I'm trying to set up my STM32F407-Discovery board to read multiple ADC channels from ADC1 using the DMA controller. I can easily read the analog value one at a time without using DMA, but as soon as I enable DMA for the ADC, `ADC1->DR` is always 0, and `adc_vals` is filled with zeros. Furthermore, it hangs on `while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC));`.

EDIT: it would appear `DMA_GetCmdStatus` is returning DISABLED. Any ideas?

Is there a way to start the ADC or something that I'm missing?

```c
//setup adc1: in1,2,3,8,9,15
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE); //adc1 on the apb2 peripheral bus
ADC_InitTypeDef adc;
ADC_DeInit(); //set adc to default state
adc.ADC_DataAlign = ADC_DataAlign_Right;
adc.ADC_Resolution = ADC_Resolution_12b;//12 bit = 4096
adc.ADC_ContinuousConvMode = ENABLE;
adc.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
adc.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
adc.ADC_NbrOfConversion = NUM_ADC;
adc.ADC_ScanConvMode = ENABLE;
ADC_Init(ADC1,&adc);

ADC_DMACmd(ADC1, ENABLE); //enable adc for dma.  When this line is removed, I see data on ADC1->DR

ADC_Cmd(ADC1,ENABLE);

ADC_RegularChannelConfig(ADC1,ADC_Channel_1,1,ADC_SampleTime_144Cycles);//1:1710, 0
//ADC_RegularChannelConfig(ADC1,ADC_Channel_2,2,ADC_SampleTime_144Cycles);//2:1710, 0
//ADC_RegularChannelConfig(ADC1,ADC_Channel_3,3,ADC_SampleTime_144Cycles);//3:1710, 0
ADC_RegularChannelConfig(ADC1,ADC_Channel_8,4,ADC_SampleTime_144Cycles);//8:3520
ADC_RegularChannelConfig(ADC1,ADC_Channel_9,5,ADC_SampleTime_144Cycles);//9:1000
//ADC_RegularChannelConfig(ADC1,ADC_Channel_15,6,ADC_SampleTime_144Cycles);//15:3920

//DMA for multiple adc channels:
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE); //dma1 clock enable
DMA_InitTypeDef dma;

DMA_DeInit(DMA2_Stream0); //reset DMA2 stream 0 to default values
dma.DMA_Channel = DMA_Channel_0;
dma.DMA_PeripheralBaseAddr = (uint32_t)&(ADC1->DR);
dma.DMA_Memory0BaseAddr = (uint32_t)&adc_vals[0];
dma.DMA_DIR = DMA_DIR_PeripheralToMemory;
dma.DMA_BufferSize = NUM_ADC;
dma.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
dma.DMA_MemoryInc = DMA_MemoryInc_Enable;
dma.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
dma.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
dma.DMA_Mode = DMA_Mode_Circular;
dma.DMA_Priority = DMA_Priority_High;
dma.DMA_FIFOMode = DMA_FIFOMode_Disable;
dma.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
dma.DMA_MemoryBurst = DMA_MemoryBurst_Single;
dma.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream0, &dma);

DMA_ITConfig(DMA2_Stream0, DMA_IT_TC | DMA_IT_HT, ENABLE); //Enable DMA Stream Half / Transfer Complete interrupt

DMA_Cmd(DMA2_Stream0, ENABLE); //DMA2_Stream0 enable

//dma transfer complete interrupt:
NVIC_InitTypeDef nvic;
//Enable DMA1 channel IRQ Channel
nvic.NVIC_IRQChannel = DMA2_Stream0_IRQn;
nvic.NVIC_IRQChannelPreemptionPriority = 0;
nvic.NVIC_IRQChannelSubPriority = 0;
nvic.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&nvic);

ADC_SoftwareStartConv(ADC1);//Start the adc conversion

```