CODEWITHSUNDEEP
stm32wavdmadac
Erik PS
Erik PS

Reputation: 1

STM32 M4 Cortex WAV Player SD Card DMA DAC

For months I try to run a wave file 16bit 48kHz from SD Card to my DAC output via DMA.

But all I get is scary sounds. I read so many ST Electronics data sheets, but nothing solve the problem.

First I try HAL Driver, but only a sine waveform from an array worked. Not the wave file.

So I switched to Low Layer drivers for DMA, TIM6 and DAC.

Here my init source in main:

  LL_DAC_EnableDMAReq(DAC1, LL_DAC_CHANNEL_1); // enable DMA for Channel1
  LL_DAC_Enable(DAC1, LL_DAC_CHANNEL_1); //enable Channel on DAC
  LL_DMA_ConfigAddresses(DMA1, LL_DMA_STREAM_5,(uint32_t) &DAC_Buff, LL_DAC_DMA_GetRegAddr(DAC1, LL_DAC_CHANNEL_1, LL_DAC_DMA_REG_DATA_12BITS_RIGHT_ALIGNED ), LL_DMA_DIRECTION_MEMORY_TO_PERIPH ); //Speicherbereich auf den die DMA Unit zugreift definieren
  LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_5, 2);     // die beschreibung in UM1725 ist heir etwas dürftig ich hab einfach mal 16 für 2byte genommen
  LL_DMA_EnableIT_HT(DMA1,LL_DMA_STREAM_5);     // Halb Transfer Interrupt für Sream5 aktivieren
  LL_DMA_EnableIT_TC(DMA1,LL_DMA_STREAM_5);      // Complet Transfer Interrupt für Sream5 aktivieren
  LL_DAC_EnableTrigger(DAC1, LL_DAC_CHANNEL_1);  // ohne geht garnix, aber wenn an muss man __disable_irq machen
  LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_5);    //Stream5 DAC1 Starten

My source to read the file worked:

char wave_playback(const char *FileName)
{
  FRESULT res;
  FIL file;
  UINT cnt;
uint32_t filesize;

  res = f_open( &file, FileName, FA_READ );   //file oeffne
  if(res) return 1;
filesize= f_size(&file);
  res = f_lseek(&file,0x2c);                  // WAV head  überspringen
//  filesize=filesize-0x2c;
  if(res) return 2;
 f_read (&file,&DAC_Buff[0],512,&cnt);       //beider 256 Buffer befüllen
 //filesize=filesize-512;
  if(res) return 3;

 __disable_irq();

  //TIM6->CR1 |= TIM_CR1_CEN;
 LL_TIM_EnableCounter(TIM6);                // Timer 6 der DMA triggert starten

  while(1)
  {
     volatile ITStatus it_st;
         it_st = RESET;
     while(it_st == RESET) {   //auf Flag für halben Transfer warten
         it_st = LL_DMA_IsActiveFlag_HT5(DMA1);
         //it_st = READ_BIT(DMA1->HISR ,DMA_HISR_HTIF5);
     }
     f_read (&file,&DAC_Buff[0],256,&cnt);      //unteren buffer befüllen
     LL_DMA_ClearFlag_HT5(DMA1);                // half transfer flag (stream5) löschen
    // DMA1->HISR |= DMA_HISR_HTIF5;
    // filesize=filesize-256;
     if(cnt<256)break;                        //wenn das ende des files erreicht while verlassen

     it_st = RESET;
     while(it_st == RESET) {   ////auf Flag für kompletten Transfer warten
     it_st = LL_DMA_IsActiveFlag_TC5(DMA1);
     //it_st = READ_BIT(DMA1->HISR ,DMA_HISR_TCIF5);
     }
     f_read (&file,&DAC_Buff[256],256,&cnt);  //oberen buffer befüllen
     LL_DMA_ClearFlag_TC5(DMA1);  //complet transfer flag (stream5) löschen
     //DMA1->HISR |= DMA_HISR_TCIF5;
    // filesize=filesize-256;
     if(cnt<256)break;                        //wenn das ende des files erreicht while verlassen
  }

  //TIM6->CR1 &= ~TIM_CR1_CEN;                  // Roh Kommando Timer 6 der DMA triggert stoppen
  LL_TIM_DisableCounter(TIM6);                  // Timer 6 der DMA triggert stoppen

  f_close(&file);                             //file stream beenden

  return 0;                                   //bei wenn i.O. 0 zurueck geben
}

I checked twice the wave files on the SD card (16bit 48kHz) But the sound is scary and I don't understand why.

Then I try it again with HAL Drivers but there nothing works so I switch back to LL Drivers.

What did I do wrong? Dose anybody know it?

Upvotes: 0

Views: 2052

Answers (1)

jdbrinton
jdbrinton

Reputation: 1

Likely you have a bit or byte endian issue in the data you're playing. Try switching to 8-bit mode:

LL_DMA_SetPeriphAddress(DMA1, LL_DMA_STREAM_5, LL_DAC_DMA_GetRegAddr(DAC1, LL_DAC_CHANNEL_1, LL_DAC_DMA_REG_DATA_8BITS_RIGHT_ALIGNED));
LL_DMA_SetPeriphSize(DMA1, LL_DMA_STREAM_5, LL_DMA_MDATAALIGN_BYTE);
LL_DMA_SetMemorySize(DMA1, LL_DMA_STREAM_5, LL_DMA_MDATAALIGN_BYTE);

Upvotes: -1

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