Stm32F4 DMA+ADC cannot work

stm32f4 · ‎2014-05-09

Posted on May 09, 2014 at 12:25

Hi all.

I'm trying to work with ADC and DMA. The adc works, i'm able to read directly value form pin PC1.

When i try to read it using DMA a get alway zero value.

I'm try to get work example from stm32f4_dsp_stdperiph_lib but nothing. I'm newbe.

Someone could give me an hint.

The source i use is this:

tatic 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(RCC_AHB1Periph_GPIOC, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

/* DMA2 Stream0 channel2 configuration **************************************/

DMA_InitStructure.DMA_Channel = DMA_Channel_2;

DMA_InitStructure.DMA_PeripheralBaseAddr = ((uint32_t)0x4001204C);

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(DMA2_Stream0, &DMA_InitStructure);

DMA_Cmd(DMA2_Stream0, ENABLE);

/* Configure ADC3 Channel7 pin as analog input ******************************/

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;

GPIO_Init(GPIOC, &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);

/* 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_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;

ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;

ADC_InitStructure.ADC_NbrOfConversion = 1;

ADC_Init(ADC1, &ADC_InitStructure);

/* ADC3 regular channel7 configuration **************************************/

ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 1, ADC_SampleTime_3Cycles);

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

ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);

/* Enable ADC3 DMA */

ADC_DMACmd(ADC1, ENABLE);

/* Enable ADC3 */

ADC_Cmd(ADC1, ENABLE);

}

int

main(void)

{

#if defined(DEBUG)

/*

* Send a greeting to the standard output (the semihosting debug channel

* on Debug, ignored on Release).

*/

printf(''Hello ARM World!\n'');

#endif

/* ADC configuration */

ADC_Config();

/* Start ADC Software Conversion */

ADC_SoftwareStartConv(ADC1);

/*

* At this stage the microcontroller clock setting is already configured,

* this is done through SystemInit() function which is called from startup

* files (startup_cm.c) before to branch to the

* application main. To reconfigure the default setting of SystemInit()

* function, refer to system_stm32f4xx.c file.

*/

RCC_ClocksTypeDef RCC_Clocks;

/* Use SysTick as reference for the timer */

RCC_GetClocksFreq(&RCC_Clocks);

SysTick_Config(RCC_Clocks.HCLK_Frequency / SYSTICK_FREQUENCY_HZ);

/* GPIO Periph clock enable */

RCC_AHB1PeriphClockCmd(BLINK_RCC_BIT, ENABLE);

GPIO_InitTypeDef GPIO_InitStructure;

/* Configure pin in output push/pull mode */

GPIO_InitStructure.GPIO_Pin = (1 << BLINK_PIN);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(BLINK_PORT, &GPIO_InitStructure);

int seconds = 0;

/* Infinite loop */

while (1)

{

uwADCxConvertedVoltage = uhADCxConvertedValue *3300/0xFFF;

#if defined(DEBUG)

/*

* Count seconds on the debug channel.

*/

printf(''ADC value = %d\n'', uwADCxConvertedVoltage);

#endif

if (uwADCxConvertedVoltage >0)

{

/* Turn on led by setting the pin low */

GPIO_ResetBits(BLINK_PORT, (1 << BLINK_PIN));

Delay(BLINK_TICKS);

/* Turn off led by setting the pin high */

GPIO_SetBits(BLINK_PORT, (1 << BLINK_PIN));

Delay(BLINK_TICKS);

}

++seconds;

#if defined(DEBUG)

/*

* Count seconds on the debug channel.

*/

printf(''Second %d\n'', seconds);

#endif

}

Thanks in advance.

Carmelo.

stm32f4 · ‎2014-05-09

Posted on May 09, 2014 at 13:21

Hi all.

I think i foud my error:

Wrong DMA channel:

DMA_InitStructure.DMA_Channel = DMA_Channel_0;

Thanks

Carmelo