我有一个带有stm32f407vg uC的stm32f4-discovery，我正在尝试对ADC1进行编程，并使用它来测量PC5端口上的一些信号。根据文档PC5挂在ADC12_IN15上，我将其解释为ADC1和ADC2通道15。我想使用STD库STM32F4xx_DSP_StdPeriph_Lib_V1.6.1中的ADC_DMA示例项目。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，偏移为2V。然后，我运行以下代码，该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);
}
当我在行上设置断点时
uwADCxConvertedVoltage = uhADCxConvertedValue *3300/0xFFF;
该变量始终为零。此外，我发现在操作期间ADC1寄存器或DMA2寄存器中没有任何变化，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。好像功能
ADC_SoftwareStartConv(ADCx);
无法设置SWSTART标志，并且永远不会执行转换。
有什么事吗
最佳答案
您似乎配置了错误的DMA流/通道。您选择ADC1，但配置DMA_Channel_1。您需要使用DMA_Channel_0配置DMA_Stream_0。下表显示了DMA流/通道配置。