无法使stm32f4-discovery的ADC工作

Question

我有一个带有 stm32f407vg uC 的 stm32f4-discovery，我正在尝试对 ADC1 进行编程并用它测量端口 PC5 上的一些信号。根据文档，PC5 卡在 ADC12_IN15 上，我将其解释为 ADC1 和 ADC2 channel 15。我想使用 STD 库 STM32F4xx_DSP_StdPeriph_Lib_V1.6.1 中的 ADC_DMA 示例项目。发送到 PC5 的信号由信号发生器提供，它是一个方波信号，频率为 10 Hz，Vpp 为 900 mV，偏移量为 2 V。然后我运行以下代码，已成功编译并上传:

#define ADCx                     ADC1
#define ADC_CHANNEL              ADC_Channel_15
#define ADCx_CLK                 RCC_APB2Periph_ADC1
#define ADCx_CHANNEL_GPIO_CLK    RCC_AHB1Periph_GPIOC
#define GPIO_PIN                 GPIO_Pin_5
#define GPIO_PORT                GPIOC
#define DMA_CHANNELx             DMA_Channel_0
#define DMA_STREAMx              DMA2_Stream0
#define ADCx_DR_ADDRESS          ((uint32_t)0x4001224C)
static void ADC_Config(void);
/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /*!< At this stage the microcontroller clock setting is already configured, 
       this is done through SystemInit() function which is called from startup
       files (startup_stm32f40_41xxx.s/startup_stm32f427_437xx.s/startup_stm32f429_439xx.s)
       before to branch to application main. 
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f4xx.c file
     */






  /* ADC configuration */
  ADC_Config();


  /* Start ADC Software Conversion */ 
  ADC_SoftwareStartConv(ADCx);


  while (1)
  {
    uwADCxConvertedVoltage = uhADCxConvertedValue *3300/0xFFF;
  }
}


/**
  * @brief  ADC3 channel07 with DMA configuration
  * @note   This function Configure the ADC peripheral  
            1) Enable peripheral clocks
            2) DMA2_Stream0 channel2 configuration
            3) Configure ADC Channel7 pin as analog input
            4) Configure ADC3 Channel7 
  * @param  None
  * @retval None
  */
static void ADC_Config(void)
{
  ADC_InitTypeDef       ADC_InitStructure;
  ADC_CommonInitTypeDef ADC_CommonInitStructure;
  DMA_InitTypeDef       DMA_InitStructure;
  GPIO_InitTypeDef      GPIO_InitStructure;


  /* Enable ADCx, DMA and GPIO clocks ****************************************/ 
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
  RCC_AHB1PeriphClockCmd(ADCx_CHANNEL_GPIO_CLK, ENABLE);  
  RCC_APB2PeriphClockCmd(ADCx_CLK, ENABLE);



  /* DMA2 Stream0 channel15 configuration **************************************/
  DMA_InitStructure.DMA_Channel = DMA_CHANNELx;  
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADCx_DR_ADDRESS;
  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&uhADCxConvertedValue;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
  DMA_InitStructure.DMA_BufferSize = 1;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;
  DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
  DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
  DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
  DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
  DMA_Init(DMA_STREAMx, &DMA_InitStructure);
  DMA_Cmd(DMA_STREAMx, ENABLE);


  /* Configure ADC1 Channel15 pin as analog input ******************************/
  GPIO_InitStructure.GPIO_Pin = GPIO_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
  GPIO_Init(GPIO_PORT, &GPIO_InitStructure);


  /* ADC Common Init **********************************************************/
  ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
  ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
  ADC_CommonInit(&ADC_CommonInitStructure);


  /* ADC1 Init ****************************************************************/
  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
  ADC_InitStructure.ADC_ScanConvMode = DISABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 1;
  ADC_Init(ADCx, &ADC_InitStructure);


  /* ADC1 regular channel15 configuration **************************************/
  ADC_RegularChannelConfig(ADCx, ADC_CHANNEL, 1, ADC_SampleTime_3Cycles);


 /* Enable DMA request after last transfer (Single-ADC mode) */
  ADC_DMARequestAfterLastTransferCmd(ADCx, ENABLE);


  /* Enable ADC1 DMA */
  ADC_DMACmd(ADCx, ENABLE);


  /* Enable ADC1 */
  ADC_Cmd(ADCx, ENABLE);
}

当我在该行设置断点时

uwADCxConvertedVoltage = uhADCxConvertedValue *3300/0xFFF;

变量始终为零。此外，我发现在操作期间 ADC1 寄存器或 DMA2 寄存器没有变化，并且 ADC_CR2 寄存器的 SWSTART 标志从未设置。 ADC_DR 寄存器也始终为 0。好像是这个函数

ADC_SoftwareStartConv(ADCx);

无法设置 SWSTART 标志并且永远不会执行转换。

可能出了什么问题？

Answer 1

您似乎配置了错误的 DMA 流/ channel 。您选择 ADC1 但配置 DMA_Channel_1。您需要使用 DMA_Stream_0 配置 DMA_Channel_0。下表显示了 DMA 流/ channel 配置。