stm32怎么驱动ws2812，简单程序

驱动WS2812需要使用STM32的定时器和DMA模块，下面是一个简单的程序示例：

#include "stm32f10x.h"

#define LED_NUM   8
#define LED_SIZE  24
#define LED_BUFFER_SIZE  (LED_NUM * LED_SIZE)

uint8_t ledBuffer[LED_BUFFER_SIZE];

void WS2812_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  TIM_OCInitTypeDef TIM_OCInitStructure;
  DMA_InitTypeDef DMA_InitStructure;
  
  // Enable GPIO clock
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  // Configure GPIO pins for TIM3 PWM
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  
  // Enable TIM3 clock
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

  // Configure TIM3 for PWM
  TIM_TimeBaseStructure.TIM_Period = 89;
  TIM_TimeBaseStructure.TIM_Prescaler = 35;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  // Configure TIM3 PWM output for channel 3
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 0;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC3Init(TIM3, &TIM_OCInitStructure);

  // Enable TIM3 DMA request
  TIM_DMAConfig(TIM3, TIM_DMABase_CCR3, TIM_DMABurstLength_1Transfer);
  TIM_DMACmd(TIM3, TIM_DMA_CC3, ENABLE);

  // Enable DMA1 clock
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

  // Configure DMA1 Channel2 for TIM3_CH3
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(TIM3->CCR3);
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)ledBuffer;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = LED_BUFFER_SIZE;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  DMA_Init(DMA1_Channel2, &DMA_InitStructure);

  // Enable DMA1 Channel2
  DMA_Cmd(DMA1_Channel2, ENABLE);

  // Enable TIM3
  TIM_Cmd(TIM3, ENABLE);
}

void WS2812_SetColor(uint8_t ledIndex, uint8_t red, uint8_t green, uint8_t blue)
{
  uint32_t offset = ledIndex * LED_SIZE;
  uint8_t i;

  for (i = 0; i < 8; i++) {
    if (green & (1 << i)) {
      ledBuffer[offset + i] = 0xF0;
    } else {
      ledBuffer[offset + i] = 0xC0;
    }
  }

  for (i = 0; i < 8; i++) {
    if (red & (1 << i)) {
      ledBuffer[offset + i + 8] = 0xF0;
    } else {
      ledBuffer[offset + i + 8] = 0xC0;
    }
  }

  for (i = 0; i < 8; i++) {
    if (blue & (1 << i)) {
      ledBuffer[offset + i + 16] = 0xF0;
    } else {
      ledBuffer[offset + i + 16] = 0xC0;
    }
  }
}

int main(void)
{
  WS2812_Init();

  // Set LED colors
  WS2812_SetColor(0, 255, 0, 0); // Red
  WS2812_SetColor(1, 0, 255, 0); // Green
  WS2812_SetColor(2, 0, 0, 255); // Blue

  while (1) {
    // Do nothing
  }
}

在上面的代码中，WS2812_Init()函数用于初始化STM32的定时器和DMA模块，WS2812_SetColor()函数用于设置每个LED的颜色值。在主函数中，设置了前三个LED的颜色为红色、绿色和蓝色，并且进入了一个死循环。需要注意的是，WS2812的数据传输速率比较快，需要使用DMA模块来快速传输数据，否则会出现数据传输不完整或者出现花屏的问题。