STM32F103C8T6驅動WS2812B源程序

ID:98798 · 發表于 2020-7-30 08:44

void Timer2_init(void)
{
      TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_OCInitTypeDef  TIM_OCInitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  DMA_InitTypeDef DMA_InitStructure;

      RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
      /* GPIOA Configuration: TIM2 Channel 1 as alternate function push-pull */
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(GPIOA, &GPIO_InitStructure);

      RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
      /* Compute the prescaler value */
      //PrescalerValue = (uint16_t) (SystemCoreClock / 24000000) - 1;
      /* Time base configuration */
      TIM_TimeBaseStructure.TIM_Period = 90-1; // 800kHz
      TIM_TimeBaseStructure.TIM_Prescaler = 0;
      TIM_TimeBaseStructure.TIM_ClockDivision = 0;
      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
      TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

      /* PWM1 Mode configuration: Channel1 */
      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_OC1Init(TIM2, &TIM_OCInitStructure);

      /* configure DMA */
      /* DMA clock enable */
      RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

      /* DMA1 Channel6 Config */
      DMA_DeInit(DMA1_Channel2);

      DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)TIM2_CCR1_Address;       // physical address of Timer 3 CCR1
      DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)LED_BYTE_Buffer;             // this is the buffer memory
      DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;                                              // data shifted from memory to peripheral
      DMA_InitStructure.DMA_BufferSize = 42;
      DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
      DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;                                     // automatically increase buffer index
      DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
      DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
      DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;                                                       // stop DMA feed after buffer size is reached
      DMA_InitStructure.DMA_Priority = DMA_Priority_High;
      DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

      DMA_Init(DMA1_Channel2, &DMA_InitStructure);

            /* TIM3 CC1 DMA Request enable */
      TIM_DMACmd(TIM2, TIM_DMA_Update, ENABLE);
}

void WS2812_send(uint8_t (*color)[3], uint16_t len)
{
      uint8_t i;
      uint16_t memaddr;
      uint16_t buffersize;
      buffersize = (len*24)+43;       // number of bytes needed is #LEDs * 24 bytes + 42 trailing bytes
      memaddr = 0;                               // reset buffer memory index

      while (len)
      {
                              for(i=0; i<8; i++) // GREEN data
                     {
                                    LED_BYTE_Buffer[memaddr] = ((color[0][1]<<i) & 0x0080) ? TIMING_ONE:TIMING_ZERO;
                                    memaddr++;
                     }
                     for(i=0; i<8; i++) // RED
                     {
                                    LED_BYTE_Buffer[memaddr] = ((color[0][0]<<i) & 0x0080) ? TIMING_ONE:TIMING_ZERO;
                                    memaddr++;
                     }
                     for(i=0; i<8; i++) // BLUE
                     {
                                    LED_BYTE_Buffer[memaddr] = ((color[0][2]<<i) & 0x0080) ? TIMING_ONE:TIMING_ZERO;
                                    memaddr++;
                     }

               len--;
      }
//===================================================================//
//bug：最后一個周期波形不知道為什么全是高電平，故增加一個波形
      LED_BYTE_Buffer[memaddr] = ((color[0][2]<<8) & 0x0080) ? TIMING_ONE:TIMING_ZERO;
//===================================================================//
      memaddr++;
            while(memaddr < buffersize)
            {
                     LED_BYTE_Buffer[memaddr] = 0;
                     memaddr++;
            }

            DMA_SetCurrDataCounter(DMA1_Channel2, buffersize);       // load number of bytes to be transferred
            DMA_Cmd(DMA1_Channel2, ENABLE);                      // enable DMA channel 6
            TIM_Cmd(TIM2, ENABLE);                                              // enable Timer 3
            while(!DMA_GetFlagStatus(DMA1_FLAG_TC2)) ;       // wait until transfer complete
            TIM_Cmd(TIM2, DISABLE);       // disable Timer 3
            DMA_Cmd(DMA1_Channel2, DISABLE);                      // disable DMA channel 6
            DMA_ClearFlag(DMA1_FLAG_TC2);                               // clear DMA1 Channel 6 transfer complete flag
}

int main(void)
{
      delay_init();          //延時函數初始化
      LED_Init();                         //初始化與LED連接的硬件接口
  Timer2_init();

      while(1)
      {
            WS2812_send(r,10);
            delay_ms(1000);
            WS2812_send(g,10);
            delay_ms(1000);
            WS2812_send(b,10);
            delay_ms(1000);
      }
}