STM32F4 ADC DMA config not working - c

Question

I'm trying to get ADC with DMA working on my STM32F411RE nucleo board.
the signal is connected to the PC0 pin (ADC channel 10, DMA2), but whenever I check, the uhADC1ConvertedValue is 0. Am I missing something? Is my config wrong?
__IO uint32_t uhADC1ConvertedValue;
unsigned int getADCVal(){
return uhADC1ConvertedValue;
}
void ADC2_Init(){
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
uhADC1ConvertedValue = 1;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&uhADC1ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 1;
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_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);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
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 = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
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);
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
ADC_DMACmd(ADC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
ADC_EOCOnEachRegularChannelCmd(ADC1, ENABLE);
}
int main(void)
{
int rev = 0;
uC_Init();
rev = getADCVal(); //enc28j60getrev();
simple_server();
return rev;
}

Answer 1

I can't really tell what was wrong with my previous code (probably the part where i didn't start the timer that would start the ADC), but here is a working one (this code keeps ADC doing conversions continously (well, started by a timer) and loads the measured value into a variable):
volatile uint32_t uhADC1ConvertedValue;
uint32_t getADCVal(){
return uhADC1ConvertedValue;
}
void adc_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
RCC->AHB1ENR |= RCC_AHB1ENR_DMA2EN;
//konfiguracja ADC
ADC1->CR2 = ADC_CR2_ADON | //włącz ADC
ADC_CR2_EXTEN_0 | //wyzwalanie przetwornika zboczem opadającym i narastającym
ADC_CR2_EXTSEL_3 | ADC_CR2_EXTSEL_0 | //wyzwalanie przetwornika kanałem 4 timera 4
ADC_CR2_DDS | //kontynuuj przesył DMA po ostatnim przesyle (konieczne dla circular mode)
ADC_CR2_DMA; //włącz DMA dla ADC
//włączenie skanowania i przerwania dla zakonczonej konwersji
ADC1->CR1 = ADC_CR1_SCAN; //| ADC_CR1_EOCIE;
//Ustawienie czasu konwersji na 3 + 12 cykli zegara ADC, zegar ADC == 42MHz częstotliwosć próbkowania ~1Ms
ADC1->SMPR1 = 0;//ADC_SMPR1_SMP11_1 | ADC_SMPR1_SMP12_1;
//Ustawienie ilosci kanałów do skanowania
ADC1->SQR1 = (1)<<20;
//Ustawienie kanałów 11 i 12 do skanowania
ADC1->SQR3 = 10<<5;
//Konfiguracja DMA dla przetwornika ADC1
DMA2_Stream0->NDTR = 1; //ilosc bajtów do przesłania
DMA2_Stream0->PAR = (uint32_t)&ADC1->DR;
DMA2_Stream0->M0AR = (uint32_t)&uhADC1ConvertedValue;
DMA2_Stream0->CR = DMA_SxCR_PL_1 | //priority high
DMA_SxCR_MSIZE_0 | //memory size 16bit
DMA_SxCR_PSIZE_0 | //pheriperial size 16bit
DMA_SxCR_MINC | //inkrementuj wskaźnik po stronie pamięci
DMA_SxCR_CIRC | //zapętlenie bufora pamięci
DMA_SxCR_EN; //włączenie kontrolera DMA
//konfiguracja timera dla przetwornika
RCC->APB1ENR |= RCC_APB1ENR_TIM4EN;
TIM4->CR1 = 0; //resetowanie rejestru konfiguracji
TIM4->PSC = 0; //prescaller na 0
TIM4->ARR = 167; //reload register na 83
TIM4->CCR4 = 167; //rejesrt compare dla wyzwalania przetwornika
TIM4->CCMR2 |= TIM_CCMR2_OC4M_0 | TIM_CCMR2_OC4M_1; //przełączanie wyjcia przy compare
TIM4->CCER |= TIM_CCER_CC4E; //włączenie wyjcia 4
//konfiguracja NVIC
NVIC_EnableIRQ(ADC_IRQn); //przerwanie od zakonczenia konwersji ADC
//uruchom przetwornik
ADC1->CR2 |= ADC_CR2_ADON;
//uruchom timer
TIM4->CR1 = TIM_CR1_CEN;
}
int main(void)
{
uint32_t rev;
int bb= 0;
uC_Init();
//ADC2_Init();
adc_init();
rev = uhADC1ConvertedValue;
rev = uhADC1ConvertedValue;
rev = uhADC1ConvertedValue;
for (bb=0; bb< 100000; bb++) // tu dociera i sie wywala
{;;}
rev = uhADC1ConvertedValue;
rev = uhADC1ConvertedValue;
rev = uhADC1ConvertedValue;
rev = uhADC1ConvertedValue;
// rev = 20;
/**/
simple_server(); //petla nieskonczona
return rev;
}