Problem reading data from multiple ADC channels with stm32f4-discovery board using DMA - dma

Question

I am trying to read data from channel 0,1,2 and 3 of ADC1. The issue is that when I read from channel 1 and channel 2 and run the code in debug mode it shows the correct valueenter image description heres but when I modified it for doing the same for channel 3 and 4 also,it does not show any value.Following is the code and the screen shot of memory map:
#include "stm32f4xx.h"
#include "stm32f4_discovery.h"
uint16_t ADC1ConvertedValue[4] = {0,0,0,0};//Stores converted vals [2] = {0,0}
void DMA_config()
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 ,ENABLE);
DMA_InitTypeDef DMA_InitStruct;
DMA_InitStruct.DMA_Channel = DMA_Channel_0;
DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t) 0x4001204C;//ADC1's data register
DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t)&ADC1ConvertedValue;
DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStruct.DMA_BufferSize = 4;//2
DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//Reads 16 bit values _HalfWord
DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//Stores 16 bit values _Halfword
DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;
DMA_InitStruct.DMA_Priority = DMA_Priority_High;
DMA_InitStruct.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStruct.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;//_HalfFull
DMA_InitStruct.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStruct.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream0, &DMA_InitStruct);
DMA_Cmd(DMA2_Stream0, ENABLE);
}
void ADC_config()
{
/* Configure GPIO pins ******************************************************/
ADC_InitTypeDef ADC_InitStruct;
ADC_CommonInitTypeDef ADC_CommonInitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
RCC_AHB1PeriphClockCmd( RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);//ADC1 is connected to the APB2 peripheral bus
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;// PA0,PA1,PA3,PA3
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AN;//The pins are configured in analog mode
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL ;//We don't need any pull up or pull down
GPIO_Init(GPIOA, &GPIO_InitStruct);//Initialize GPIOA pins with the configuration
/* ADC Common Init **********************************************************/
ADC_CommonInitStruct.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStruct.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStruct.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStruct.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStruct);
/* ADC1 Init ****************************************************************/
ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;//Input voltage is converted into a 12bit int (max 4095)
ADC_InitStruct.ADC_ScanConvMode = ENABLE;//The scan is configured in multiple channels
ADC_InitStruct.ADC_ContinuousConvMode = ENABLE;//Continuous conversion: input signal is sampled more than once
ADC_InitStruct.ADC_ExternalTrigConv = DISABLE;
ADC_InitStruct.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;//Data converted will be shifted to right
ADC_InitStruct.ADC_NbrOfConversion = 4;
ADC_Init(ADC1, &ADC_InitStruct);//Initialize ADC with the configuration
/* Select the channels to be read from **************************************/
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_144Cycles);//PA0
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_144Cycles);//PA1
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_144Cycles);//PA2
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_144Cycles);//PA3
/* Enable DMA request after last transfer (Single-ADC mode) */
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
}
int main(void)
{
DMA_config();
ADC_config();
while(1)
{
ADC_SoftwareStartConv(ADC1);
//value=ADC_Read();
}
return 0;
}

Answer 1

You shouldn't start the ADC conversion multiple times (in your while(1) loop).
Since you've configured the ADC with .ADC_ContinuousConvMode = ENABLE it should be enough to start it before the loop and do nothing within it.