Hello ,

 I have validated your code & single ADC channel is working completely fine. But when I move for Multiple ADC channel ,I'm unable to read the buffer memory. Can you please guide me through it and feel free to pin point if I'm wrong at some point.Thanks in advance.



code:

/**

 ******************************************************************************

 * @file  DMA/DMA_ADCToTIM3Transfer/main.c

 * @author MCD Application Team

 * @version V1.1.2

 * @date  14-August-2015

 * @brief  Main program body

 ******************************************************************************

 * @attention

 *

 * <h2><center>&copy; COPYRIGHT 2015 STMicroelectronics</center></h2>

 *

 * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");

 * You may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 *    http://www.st.com/software_license_agreement_liberty_v2

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.



/* Includes ------------------------------------------------------------------*/

#include "stm32f30x.h"



/** @addtogroup STM32F30x_StdPeriph_Examples

 * @{

 */



/** @addtogroup DMA_ADCToTIM3Transfer

 * @{

 */



/* Private typedef -----------------------------------------------------------*/

/* Private define ------------------------------------------------------------*/

//#define ADC1_DR_ADDRESS   0x50000040

#define TIM3_CCR3_ADDRESS  0x4000043C

/* Private macro -------------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/

__IO uint16_t calibration_value = 0;

__IO uint32_t TimingDelay = 0;

uint32_t *adc_var=0;

__IO uint32_t ADC1_DR_ADDRESS[2];

/* Private function prototypes -----------------------------------------------*/

static void ADC_Config(void);

static void DMA_Config(void);

static void TIM3_Config(void);

void Delay(__IO uint32_t nTime);

/* Private functions ---------------------------------------------------------*/



/**

 * @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

    file (startup_stm32f30x.s) before to branch to application main.

    To reconfigure the default setting of SystemInit() function, refer to

    system_stm32f30x.c file

    */

double val = 0,val1=0;



adc_var = ADC1_DR_ADDRESS;

 /* DMA1 channel1 configuration */

 DMA_Config();



 /* TIM3 channel3 configuration */

 TIM3_Config();



 /* ADC channel7 configuration */

 ADC_Config();



 while (1)

 {



/* ADC1 DMA Enable */

ADC_DMACmd(ADC1, ENABLE);

ADC_DMAConfig(ADC1, ADC_DMAMode_Circular);



/* Start ADC1 Software Conversion */

ADC_StartConversion(ADC1);

val = ADC1_DR_ADDRESS[0];

val1 = ADC1_DR_ADDRESS[1];



 }

}



/**

 * @brief Configures DMA1 channel1 to transfer data from

 *          ADC1_DR_ADDRESS to TIM3_CCR3_ADDRESS

 * @param None

 * @retval None

 */

static void DMA_Config(void)

{

 DMA_InitTypeDef DMA_InitStructure;



 /* Enable DMA1 clock */

 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);



 DMA_DeInit(DMA1_Channel1);

 DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)TIM3_CCR3_ADDRESS;

 DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADC1_DR_ADDRESS;

 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;

 DMA_InitStructure.DMA_BufferSize = 2;

 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_M2M = DMA_M2M_Disable;

 DMA_Init(DMA1_Channel1, &DMA_InitStructure);



 /* Enable DMA1 Channel1 */

 DMA_Cmd(DMA1_Channel1, ENABLE);

}



/**

 * @brief Configures the ADC1 channel7 in continuous mode.

 * @param None

 * @retval None

 */

static void ADC_Config(void)

{

 //ADC_StructInit(&GPIO_InitStructure);

 GPIO_InitTypeDef   GPIO_InitStructure;

  ADC_InitTypeDef    ADC_InitStructure;

  ADC_CommonInitTypeDef ADC_CommonInitStructure;

  uint32_t counter = 0;







  /* Enable ADC clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);

  /* Configure the ADC clock */

  RCC_ADCCLKConfig(RCC_ADC12PLLCLK_Div2);

  /* Enable GPIO clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_ADC12, ENABLE);



  /* Configure ADCx Channel 11 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(GPIOA, &GPIO_InitStructure);

  ADC_StructInit(&ADC_InitStructure);



  /* Calibration procedure */

  ADC_VoltageRegulatorCmd(ADC1, ENABLE);







 /* Calibration procedure */

 ADC_VoltageRegulatorCmd(ADC1, ENABLE);



 /* Insert delay equal to 10 µs */

 Delay(10);



 ADC_SelectCalibrationMode(ADC1, ADC_CalibrationMode_Single);

 ADC_StartCalibration(ADC1);



 while(ADC_GetCalibrationStatus(ADC1) != RESET );

 calibration_value = ADC_GetCalibrationValue(ADC1);



 /* Configure the ADC1 in continuous mode */

 ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;

 ADC_CommonInitStructure.ADC_Clock = ADC_Clock_AsynClkMode;

 ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;

 ADC_CommonInitStructure.ADC_DMAMode = ADC_DMAMode_OneShot;

 ADC_CommonInitStructure.ADC_TwoSamplingDelay = 0;



 ADC_CommonInit(ADC1, &ADC_CommonInitStructure);



 ADC_InitStructure.ADC_ContinuousConvMode = ADC_ContinuousConvMode_Enable;

 ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;

 ADC_InitStructure.ADC_ExternalTrigConvEvent = ADC_ExternalTrigConvEvent_0;

 ADC_InitStructure.ADC_ExternalTrigEventEdge = ADC_ExternalTrigEventEdge_None;

 ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;

 ADC_InitStructure.ADC_OverrunMode = ADC_OverrunMode_Disable;

 ADC_InitStructure.ADC_AutoInjMode = ADC_AutoInjec_Disable;

 ADC_InitStructure.ADC_NbrOfRegChannel = 2;

 ADC_Init(ADC1, &ADC_InitStructure);



 /* ADC1 regular channel7 configuration */

 ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_181Cycles5);

 ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_181Cycles5);



 /* Enable ADC1 */

 ADC_Cmd(ADC1, ENABLE);



 /* wait for ADRDY */

 while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_RDY));



 /* ADC1 DMA Enable */

 ADC_DMACmd(ADC1, ENABLE);

 ADC_DMAConfig(ADC1, ADC_DMAMode_Circular);



 /* Start ADC1 Software Conversion */

 ADC_StartConversion(ADC1);

}



/**

 * @brief Configures the TIM3 channel3 in PWM mode

 * @param None

 * @retval None

 */

static void TIM3_Config(void)

{

 TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

 TIM_OCInitTypeDef     TIM_OCInitStructure;

 GPIO_InitTypeDef     GPIO_InitStructure;



 /* Enable GPIOB clock */

 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);



 /* GPIOB Configuration: PB0(TIM3 CH3) as alternate function push-pull */

 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

 GPIO_Init(GPIOB, &GPIO_InitStructure);

 GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_2);



 /* Enable TIM3 clock */

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);



 /* Time Base configuration */

 TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);

 TIM_TimeBaseStructure.TIM_Period = 0xFF0;

 TIM_TimeBaseStructure.TIM_Prescaler = 0x0;

 TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;

 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);



 /* Channel3 Configuration in PWM mode */

 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

 TIM_OCInitStructure.TIM_Pulse = 0xF0;

 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

 TIM_OC3Init(TIM3, &TIM_OCInitStructure);



 /* Enable TIM3 */

 TIM_Cmd(TIM3, ENABLE);

}



/**

 * @brief Inserts a delay time.

 * @param nTime: specifies the delay time length, in milliseconds.

 * @retval None

 */

void Delay(__IO uint32_t nTime)

{

TimingDelay = nTime;



 while(TimingDelay--!= 0);

}