Unable to read stm32f407 adc dma

[kudiarasum]

Posted on June 29, 2015 at 19:04

Hi,

I

am tyring to read 3 adc channel through DMA

using

STM32F4 discovery board ,ADC channel 10,11,12 through  PC0,PC1,PC2 . i have connected 3 volt dc to  the all three channel, but the control seems to be failed to exit from the loop while ((DMA_GetFlagStatus(DMA2_Stream4,DMA_FLAG_TCIF4)) != RESET) ; please find my piece of code below /* Define ADC init structures */ #include ''stdio.h'' #include ''stm32f4xx_adc.h'' #include ''stm32f4xx_rcc.h'' #include ''stm32f4xx_dma.h'' #include ''stm32f4xx_tim.h'' #include ''stm32f4xx_gpio.h'' #include ''misc.h'' #include ''app.h'' #define ADC_INTERNAL_REFERENCE    3300 #define ADC_12BIT_RES_COUNT 4096 #define MAX_ADC_CHANNELS    3   volatile unsigned int  ADCConvertedValues[MAX_ADC_CHANNELS];   unsigned short  ADC1_Conversion(unsigned char index) {         unsigned short ADCConvertedVoltage = 0;         unsigned short result_adc_count = 0;         while ((DMA_GetFlagStatus(DMA2_Stream4,DMA_FLAG_TCIF4)) != RESET) ;         /* Clear DMA TC flag */         DMA_ClearFlag(DMA2_Stream4,DMA_FLAG_TCIF4);         /* Compute the voltage */         result_adc_count = ADCConvertedValues[index];         printf(''result_adc_count:%d\r\n'',result_adc_count);         ADCConvertedVoltage = (result_adc_count * ADC_INTERNAL_REFERENCE) / ADC_12BIT_RES_COUNT;         return ADCConvertedVoltage; }       void adc_dma_init(void){    GPIO_InitTypeDef      GPIO_InitStructure;  ADC_InitTypeDef       ADC_InitStructure;  ADC_CommonInitTypeDef ADC_CommonInitStructure;  DMA_InitTypeDef       DMA_InitStructure;    GPIO_StructInit(&GPIO_InitStructure);  ADC_StructInit(&ADC_InitStructure);  ADC_CommonStructInit(&ADC_CommonInitStructure);  DMA_StructInit(&DMA_InitStructure);      /**    Set up the clocks are needed for the ADC  */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,ENABLE);  /**    Initialization of the GPIO Pins [OK]  */    /* Analog channel configuration : PC.01, 02*/  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_0 | 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);    /**    Config the ADC1  */  ADC_DeInit();  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; //continuous conversion  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None; // NONE !Edge!  ADC_InitStructure.ADC_NbrOfConversion = MAX_ADC_CHANNELS;  ADC_InitStructure.ADC_ScanConvMode = ENABLE; // 1=scan more that one channel in group  ADC_Init(ADC1,&ADC_InitStructure);    ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;  ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;  ADC_CommonInit(&ADC_CommonInitStructure);    ADC_RegularChannelConfig(ADC1,ADC_Channel_10,1,ADC_SampleTime_480Cycles);  ADC_RegularChannelConfig(ADC1,ADC_Channel_11,2,ADC_SampleTime_480Cycles);  ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 3, ADC_SampleTime_480Cycles);      /**    Configure the DMA  */  //==Configure DMA2 - Stream 4  DMA_DeInit(DMA2_Stream4);  //Set DMA registers to default values  DMA_InitStructure.DMA_Channel = DMA_Channel_0;  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR; //Source address  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCConvertedValues[0]; //Destination address  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;  DMA_InitStructure.DMA_BufferSize = MAX_ADC_CHANNELS; //Buffer size  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //source size - 16bit  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; // destination size = 16b  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_Stream4, &DMA_InitStructure); //Initialize the DMA  DMA_Cmd(DMA2_Stream4, ENABLE); //Enable the DMA2 - Stream 4  while(DMA_GetCmdStatus(DMA2_Stream4)==DISABLE){};    ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);  ADC_DMACmd(ADC1, ENABLE); //Enable ADC1 DMA  ADC_Cmd(ADC1, ENABLE);   // Enable ADC1  ADC_ContinuousModeCmd(ADC1,ENABLE);  ADC_SoftwareStartConv(ADC1); // Start ADC1 conversion }     int main(void) { adc_dma_init();     while(1)     {               ADC1_Conversion(0);             ADC1_Conversion(1);             ADC1_Conversion(2);           } }

A

ny one can suggest what may cause the issue for this.

regards

kudiarasu

 

[Tesla DeLorean]

Posted on June 29, 2015 at 19:14

Any one can suggest what may cause the issue for this.

The asserted state is not RESET?

[kudiarasum]

Posted on June 30, 2015 at 08:40

Thanks Clive1,

Now i have changed like below while (!DMA_GetFlagStatus(DMA2_Stream4,DMA_FLAG_TCIF4)); and control moves beyond this. But i have another issue, As mentioned in my previous post,  i have reading the ADC channels PC0, PC1 &PC2 which actually connected 2.7volts to all three pins in my stm32f407 discovery board and i am expecting 3350 as a result. But result seems to be erratic and it reads 4095,4095,0 as a results . i thing  did some mistakes in adc dma initialization . possible can you review my adc dma initialization  code ? Thanks in advance kudiarasu.

[Tesla DeLorean]

Posted on June 30, 2015 at 17:07

Skimming through it looks reasonable enough, not how I'd do it, but I've posted working examples.

PC0 has some potential issues on the STM32F4-DISCO, PC1,PC2 seem free. TC fires when all three samples are ready.