FAQs
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 

What am I missing? ADC again...

jamsoft
Associate II

‎2013-04-27 04:07 AM

Posted on April 27, 2013 at 13:07

Hi all,

I've the following problem. I need to measure signal on the PC.00 pin and with the code bellow it doesn't work. :( However, if I change the pin to PC.02 and Channel 12 , everything works fine and I get the proper value for voltage on the PC.02 pin. What am I missing that on PC.00 it doesn't work and od the PC.02 is everything OK? Note, I've created a new project for test and nothing else is using the PC.00 pin. The board in question is STM32F4 Discovery.

Code:

#include ''stm32f4xx.h''

#include ''stm32f4_discovery.h''

#define ADC_CDR_ADDRESS    ((uint32_t)0x40012308)

__IO uint16_t ADCTripleConvertedValueUS0[3];

uint16_t ADC_Val; //Stores the calculated ADC value

double voltage1; //Used to store the actual voltage calculated by ADC for the 1st channel

double voltage2; //Used to store the actual voltage calculated by ADC for the 2nd channel

double voltage3; //Used to store the actual voltage calculated by ADC for the 3rd channel

ADC_InitTypeDef       ADC_InitStructure;

ADC_CommonInitTypeDef ADC_CommonInitStructure;

DMA_InitTypeDef       DMA_InitStructure;

GPIO_InitTypeDef      GPIO_InitStructure;

int main(void)

{

  /* Enable peripheral clocks */

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 |

                         RCC_APB2Periph_ADC3, ENABLE);

  /* Configure ADC Channel 10 pin as analog input */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //GPIO C.00

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;

  GPIO_Init(GPIOC, &GPIO_InitStructure);

    

  /* DMA2 Stream0 channel0 configuration */

  DMA_InitStructure.DMA_Channel = DMA_Channel_0;  

  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC_CDR_ADDRESS;

  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCTripleConvertedValueUS0;

  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;

  DMA_InitStructure.DMA_BufferSize = 3;

  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;

  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;

  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);

  /* DMA2_Stream0 enable */

  DMA_Cmd(DMA2_Stream0, ENABLE);

    

/******************************************************************************/

/*  ADCs configuration: triple interleaved with 5cycles delay to reach 6Msps  */

/******************************************************************************/

  /* ADC Common configuration *************************************************/

  ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_Interl;

  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;

  ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_2;  

  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;

  ADC_CommonInit(&ADC_CommonInitStructure);

  /* ADC1 regular channel 10 configuration ************************************/

  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(ADC1, &ADC_InitStructure);

  ADC_RegularChannelConfig(ADC1, ADC_Channel_10, 1, ADC_SampleTime_3Cycles); 

 

  /* Enable ADC1 DMA */

  ADC_DMACmd(ADC1, ENABLE);

  /* ADC2 regular channel 10 configuration ************************************/

  ADC_Init(ADC2, &ADC_InitStructure);

 

    /* ADC2 regular channel 10 configuration */

    ADC_RegularChannelConfig(ADC2, ADC_Channel_10, 1, ADC_SampleTime_3Cycles); 

  /* ADC3 regular channel 10 configuration ************************************/

  ADC_Init(ADC3, &ADC_InitStructure);

 

  /* ADC3 regular channel 10 configuration *************************************/

  ADC_RegularChannelConfig(ADC3, ADC_Channel_10, 1, ADC_SampleTime_3Cycles);   

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

  ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE);

  /* Enable ADC1 **************************************************************/

  ADC_Cmd(ADC1, ENABLE);

  /* Enable ADC2 **************************************************************/

  ADC_Cmd(ADC2, ENABLE);

  /* Enable ADC3 **************************************************************/

  ADC_Cmd(ADC3, ENABLE);

    

  /* Start ADC1 Software Conversion */

  ADC_SoftwareStartConv(ADC1);

    

    

    //Led Init

    STM_EVAL_LEDInit(LED3);

    STM_EVAL_LEDInit(LED4);

    STM_EVAL_LEDInit(LED5);

    STM_EVAL_LEDInit(LED6);

    

  while (1)

  {

     STM_EVAL_LEDOff(LED3);

     STM_EVAL_LEDOff(LED4);

     STM_EVAL_LEDOff(LED5);

     STM_EVAL_LEDOff(LED6);

     ADC_Val = ADCTripleConvertedValueUS0[0];

     voltage1 = (3.3 * ADC_Val) / 4096;

     ADC_Val = ADCTripleConvertedValueUS0[1];

     voltage2 = (3.3 * ADC_Val) / 4096;

        

     ADC_Val = ADCTripleConvertedValueUS0[1];

     voltage3 = (3.3 * ADC_Val) / 4096;    

        

     voltage1 = (voltage1 + voltage2 + voltage3)/3;    

     if ((voltage1 >= 0) && (voltage1 < 0.2)) {

         STM_EVAL_LEDOn(LED3);

     } else if ((voltage1 >= 0.2) && (voltage1 < 0.4)) {

         STM_EVAL_LEDOn(LED4);

     } else if ((voltage1 >= 0.4) && (voltage1 < 0.5)) {

         STM_EVAL_LEDOn(LED5);

     } else {//voltage1 >= 0.5

         STM_EVAL_LEDOn(LED6);

     }    

         

  }

}

Thank you for your answers.
0 Kudos
10 REPLIES 10
Tesla DeLorean
Guru

‎2013-04-29 08:00 AM

Posted on April 29, 2013 at 17:00

Any idea? 

__IO uint32_t ADCConvertedValues[6];
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
/* Configure ADC pins as analog input */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3; //GPIO A, channels 0, 1, 2, 3
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2; //GPIO C, channels 11, 12
GPIO_Init(GPIOC, &GPIO_InitStructure);
// DMA:
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t) &ADCConvertedValues[0];
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 6;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
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:
ADC_DeInit();
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);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
 ADC_InitStructure.ADC_ExternalTrigConv = 0;

ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 6;
ADC_Init(ADC1,&ADC_InitStructure);
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 5, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 6, ADC_SampleTime_3Cycles);
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* Enable ADC1 **************************************************************/
ADC_Cmd(ADC1, ENABLE);
/* Start ADC1 Software Conversion */
ADC_SoftwareStartConv(ADC1);
while(1); // Don't want to exit
}

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..
0 Kudos
Top