单通道 ADC_DMA STM32F103ZET6 电压稳定，为什么获取到的AD值却不稳定，跳变很大

核子霹雳 · 发表于 2017-2-22 18:12:33

单通道 ADC_DMA STM32F103ZET6  电压稳定，为什么获取到的AD值却不稳定，跳变很大!

vu16 ADC_ConvertedValue;

void ADC1_Init(void)
{
ADC_GPIO_Init();
ADC1_DMA1_Config();
}

void ADC1_DMA1_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;
ADC_InitTypeDef ADC_InitStructure;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE );
// DMA channel1 configuration */
    DMA_DeInit(DMA1_Channel1);
    DMA_InitStructure.DMA_PeripheralBaseAddr = ADC_Adress_Value;
    DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADC_ConvertedValue;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = 1;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
    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);

    // Enable DMA channel1 //
    DMA_Cmd(DMA1_Channel1, ENABLE);

    // ADC1 configuration //
    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode = ENABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfChannel = 1;
    ADC_Init(ADC1, &ADC_InitStructure);

    // ADC1 regular channel11 configuration
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_55Cycles5);

    // Enable ADC1 DMA //
    ADC_DMACmd(ADC1, ENABLE);

    // Enable ADC1 //
    ADC_Cmd(ADC1, ENABLE);

    // Enable ADC1 reset calibaration register /
    ADC_ResetCalibration(ADC1);
    // Check the end of ADC1 reset calibration register /
    while(ADC_GetResetCalibrationStatus(ADC1));

    // Start ADC1 calibaration /
    ADC_StartCalibration(ADC1);
    // Check the end of ADC1 calibration /
    while(ADC_GetCalibrationStatus(ADC1));

    // Start ADC1 Software Conversion /
ADC_SoftwareStartConvCmd(ADC1, ENABLE);

}
//3

void ADC_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );

RCC_ADCCLKConfig(RCC_PCLK2_Div6);


GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_Init(GPIOC, &GPIO_InitStructure);

}

void Get_AdcValue(void)
{
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
while(DMA_GetFlagStatus(DMA1_FLAG_TC1) == RESET);
DMA_ClearFlag(DMA1_FLAG_TC1);
}

u16 Get_Adc_Average(u8 times)
{
u32 temp_val=0;
u8 t;
for(t=0;t<times;t++)
{
Get_AdcValue();
temp_val+= ADC_ConvertedValue;
}
return temp_val/times;
}

ADC_temp = Get_Adc_Average(10) ;

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