STM32G431KB DAC DMA not working

[PBieg.1]

Trying to get a basic sample DAC1 with DMA, triggered by TIM2 working.

This should be trivial, works fine on SMT32F3. I'm using a Nucleo-32 SMT32G431.

Using Cube IDE. The only non IDE-generated code in main is:

 /* USER CODE BEGIN 2 */
 
 static uint16_t x[4];
 x[0]= 100;
 x[1]= 1000;
 x[2]= 2000;
 x[3]= 3000;
 
 HAL_TIM_Base_Start_IT(&htim2);
 HAL_DAC_Start_DMA(&hdac1, DAC_CHANNEL_1, (uint32_t*)x, 4, DAC_ALIGN_12B_R);
 
 /* USER CODE END 2 */

IOC configuration:

• DAC with output buffer (verified, works fine in non-DMA mode)
• circular DMA buffer, 1/2 word
• trigger: TIM2 update
• TIM2: set to count up to 500, internal clock (works, verified by reading the clock)

Compared to some DAC/DMA examples - everything seems fine (and works on a Nucleo-32 SMT32F3. Please help - this is extremely frustrating and has held up a a project for 3 days.

test1.ioc and main.c files attached.

Thank you!

Paul

[waclawek.jan]

I'm not going to investigate this, but IIRC DMAMUX in Cube (some other STM32 family's which has DMAMUX I looked at some time ago) is set automagically inside some of the usual DMA setup functions, so CubeMX does not need to be aware of it. I may be mistaken, I obviously don't Cube.

JW

[SSorr.1]

Great thread! I am facing the same issue on a STM32G431 processor, I copied the code posted above with the proposed changes​, but the DAC out is not updating, despite a running timer.

​

I​ suspect that I missed something in the DMAMUX, is there anyone so kind to explain whether more DMAMUX registers need to be updated? Thanks!

[rclar.6]

Me too. Only strangely the version I made for the nucleo board works on the 100 pin chip used for the PCBs made. I solved the ADC by using a HAL_DMA_init() call that I never had to use before (perhaps later versions of the CubeMX used to put this call in and now don't?). However the DAC output which used to work fine on a neucleo board simply does not start. The

 

    if (HAL_DAC_Start_DMA(&hdac3, DAC_CHANNEL_2, (uint32_t*) &dac_data_out[0], size,
      DAC_ALIGN_12B_R) != HAL_OK) {
      Error_Handler();
    }

Returns HAL_OK. The DMA simply just does not start.

[rclar.6]

FOR the STM32G series: I found out what this was. In the GUI you have to make the word size WORD even though its a 12 bit DAC. Strangely there is no error message if you try to use half word AND when you run the code it simply does not start. Subtle one.

[Paul3]

That worked for me i.e. changing Half Word to Word. Thanks!

[Sanjeok]

I tried with STM32G431CBT6 but failed by Arduino IDE.

bool initDMA( uint8_t pin, uint8_t *wave, uint32_t freq, uint32_t len ) {
// https://vivonomicon.com/2019/07/05/bare-metal-stm32-programming-part-9-dma-megamix/ -- DAC configuration.
//-------------------------
RCC->AHB2ENR |= ( RCC_AHB2ENR_DAC1EN);
RCC->APB1ENR1 |= (RCC_APB1ENR1_TIM6EN);
RCC->AHB1ENR |= RCC_AHB1ENR_DMA1EN | RCC_AHB1ENR_DMAMUX1EN;
// https://community.st.com/t5/stm32-mcus-products/stm32g431kb-dac-dma-not-working/td-p/251096/page/2
if( dac_channel == 0 ) {
DMAMUX1_Channel2->CCR &= ~DMAMUX_CxCR_DMAREQ_ID;
DMAMUX1_Channel2->CCR |= ( 0x6 << DMAMUX_CxCR_DMAREQ_ID_Pos );
//DMAMUX1_Channel2->CCR |= DMA_REQUEST_DAC1_CHANNEL1; // DAC1 CH1 6
DMA1_Channel3->CCR &= ~DMA_CCR_EN; // It must not be written when the channel is enabled
DMA1_Channel3->CCR = DMA_CCR_MINC // memory increment
| DMA_CCR_DIR // memory to peripheral
//| ( 0x2 << DMA_CCR_PSIZE_Pos ) // 32 bit
| DMA_CCR_CIRC; // curcular mode
//
DMA1_Channel3->CNDTR = len; // how many data to transfer
DMA1_Channel3->CMAR = (uint32_t)&wave[ 0 ];
DMA1_Channel3->CPAR = (uint32_t)&( DAC->DHR8R1 ); // destination address - DAC 8 bit output register
DMA1_Channel3->CCR |= DMA_CCR_EN;
}
else {
DMAMUX1_Channel3->CCR &= ~DMAMUX_CxCR_DMAREQ_ID;
DMAMUX1_Channel3->CCR |= ( 0x7 << DMAMUX_CxCR_DMAREQ_ID_Pos );
//DMAMUX1_Channel3->CCR |= DMA_REQUEST_DAC1_CHANNEL2; // DAC1 CH2 7
DMA1_Channel4->CCR &= ~DMA_CCR_EN;
DMA1_Channel4->CCR = DMA_CCR_MINC // memory increment
| DMA_CCR_DIR // memory to peripheral
//| ( 0x2 << DMA_CCR_PSIZE_Pos ) // 32 bit
| DMA_CCR_CIRC; // curcular mode
//
DMA1_Channel4->CNDTR = len; // how many data to transfer
DMA1_Channel4->CMAR = (uint32_t)wave;
DMA1_Channel4->CPAR = (uint32_t)&( DAC->DHR8R2 ); // destination address - DAC 8 bit output register
}
//-------------------------------------------------
// https://vivonomicon.com/2019/07/05/bare-metal-stm32-programming-part-9-dma-megamix/
TIM6->CR1 &= ~TIM_CR1_CEN;
TIM6->ARR = SystemCoreClock / ( freq * len ) - 1;
TIM6->CR2 &= ~TIM_CR2_MMS;
TIM6->CR2 |= 2 << TIM_CR2_MMS_Pos; // the update event is selected as trigger output
TIM6->CR1 |= TIM_CR1_CEN;
//-----------------------------------------------------------------------
pinMode( pin, OUTPUT );
switch( pin ) {
case PA4 :
GPIOA->MODER &= ~( 0x3 << ( 4 * 2 ) );
GPIOA->MODER |= ( 0x3 << ( 4 * 2 ) );
//GPIOA->MODER |= GPIO_MODER_MODE4;
dac_channel = 0;
DAC->CR &= ~( DAC_CR_EN1 | DAC_CR_CEN1 ); // for register access
DAC->MCR &= ~DAC_MCR_MODE1;
DAC->CR |= DAC_CR_TEN1; // trigger enable
DAC->CR |= DAC_CR_DMAEN1; // DMA 사용
DAC->CR &= ~DAC_CR_TSEL1; // DAC channel1 trigger selection
DAC->CR |= DAC_TRIGGER_T6_TRGO; // DAC_TRIGGER_T6_TRGO
DAC->CR |= DAC_CR_EN1;
while( ( DAC->SR & DAC_SR_DAC1RDY ) == 0 );
break;
case PA5 :
GPIOA->MODER &= ~( 0x3 << ( 5 * 2 ) );
GPIOA->MODER |= ( 0x3 << ( 5 * 2 ) );
//GPIOA->MODER |= GPIO_MODER_MODE5;
dac_channel = 1;
DAC->CR &= ~( DAC_CR_EN2 | DAC_CR_CEN2 ); // for register access
DAC->MCR &= ~DAC_MCR_MODE2;
DAC->CR |= DAC_CR_TEN2; // trigger enable
DAC->CR |= DAC_CR_DMAEN2; // DMA 사용
DAC->CR &= ~DAC_CR_TSEL2; // DAC channel2 trigger selection
DAC->CR |= DAC_TRIGGER_T6_TRGO; // DAC_TRIGGER_T6_TRGO 7
DAC->CR |= DAC_CR_EN2;
while( ( DAC->SR & DAC_SR_DAC2RDY ) == 0 );
break;
default : return false;
}

return true;
}

[waclawek.jan]

"Manually" filled DAC (in a loop, using loopdelay) works?

TIM6_CNT, DMA_NDTR do change when observed in debugger?

Read out and check/post content of TIM, DMA, DAC and relevant GPIO registers.

JW

[AVoig.1]

I am having the same problem with STM32G431KBU6. I think this microcontroller don´t work with DMA, to reach the callbacks, i try a lot of ways and nothing. Really bad.

[waclawek.jan]

Please don't hijack old threads - start a new one, describing your HW and SW, expected behaviour and how observed one departs from it, and attach readout values from registers of relevant peripherals.

JW