电压采样

2万 · 2014-10-30 11:39

用AD1的通道15对温度传感器的上电压进行采样，通过WATCH窗口查看AD转换的结果发现采样的值总是一个大的范围的抖动,百思不得其解  温度传感的部分的电路如下：AD部分的驱动如下：/****************ADC配置函数******************************/
/*********************************************************/
void ConfigADC()
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE);    //打开ADC1的时钟
ADC_InitStruct.ADC_Mode=ADC_Mode_Independent;                   /*!< Configures the ADC to operate in independent or
                                                   dual mode.
                                                   This parameter can be a value of @ref ADC_mode */
ADC_InitStruct.ADC_ScanConvMode=DISABLE;          /*!< Specifies whether the conversion is performed in
                                                   Scan (multichannels) or Single (one channel) mode.
                                                   This parameter can be set to ENABLE or DISABLE */
ADC_InitStruct.ADC_ContinuousConvMode=DISABLE;    /*!< Specifies whether the conversion is performed in
                                                      Continuous or Single mode.
                                                      This parameter can be set to ENABLE or DISABLE. */
ADC_InitStruct.ADC_ExternalTrigConv=ADC_ExternalTrigConv_None;       /*!< Defines the external trigger used to start the analog
                                                      to digital conversion of regular channels. This parameter
                                                      can be a value of @ref ADC_external_trigger_sources_for_regular_channels_conversion */
ADC_InitStruct.ADC_DataAlign=ADC_DataAlign_Right;                /*!< Specifies whether the ADC data alignment is left or right.
                                                      This parameter can be a value of @ref ADC_data_align */
ADC_InitStruct.ADC_NbrOfChannel=1;                   /*!< Specifies the number of ADC channels that will be converted
                                                      using the sequencer for regular channel group.
                                                      This parameter must range from 1 to 16. */
ADC_Init(ADC1,&ADC_InitStruct);
ADC_RegularChannelConfig(ADC1,ADC_Channel_11,1,ADC_SampleTime_239Cycles5);
ADC_Cmd(ADC1,ENABLE);
//初始化时开启一次自动校准
ADC_ResetCalibration(ADC1);
   while(ADC_GetResetCalibrationStatus(ADC1));
   // Start ADC1 calibaration
   ADC_StartCalibration(ADC1);
   // Check the end of ADC1 calibration
   while(ADC_GetCalibrationStatus(ADC1));
}

AD的时钟为12M RCC_PCLK2Config(RCC_HCLK_Div1);
RCC_ADCCLKConfig(RCC_PCLK2_Div6);
通道11的对应端口为PC1：GPIO_InitStruct.GPIO_Pin=GPIO_Pin_1;
GPIO_InitStruct.GPIO_Speed=GPIO_Speed_10MHz;
GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AIN;    //模拟输入
GPIO_Init(GPIOC,&GPIO_InitStruct);
读取AD结果int16_t TemperSample() //要关闭外部中断，启动一次AD转换，计算出温度值
{
uint16_t T_Vaule,i;

// ADC_Cmd(ADC1,ENABLE);
ADC_SoftwareStartConvCmd(ADC1,ENABLE); //开启一次软件触发AD
while(!ADC_GetFlagStatus(ADC1,ADC_FLAG_EOC));
T_Vaule=ADC_GetConversionValue(ADC1);  //取回转换值
return(T_Vaule);
}