stm32 LL库 dma模式采集ADC值

cdft

STM32L4采用DMA模式采样ADC值，adc_value一直是最低字节变化【差不多在0x00000040--0x00000060之间变化】是什么原因？
volatile uint32_t adc_value;

void MX_ADC_Init(void)
{
  LL_ADC_REG_InitTypeDef ADC_REG_InitStruct;
  LL_ADC_InitTypeDef ADC_InitStruct;
  LL_GPIO_InitTypeDef GPIO_InitStruct;
       
        LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);
        LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
        LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOC);
       
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_ADC);
        LL_RCC_SetADCClockSource(LL_RCC_ADC_CLKSOURCE_SYSCLK);
       

  GPIO_InitStruct.Pin = LL_GPIO_PIN_0 ;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ANALOG;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
       
        LL_GPIO_EnablePinAnalogControl(GPIOB,        LL_GPIO_PIN_0);
       
  /* ADC Init */
  LL_DMA_SetPeriphRequest(DMA1, LL_DMA_CHANNEL_1, LL_DMA_REQUEST_0);

  LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_1, LL_DMA_DIRECTION_PERIPH_TO_MEMORY);

  LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PRIORITY_HIGH);

  LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_MODE_CIRCULAR);//

  LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PERIPH_NOINCREMENT);

  LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PERIPH_NOINCREMENT);

  LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PDATAALIGN_HALFWORD);

  LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PDATAALIGN_HALFWORD);

        LL_DMA_ConfigAddresses(DMA1,LL_DMA_CHANNEL_1,(uint32_t)&(ADC1->DR),(uint32_t)&adc_value,LL_DMA_DIRECTION_PERIPH_TO_MEMORY);
  LL_DMA_SetDataLength(DMA1,LL_DMA_CHANNEL_1,1);


  LL_ADC_REG_SetSequencerRanks(ADC1, LL_ADC_REG_RANK_1,LL_ADC_CHANNEL_15);
       
  ADC_REG_InitStruct.TriggerSource = LL_ADC_REG_TRIG_SOFTWARE;
  ADC_REG_InitStruct.SequencerDiscont = LL_ADC_REG_SEQ_DISCONT_DISABLE;
  ADC_REG_InitStruct.ContinuousMode = LL_ADC_REG_CONV_CONTINUOUS;
  ADC_REG_InitStruct.DMATransfer = LL_ADC_REG_DMA_TRANSFER_UNLIMITED;
  ADC_REG_InitStruct.Overrun = LL_ADC_REG_OVR_DATA_PRESERVED;
        //ADC_REG_InitStruct.SequencerLength = LL_ADC_REG_SEQ_SCAN_DISABLE;
  LL_ADC_REG_Init(ADC1, &ADC_REG_InitStruct);

  LL_ADC_SetChannelSamplingTime(ADC1, LL_ADC_CHANNEL_11, LL_ADC_SAMPLINGTIME_47CYCLES_5);
  LL_ADC_SetOverSamplingScope(ADC1,LL_ADC_OVS_DISABLE );//LL_ADC_OVS_GRP_REGULAR_CONTINUED

        LL_ADC_CommonInitTypeDef ADC_CommonInitStruct;
        ADC_CommonInitStruct.CommonClock = LL_ADC_CLOCK_ASYNC_DIV2;
        ADC_CommonInitStruct.Multimode = LL_ADC_MULTI_INDEPENDENT;
//        ADC_CommonInitStruct.MultiDMATransfer = LL_ADC_MULTI_REG_DMA_EACH_ADC;
//        ADC_CommonInitStruct.MultiTwoSamplingDelay = LL_ADC_MULTI_TWOSMP_DELAY_12CYCLES;
        LL_ADC_CommonInit(__LL_ADC_COMMON_INSTANCE(ADC1), &ADC_CommonInitStruct);
       
  ADC_InitStruct.Resolution = LL_ADC_RESOLUTION_12B;
  ADC_InitStruct.DataAlignment = LL_ADC_DATA_ALIGN_RIGHT;
  ADC_InitStruct.LowPowerMode = LL_ADC_LP_MODE_NONE;
  LL_ADC_Init(ADC1, &ADC_InitStruct);
       
        LL_ADC_DisableIT_EOC(ADC1);
  LL_ADC_DisableIT_EOS(ADC1);       
        LL_ADC_SetChannelSingleDiff(ADC1, LL_ADC_CHANNEL_15, LL_ADC_SINGLE_ENDED);
       
        LL_VREFBUF_Enable();
        LL_VREFBUF_DisableHIZ();
        LL_VREFBUF_SetVoltageScaling(LL_VREFBUF_VOLTAGE_SCALE1);
        while(!LL_VREFBUF_IsVREFReady());       
       
        LL_ADC_DisableDeepPowerDown(ADC1);
  LL_ADC_EnableInternalRegulator(ADC1);
  int wait_loop_index = ((LL_ADC_DELAY_INTERNAL_REGUL_STAB_US * (SystemCoreClock / (100000 * 2))) / 10);
  while(wait_loop_index != 0)
  {
    wait_loop_index--;
  }  
       
        LL_ADC_StartCalibration(ADC1, LL_ADC_SINGLE_ENDED);
        while (LL_ADC_IsCalibrationOnGoing(ADC1) != 0)
        {}
       
        DMA_ADC_On();       
}


void DMA_ADC_On(void)
{
        LL_ADC_Enable(ADC1);
        while(!LL_ADC_IsActiveFlag_ADRDY(ADC1));
        LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_1);
        LL_ADC_REG_StartConversion(ADC1);
}

void board_dma_init(void)
{
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);
       
  NVIC_SetPriority(DMA1_Channel1_IRQn, 5);
  NVIC_EnableIRQ(DMA1_Channel1_IRQn);

}

cdft

只在主循环前初始化board_dma_init和MX_ADC_Init，然后打印adc_value的值，一直不对

eric2013

先把句柄做0初始化：
LL_ADC_InitTypeDef ADC_InitStruct;
其它问题不清楚了。

cdft

eric2013 发表于 2020-1-13 12:52
先把句柄做0初始化：
LL_ADC_InitTypeDef ADC_InitStruct;
其它问题不清楚了。

void MX_ADC_Init(void)
{
        LL_ADC_InitTypeDef ADC_InitStruct;
        LL_GPIO_InitTypeDef GPIO_InitStruct;
  LL_ADC_REG_InitTypeDef ADC_REG_InitStruct;
       
  ADC_InitStruct.Resolution = LL_ADC_RESOLUTION_12B;
  ADC_InitStruct.DataAlignment = LL_ADC_DATA_ALIGN_RIGHT;
  ADC_InitStruct.LowPowerMode = LL_ADC_LP_MODE_NONE;
  LL_ADC_Init(ADC1, &ADC_InitStruct);


是这样么？读数最低字节在变化但是还是不大于0x00000100;

eric2013

cdft 发表于 2020-1-13 13:20
void MX_ADC_Init(void)
{
        LL_ADC_InitTypeDef ADC_InitStruct;

LL_ADC_InitTypeDef ADC_InitStruct = {0};