STM32G4x 2 chanel Contunious Conversion Mode ADC DMA voltage read problem

Question

I am using STM32G431KB Nucleo for measure a potentiometer voltage via ADC1_IN1 and ADC1_IN2 channels with Scan Mode DMA. And my samples arrays are always zero, no change. I share my code below. What did you think the problem is?

static void MX_ADC1_Init(void) {
    // Enable the clock for ADC1
    RCC->AHB2ENR |= RCC_AHB2ENR_ADC12EN;
    RCC->AHB1ENR |= RCC_AHB1ENR_DMA1EN;
    // Configure the ADC1 clock source (assume synchronous clock mode)
    RCC->CCIPR &= ~RCC_CCIPR_ADC12SEL;
    RCC->CCIPR |= RCC_CCIPR_ADC12SEL_1;

    // Power up the ADC1
    ADC1->CR &= ~ADC_CR_DEEPPWD;
    ADC1->CR |= ADC_CR_ADVREGEN;

    // Wait for ADC voltage regulator to stabilize
    for (volatile uint32_t delay = 0; delay < 10000; delay++);

    // Disable ADC1 before calibration
    ADC1->CR &= ~ADC_CR_ADEN;

    // Calibrate the ADC1
    ADC1->CR &= ~ADC_CR_ADCALDIF;
    ADC1->CR |= ADC_CR_ADCAL;

    // Wait for calibration to complete
    while (ADC1->CR & ADC_CR_ADCAL);

    // Configure ADC common settings
    ADC12_COMMON->CCR &= ~(ADC_CCR_PRESC | ADC_CCR_CKMODE);
    ADC12_COMMON->CCR |= (ADC_CCR_CKMODE_0 | ADC_CCR_CKMODE_1);
    ADC12_COMMON->CCR |= ADC_CCR_PRESC_3;

    // Configure ADC1 resolution and continuous conversion mode
    ADC1->CFGR &= ~ADC_CFGR_RES;         // 12-bit resolution
    ADC1->CFGR |= ADC_CFGR_CONT;         // Continuous conversion mode
    ADC1->CFGR |= ADC_CFGR_DMAEN;
    ADC1->CFGR |= ADC_CFGR_DMACFG;
    // Configure ADC1 channels (sequence)
    ADC1->SQR1 &= ~ADC_SQR1_SQ1_Msk;
    ADC1->SQR1 |= (1 << ADC_SQR1_SQ1_Pos); // First conversion in regular sequence: ADC1_IN1 (PA0)
    ADC1->SQR1 &= ~ADC_SQR1_SQ2_Msk;
    ADC1->SQR1 |= (2 << ADC_SQR1_SQ2_Pos); // Second conversion in regular sequence: ADC1_IN2 (PA1)
    ADC1->SQR1 &= ~ADC_SQR1_L_Msk;
    ADC1->SQR1 |= (1 << ADC_SQR1_L_Pos);   // Sequence length: 2 conversions

    DMA1_Channel1->CPAR = (uint32_t)(&(ADC1->DR));
    DMA1_Channel1->CMAR = (uint32_t)samples;
    DMA1_Channel1->CNDTR = 2;
    DMA1_Channel1->CCR |= DMA_CCR_CIRC | DMA_CCR_MINC | DMA_CCR_PSIZE_1 | DMA_CCR_MSIZE_1 | DMA_CCR_PL_1;
    DMA1_Channel1->CCR |= DMA_CCR_EN;

    // Enable ADC1
    ADC1->CR |= ADC_CR_ADEN;

    // Wait until ADC1 is ready
    while (!(ADC1->ISR & ADC_ISR_ADRDY));

    // Start ADC1 conversion
    ADC1->CR |= ADC_CR_ADSTART;
}

I make some changes about configurations and code looks like this. Nothing solved yet. Same problem. I add ADCMUX as STM32G4 have ADCMUX block and I guess it needs a config so I make configs.

static void MX_DMA1_Init(void) {

    RCC->AHB1ENR |= RCC_AHB1ENR_DMA1EN;
    RCC->AHB1ENR |= RCC_AHB1ENR_DMAMUX1EN;
    DMAMUX1_Channel1->CCR = 0;
    DMAMUX1_Channel1->CCR |= (5 << DMAMUX_CxCR_DMAREQ_ID_Pos);
    DMA1_Channel1->CPAR = (uint32_t)(&(ADC1->DR));
    DMA1_Channel1->CMAR = (uint32_t)samples;
    DMA1_Channel1->CNDTR = 2;
    DMA1_Channel1->CCR &= ~DMA_CCR_MEM2MEM;
    DMA1_Channel1->CCR &= ~DMA_CCR_DIR;
    DMA1_Channel1->CCR |= DMA_CCR_CIRC | DMA_CCR_MINC | DMA_CCR_PSIZE_0 | DMA_CCR_MSIZE_0 | DMA_CCR_PL_1;
    DMA1_Channel1->CCR |= DMA_CCR_EN;

}

static void MX_ADC1_Init(void) {

    RCC->AHB2ENR |= RCC_AHB2ENR_ADC12EN;
    RCC->CCIPR &= ~RCC_CCIPR_ADC12SEL;
    RCC->CCIPR |= RCC_CCIPR_ADC12SEL_1;

    ADC1->CR &= ~ADC_CR_DEEPPWD;
    ADC1->CR |= ADC_CR_ADVREGEN;

    for (volatile uint32_t delay = 0; delay < 10000; delay++);

    ADC1->CR &= ~ADC_CR_ADEN;

    ADC1->CR &= ~ADC_CR_ADCALDIF;
    ADC1->CR |= ADC_CR_ADCAL;

    while (ADC1->CR & ADC_CR_ADCAL);

    ADC12_COMMON->CCR &= ~(ADC_CCR_PRESC | ADC_CCR_CKMODE);
    ADC12_COMMON->CCR |= (ADC_CCR_CKMODE_0 | ADC_CCR_CKMODE_1);
    ADC12_COMMON->CCR |= ADC_CCR_PRESC_3;


    ADC1->CFGR &= ~ADC_CFGR_RES;         // 12-bit resolution
    ADC1->CFGR |= ADC_CFGR_CONT;         // Continuous conversion mode
    ADC1->CFGR |= ADC_CFGR_DMAEN;
    ADC1->CFGR |= ADC_CFGR_DMACFG;

    ADC1->SMPR1 |= ADC_SMPR1_SMP1_2 | ADC_SMPR1_SMP2_2;
    //ADC1->CR |= ADC_CR_ADSTP;
    ADC1->SQR1 &= ~ADC_SQR1_SQ1_Msk;
    ADC1->SQR1 |= (1 << ADC_SQR1_SQ1_Pos); // First conversion in regular sequence: ADC1_IN1 (PA0)
    ADC1->SQR1 &= ~ADC_SQR1_SQ2_Msk;
    ADC1->SQR1 |= (2 << ADC_SQR1_SQ2_Pos); // Second conversion in regular sequence: ADC1_IN2 (PA1)
    ADC1->SQR1 &= ~ADC_SQR1_L_Msk;
    ADC1->SQR1 |= (1 << ADC_SQR1_L_Pos);   // Sequence length: 2 conversions


    ADC1->CR |= ADC_CR_ADEN;

    while (!(ADC1->ISR & ADC_ISR_ADRDY));

    ADC1->CR |= ADC_CR_ADSTART;

}

Other codes are RCC Config and GPIO Config I am sure they don't have an issue.

Answer 1

1. Make sure your GPIO's are configured as inputs (I believe PA1 and PA2)

2. Make sure your DMAMUX1 channel is pointed to ADC1

   DMAMUX1_Channel1->CCR = 0; DMAMUX1_Channel1->CCR |= (5 << DMAMUX_CxCR_DMAREQ_ID_Pos); // ADC1

3. Check your sampling time config:

   ADC1->SMPR1 |= ADC_SMPR1_SMP1_2 | ADC_SMPR1_SMP2_2; // Set sampling time for ADC1_IN1 and ADC1_IN2

4. Check DMA Channel configuration:

   DMA1_Channel1->CCR |= DMA_CCR_CIRC | DMA_CCR_MINC; // Circular mode, memory increment mode DMA1_Channel1->CCR |= DMA_CCR_PSIZE_0 | DMA_CCR_MSIZE_0 | DMA_CCR_PL_1; // Peripheral and memory size: 16-bit, priority level: high

But one thing you may want to do is use cubemx to set this all up and autogenerate the code and then look at that.