Simple neopixel (WS2812) library, tuned for stm32 (L432) at 80 MHz Should be compatible with any stm32, different clock speed may require timing adjustments in neopixel.c
Dependents: F746_projet_led_version_final
neopixel.cpp
- Committer:
- marcolasek
- Date:
- 2019-06-04
- Revision:
- 1:911fe4d70205
- Parent:
- 0:a81364d9a67b
File content as of revision 1:911fe4d70205:
#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++) { //8 gpio_write(&gpio, 1); // duty cycle determines bit value if (byte & 0x80) { // one for(int j = 0; j < 72; j++) __nop();//6 gpio_write(&gpio, 0); for(int j = 0; j < 24; j++) __nop();//2 } else { // zero for(int j = 0; j < 24; j++) __nop();//2 gpio_write(&gpio, 0); for(int j = 0; j < 60; j++) __nop();//5 } 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); }