Transferring ADC result via eDMA (KSDK 2.0)

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Transferring ADC result via eDMA (KSDK 2.0)

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mopfi
Contributor I

I'm pretty new to all this. Just started developing for Kinetis with KSDK 2.0 and have some problems. I think I don't understand every detail completely.

I want to start one ADC conversion with software trigger. After finished conversion the result should be copied to SRAM. I used the examples for MemoryToMemory copy and the interrupt example for ADC.

Both alone work fine, but when I want to combine this the callback is never fired. I think the problem might be my ADC initialisation.

#define ADC_BASEADDR                         (ADC1)
#define ADC_CHANNEL_GROUP               (0U)
#define ADC_USER_CHANNEL               (18U)
#define ADC_DR                                   (ADC_BASEADDR->R[ADC_CHANNEL_GROUP])

#define DMA_BASEADDR                         (DMA0)
#define DMA_CHANNEL                         (3)

#define BUFFER_SIZE                         (8)
static void initADC(void) {
     adc16_config_t adc16ConfigStruct;

     ADC16_GetDefaultConfig(&adc16ConfigStruct);
     ADC16_Init(ADC_BASEADDR, &adc16ConfigStruct);
     ADC16_EnableHardwareTrigger(ADC_BASEADDR, true);
     ADC16_EnableDMA(ADC_BASEADDR, true);

     g_adc16ChannelConfigStruct.channelNumber = ADC_USER_CHANNEL;
     g_adc16ChannelConfigStruct.enableInterruptOnConversionCompleted = false;
}
static void initDMA(void) {
     memset(adc_mem, 0x55, sizeof(adc_mem));

     /* Configure DMAMUX */
     DMAMUX_Init(DMAMUX0);
    DMAMUX_SetSource(DMAMUX0, DMA_CHANNEL, 41);
     DMAMUX_EnableChannel(DMAMUX0, DMA_CHANNEL);

     edma_config_t edma_config;
    edma_transfer_config_t transfer_config;

     /* Init the eDMA driver */
     EDMA_GetDefaultConfig(&edma_config);
     EDMA_Init(DMA_BASEADDR, &edma_config);
     EDMA_CreateHandle(&edma_handle, DMA_BASEADDR, DMA_CHANNEL);
     EDMA_SetCallback(&edma_handle, dmaCallback, NULL);
     EDMA_PrepareTransfer(&transfer_config, &ADC_DR, 2, adc_mem, 2, 1, 1, kEDMA_PeripheralToMemory);
     
   if (EDMA_SubmitTransfer(&edma_handle, &transfer_config) == kStatus_Success) {
          PRINTF("\r\nEDMA Submit Transfer: Success\r\n");
     } else {
          PRINTF("\r\nEDMA Submit Transfer: Failed\r\n");
     }

     EDMA_StartTransfer(&edma_handle);
}
int main(void) {
     uint8_t msg = ' ';

     BOARD_InitPins();
     BOARD_BootClockRUN();
     BOARD_InitDebugConsole();

     PRINTF("\r\nPress any key to start demo.\r\n");
     GETCHAR();
    PRINTF("\r\nInitializing ADC\r\n");
     initADC();
     PRINTF("\r\nInitializing DMA\r\n");
     initDMA();

     while (1) {
          PRINTF("Destination Buffer:\r\n");
          int i = 0;
          for (i = 0; i < BUFFER_SIZE; i++) {
               PRINTF("%d\t", adc_mem[i]);
          }

          ADC16_SetChannelConfig(ADC_BASEADDR, ADC_CHANNEL_GROUP, &g_adc16ChannelConfigStruct);
      
      
          while (dmadone != true)
               ;
      
          PRINTF("\r\nDMA DONE\r\n");
     }
}
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450 Views
mopfi
Contributor I

Ok, now I got it working. Wasn't so wrong.

Here is the code that has to be changed.

static void initADC(void) {
  ...

  ADC16_EnableHardwareTrigger(ADC_BASEADDR, false);
  ADC16_EnableDMA(ADC_BASEADDR, true);

  ...
}

static void initDMA(void) {
  ...

  EDMA_PrepareTransfer(&transfer_config, &ADC_DR, 2, adc_mem, 2, 2, 2, kEDMA_PeripheralToMemory);

  ...
}

I had to change the size to 2 for bytesEachRequest and transferBytes. Now its copying my one byte. Smiley Happy

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