STM32F407ADC采样实验

/*定义ADC3的数据寄存器地址，DMA功能要用到外设的数据地址

 *ADC3的数据地址为外设基地址+偏移地址，基地址在RM0090 Reference

 *manual（参考手册）的地址映射表里，为0x40012200，ADC_DR

 *偏移地址为0x4C，故实际地址为0x40012200+0x4C = 0x4001224C */

#define ADC3_DR_Address   ((uint32_t)0x4001224C)



代码详见:



void Adc3_Init(void)



        {



                        /* Enable peripheral clocks ------------------------------------------------*/



                /* Enable DMA1 clock */ 



                RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC, ENABLE);



               RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);



                GPIO_Configuration();



                DMA_Configuration();





        }



void DMA_Configuration(void)



{



        ADC_InitTypeDef ADC_InitStructure;



  DMA_InitTypeDef DMA_InitStructure;



        ADC_CommonInitTypeDef ADC_CommonInitStructure;



  /* DMA2 Stream0 channel0 configuration **************************************/



  DMA_InitStructure.DMA_Channel = DMA_Channel_2;  



  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_Address;



  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCConvertedValue;



  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(DMA2_Stream0, &DMA_InitStructure);



  DMA_Cmd(DMA2_Stream0, ENABLE);



  /* 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);



  /* ADC3 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_DataAlign = ADC_DataAlign_Right;



  ADC_InitStructure.ADC_NbrOfConversion = 1;



  ADC_Init(ADC3, &ADC_InitStructure);



  /* ADC3 regular channel12 configuration *************************************/



  ADC_RegularChannelConfig(ADC3, ADC_Channel_12, 1, ADC_SampleTime_3Cycles);



 /* Enable DMA request after last transfer (Single-ADC mode) */



  ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);



  /* Enable ADC3 DMA */



  ADC_DMACmd(ADC3, ENABLE);



  /* Enable ADC3 */



  ADC_Cmd(ADC3, ENABLE);



        /* Start ADC3 Software Conversion */ 



  ADC_SoftwareStartConv(ADC3);   //如果不是外部触发则必须软件开始转换



}









/**



  * [url=home.php?mod=space&uid=247401]@brief[/url]  Configures the different GPIO ports.



  * @param  None



  * @retval None



  */



void GPIO_Configuration(void)



{



  GPIO_InitTypeDef GPIO_InitStructure;



  /* Configure PC.2 (ADC Channel2) PC.1 (ADC Channel1) as analog input -------------------------*/



  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1|GPIO_Pin_2;



  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;



  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;



  GPIO_Init(GPIOC, &GPIO_InitStructure);



}