MultiChannel(Scan) Continuous conversion mode of ADC sampling returns all 0s:

MultiChannel(Scan) Continuous conversion mode of ADC sampling returns all 0s:

Hi, I am using 6 ADC channels ADC_Channel_15,ADC_Channel_14,ADC_Channel_13,ADC_Channel_11, ADC_Channel_4,ADC_Channel_6 of STM32F107VCT6 MCU to connect to 6 devices.
I use mutichannel continuous conversion mode of ADC sampling. I enable EOC(End Of Conversion) interrupt so that i get an interrupt after a cycle of conversion is done.
I use DMA to save the converted data. When I read back the data after an interrupt is triggered, I am all getting zeros. When I instead use a polling method where I
just go and poll the channels, I could read valid data. Can any one help me with this?

/*external Variables --------------------------------------*/ uint16_t ADC_ConvertedValue[6]; b00l flag

/* Private variables ---------------------------------------------------------*/ ADC_InitTypeDef ADC_InitStructure; DMA_InitTypeDef DMA_InitStructure; GPIO_InitTypeDef GPIO_InitStructure;

/* Enable GPIO clock */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO , ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO , ENABLE);

/* PCLK2 is the APB2 clock */ /* ADCCLK = PCLK2/6 = 72/6 = 12MHz - ADCCLK should be less than 14MHz*/ RCC_ADCCLKConfig(RCC_PCLK2_Div6);

/* Enable ADC1 clock so that we can talk to it */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

/* Configure GPIO pins to have photo sensors connected to ADC channels */ GPIO_InitStructure.GPIO_Pin = R_PS_ID0_PIN | R_PS_ID1_PIN | R_PS_ID2_PIN | R_PS_ID3_PIN; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_Init(R_PS_ADC_GPIO_PORT_C, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = R_PS_ID4_PIN | R_PS_ID5_PIN; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_Init(R_PS_ADC_GPIO_PORT_A, &GPIO_InitStructure);

/* Disable the alternative GPIO pins so that ADC channel will be active */

GPIO_WriteBit(R_PS_ADC_GPIO_PORT_C, R_PS_ID0_PIN, Bit_RESET); GPIO_WriteBit(R_PS_ADC_GPIO_PORT_C, R_PS_ID1_PIN, Bit_RESET); GPIO_WriteBit(R_PS_ADC_GPIO_PORT_C, R_PS_ID2_PIN, Bit_RESET); GPIO_WriteBit(R_PS_ADC_GPIO_PORT_C, R_PS_ID3_PIN, Bit_RESET); GPIO_WriteBit(R_PS_ADC_GPIO_PORT_A, R_PS_ID4_PIN, Bit_RESET); GPIO_WriteBit(R_PS_ADC_GPIO_PORT_A, R_PS_ID5_PIN, Bit_RESET);

/* DMA Channel1 Configuration ----------------------------------------------*/ DMA_DeInit(DMA1_Channel1); DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR; DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) &ADC_ConvertedValue; DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; 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_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 DMA Channel1 */ DMA_Cmd(DMA1_Channel1, ENABLE);

/* ADCx Configuration (ADC1CLK = 12 MHz) -----------------------------------*/ ADC_InitStructure.ADC_Mode = ADC_Mode_Independent; ADC_InitStructure.ADC_ScanConvMode = ENABLE; ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None; ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right; ADC_InitStructure.ADC_NbrOfChannel = 6; ADC_Init(ADC1, &ADC_InitStructure);

/* ADCx Regular Channel Configuration */ ADC_RegularChannelConfig(ADC1, ADC_Channel_15, 1, ADC_SampleTime_1Cycles5); ADC_RegularChannelConfig(ADC1, ADC_Channel_14, 2, ADC_SampleTime_7Cycles5); ADC_RegularChannelConfig(ADC1, ADC_Channel_13, 3, ADC_SampleTime_13Cycles5); ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 4, ADC_SampleTime_28Cycles5); ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 5, ADC_SampleTime_41Cycles5); ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 6, ADC_SampleTime_55Cycles5);

/* Enable ADCx's DMA interface */ ADC_DMACmd(ADC1, ENABLE);

/* Enable ADCx */ ADC_Cmd(ADC1, ENABLE);

ADC_ITConfig(ADC1,ADC_IT_EOC,ENABLE); My_ADC_IT_Config();

/* Start ADC1 Software Conversion */ ADC_SoftwareStartConvCmd(ADC1, ENABLE);

while (1) { if(flag == TRUE) { printf("\r\n%d,%d,%d,%d,%d,%d\n",ADC_ConvertedValue[0],ADC_ConvertedValue[1],ADC_ConvertedValue[2], ADC_ConvertedValue[3],ADC_ConvertedValue[4],ADC_ConvertedValue[5]); flag = FALSE; } }

/************NVIC Configurations***************/

void R_ADC_IT_Config()
{ NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);

/* Configure and enable ADC interrupt */ NVIC_InitStructure.NVIC_IRQChannel = ADC1_2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);
}

void ADC1_2_IRQHandler(void)
{ flag = TRUE; ADC_ClearITPendingBit(ADC1, ADC_IT_EOC);
}