关于TIM控制DAC产生正弦波（DMA）

li547330575 · 发表于 2020-9-9 10:52:10

想实现频率可调的正弦波，就想着用TIM去控制，计时溢出就出发DMA，给DAC数据，然而始终有问题，不能采集到正弦波希望大家看看哪里错误了
程序如下：
TiM 配置：
void MX_TIM6_Init(void)
{
  TIM_MasterConfigTypeDef sMasterConfig = {0};

  htim6.Instance = TIM6;
  htim6.Init.Prescaler = 319;
  htim6.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim6.Init.Period = 9;
  htim6.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
  if (HAL_TIM_Base_Init(&htim6) != HAL_OK)
  {
Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_UPDATE;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim6, &sMasterConfig) != HAL_OK)
  {
Error_Handler();
  }

}

DAC的配置：
  sConfig.DAC_SampleAndHold = DAC_SAMPLEANDHOLD_DISABLE;
  sConfig.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
  sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
  sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_DISABLE;
  sConfig.DAC_UserTrimming = DAC_TRIMMING_FACTORY;

GPIO_InitStruct.Pin = GPIO_PIN_5;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

/* DAC1 DMA Init */
/* DAC_CH1 Init */
hdma_dac_ch1.Instance = DMA1_Channel3;
hdma_dac_ch1.Init.Request = DMA_REQUEST_6;
hdma_dac_ch1.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_dac_ch1.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_dac_ch1.Init.MemInc = DMA_MINC_ENABLE;
hdma_dac_ch1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
hdma_dac_ch1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
hdma_dac_ch1.Init.Mode = DMA_CIRCULAR;
hdma_dac_ch1.Init.Priority = DMA_PRIORITY_LOW;

主程序：
  初始化
生成正弦波数据，然后读
  void get_sineval(float Amp)          //生成正弦波函数
{
   float x;
   if(Amp>Vref/2)
{
   Amp=Vref/2;
}
for(int i=0;i<N;i++)
{
   x=(Amp*sin(2*PI*i/N));
      x=Vref/2+x;
      sine_val[i]=x*MAXDAC/Vref;
}

}
  get_sineval(1);  // 读
  HAL_TIM_Base_Start(&htim6);
  HAL_DAC_Start_DMA(&hdac1,DAC_CHANNEL_2,(uint32_t *)Sine12bit,100,DAC_ALIGN_12B_R);