 
00022 NeoPixelOut::NeoPixelOut(PinName pin, int num) : DigitalOut(pin)
00023 {
00024     normalize = false;
00025     global_scale = 1.0f;
00026     num_pixels_ = num;
00027     strip_.resize(num);
00028 }
00029 
00030 // The timing should be approximately 800ns/300ns, 300ns/800ns
00031 inline void NeoPixelOut::byte(register uint32_t byte)
00032 {        
00033     for (int i = 0; i < 8; i++) {
00034         gpio_write(&gpio, 1);
00035         
00036         // duty cycle determines bit value
00037         if (byte & 0x80) {
00038             // one
00039             for(int j = 0; j < PIXEL_WAIT_1_; j++) asm("NOP");//6 9
00040             
00041             gpio_write(&gpio, 0);
00042             for(int j = 0; j < PIXEL_WAIT_2_; j++) asm("NOP");//2 5
00043         }
00044         else {
00045             // zero
00046             for(int j = 0; j < PIXEL_WAIT_3_; j++) asm("NOP");//3 4
00047             
00048             gpio_write(&gpio, 0);
00049             for(int j = 0; j < PIXEL_WAIT_4_; j++) asm("NOP");//5 9
00050         }
00051 
00052         byte = byte << 1; // shift to next bit
00053     }
00054     
00055 }
00056 
00057 void NeoPixelOut::setPixelColor(uint32_t i,uint8_t r,uint8_t g,uint8_t b){
00058     setPixelColor(i,color(r, g, b));
00059 }
00060 
00061 void NeoPixelOut::setPixelColor(uint32_t i,uint32_t color){
00062     if(i < num_pixels_){
00063         buf_.hex = color;
00064         if (normalize) {
00065             float sum = buf_.r+buf_.g+buf_.b;
00066             if(sum != 0){
00067                 float scale = 255.0f/sum;
00068                 buf_.r *= scale;
00069                 buf_.g *= scale;
00070                 buf_.b *= scale;
00071             }
00072         }
00073         buf_.r *= global_scale;
00074         buf_.g *= global_scale;
00075         buf_.b *= global_scale;
00076         
00077         strip_[i] = buf_;
00078     }
00079 }
00080 
00081 void NeoPixelOut::show(bool flipwait){
00082     // Disable interrupts in the critical section
00083     __disable_irq();
00084     
00085     for (int i = 0; i < num_pixels_; i++) {
00086         // Black magic to fix distorted timing
00087         #ifdef __HAL_FLASH_INSTRUCTION_CACHE_DISABLE
00088         __HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
00089         #endif
00090 
00091         byte((int)strip_[i].g);
00092         byte((int)strip_[i].r);
00093         byte((int)strip_[i].b);
00094 
00095         #ifdef __HAL_FLASH_INSTRUCTION_CACHE_ENABLE
00096         __HAL_FLASH_INSTRUCTION_CACHE_ENABLE();
00097         #endif
00098     }
00099 
00100     __enable_irq();
00101 
00102     if (flipwait) flip();
00103 }
00104 
00105 void NeoPixelOut::send(Pixel *colors, uint32_t count, bool flipwait)
00106 {
00107     changeNum(count);
00108     Pixel* rgb;
00109     for (int i = 0; i < count; i++) {
00110         rgb = colors++;
00111         setPixelColor(i, rgb->hex);
00112     }
00113     show(flipwait);
00114 }
00115 
00116 uint32_t NeoPixelOut::color(uint8_t r,uint8_t g,uint8_t b){
00117     return (uint32_t)b + ((uint32_t)g << 8) + ((uint32_t)r << 16);
00118 }
00119  
00120 int NeoPixelOut::numPixels(){
00121     return num_pixels_;
00122 }
00123 
00124 void NeoPixelOut::off(bool flag){
00125     for(int i = 0;i < num_pixels_;i++){
00126         strip_[i].hex = 0;
00127     }
00128     if(flag){
00129         show();
00130     }
00131 }
00132 
00133 void NeoPixelOut::changeNum(uint32_t num){
00134     if(num_pixels_ != num){
00135         strip_.resize(num);
00136         num_pixels_ = num;
00137     }
00138 }
00139 
00140 void NeoPixelOut::setBrightness(float brightness){
00141     global_scale = brightness;
00142 }
00143 
00144 void NeoPixelOut::flip(void)
00145 {
00146     wait_us(50);
00147 }