[应用相关] STM32 ADC DMA数据不稳定的解决方案

#define ADC1_DR_Address            0x40012440

//对应需要检测的ADC通道个数

#define ADC_DMA_BUFFER_SIZE     2



//按照通道顺序依次存放得到的ADC值

__IO uint16_t RegularConvData_Tab[ADC_DMA_BUFFER_SIZE] = {0, 0};



/**

  * [url=home.php?mod=space&uid=247401]@brief[/url]  DMA channel1 configuration

  * @param  None

  * @retval None

  */

void DMA_Config(void)

{

    DMA_InitTypeDef   DMA_InitStructure;

    /* DMA1 clock enable */

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);



    /* DMA1 Channel1 Config */

    DMA_DeInit(DMA1_Channel1);

    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address;

    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RegularConvData_Tab;

    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;

    DMA_InitStructure.DMA_BufferSize = ADC_DMA_BUFFER_SIZE;

    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;

    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;

    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;

    DMA_InitStructure.DMA_Priority = DMA_Priority_High;

    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel1, &DMA_InitStructure);

    /* DMA1 Channel1 enable */

    DMA_Cmd(DMA1_Channel1, ENABLE);

}



void ADC_DMA_Config(void)

{

    ADC_InitTypeDef     ADC_InitStructure;

    GPIO_InitTypeDef    GPIO_InitStructure;



    DMA_Config();



    /* ADC1 DeInit */

    ADC_DeInit(ADC1);

    /* ADC1 Periph clock enable */

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);



    /* Configure ADC Channel11 and channel10 as analog input */

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;

    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;



    RCC_AHBPeriphClockCmd(P_N_TEST_CLK, ENABLE);

    GPIO_InitStructure.GPIO_Pin = P_N_TEST_PIN ;

    GPIO_Init(P_N_TEST_PORT, &GPIO_InitStructure);



    RCC_AHBPeriphClockCmd(DC5V_TEST_CLK, ENABLE);

    GPIO_InitStructure.GPIO_Pin = DC5V_TEST_PIN ;

    GPIO_Init(DC5V_TEST_PORT, &GPIO_InitStructure);



    /* Initialize ADC structure */

    ADC_StructInit(&ADC_InitStructure);



    /* Configure the ADC1 in continuous mode withe a resolution equal to 12 bits  */

    ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;

    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;

    ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;

    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;

    ADC_InitStructure.ADC_ScanDirection = ADC_ScanDirection_Upward;

    ADC_Init(ADC1, &ADC_InitStructure);



    ADC_ChannelConfig(ADC1, DC5V_TEST_channel,ADC_SampleTime_239_5Cycles);

    ADC_ChannelConfig(ADC1, P_N_TEST_channel, ADC_SampleTime_239_5Cycles);



    /* ADC Calibration */

    ADC_GetCalibrationFactor(ADC1);



    /* ADC DMA request in circular mode */

    ADC_DMARequestModeConfig(ADC1, ADC_DMAMode_Circular);



    /* Enable ADC_DMA */

    ADC_DMACmd(ADC1, ENABLE);



    /* Enable the ADC peripheral */

    ADC_Cmd(ADC1, ENABLE);



    /* Wait the ADRDY flag */

    while (!ADC_GetFlagStatus(ADC1, ADC_FLAG_ADRDY));



    /* ADC1 regular Software Start Conv */

    ADC_StartOfConversion(ADC1);

    

}

/**

  * @brief  DMA channel1 configuration

  * @param  None

  * @retval None

  */

void DMA_Config(void)

{

    DMA_InitTypeDef   DMA_InitStructure;

    NVIC_InitTypeDef  NVIC_InitStructure;

    /* DMA1 clock enable */

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);



    /* DMA1 Channel1 Config */

    DMA_DeInit(DMA1_Channel1);

    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address;

    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RegularConvData_Tab;

    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;

    DMA_InitStructure.DMA_BufferSize = ADC_DMA_BUFFER_SIZE;

    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;

    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;

    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;

    DMA_InitStructure.DMA_Priority = DMA_Priority_High;

    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel1, &DMA_InitStructure);

    /* DMA1 Channel1 enable */

    DMA_Cmd(DMA1_Channel1, ENABLE);

    

    /* Enable the DMA1 Interrupt */

    NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel1_IRQn;

    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;

    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&NVIC_InitStructure);

    

    /* DMA1 interrupt */

    DMA_ITConfig(DMA1_Channel1,DMA_IT_TC,ENABLE);

}

//ADC DMA数据传输完成

void DMA1_Channel1_IRQHandler(void)

{

    /* Check the status of the specified DMAy flag */

    if ((DMA1->ISR & DMA1_FLAG_TC1) != (uint32_t)RESET)

    {

        ADC_DMA_INTERRUPT_HANDLER();

        //清除标志位

        DMA1->IFCR = DMA1_FLAG_TC1;

    }

}



void ADC_DMA_INTERRUPT_HANDLER(void)

{

    u8 i;

    static u8  times=0;

    static u16 buffer[ADC_DMA_BUFFER_SIZE];

    for (i=0;i<ADC_DMA_BUFFER_SIZE;i++) {

        buffer[i] += RegularConvData_Tab[i];

    }

    if (++times >= 8) { //取8次平均值

        for (i=0;i<ADC_DMA_BUFFER_SIZE;i++) {

            CalAverConvData_Tab[i] = buffer[i]>>3;

            buffer[i] = 0; //清零

        }

        times = 0;

    }

}