STM32F103ADC采样采不到单个或多个周期性正弦波（50Khz~200Khz...

1万 · 2021-2-24 10:01

ADC采样连续正玄波（50Khz~200Khz），液晶显示（400Vpp）是正常的。输入50KHZ波数为1或者其他个数＜170个（周期大于5ms）液晶显示为0，实际上ADC可以采到几个值。波数大于170个可以显示（400vpp）。假如采样信号给2khz输入10个波就可以了，正常显示了。之前做过采单个或者几个波是可以正常显示的。这次就不行了，板子基本没变。

采样程序
#include "AD.h"
#include "STM32f10x_it.h"
#include "delay.h"

void ADInit(void) {
      ADC_InitTypeDef ADC_InitStructure;
      GPIO_InitTypeDef GPIO_InitStructure;

      RCC_APB2PeriphclockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_ADC1, ENABLE);

      RCC_ADCCLKConfig(RCC_PCLK2_Div2);
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
      GPIO_Init(GPIOC, &GPIO_InitStructure);

      ADC_DeInit(ADC1);

      ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
      ADC_InitStructure.ADC_ScanConvMode = DISABLE;
      ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
      ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
      ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
      ADC_InitStructure.ADC_NbrOfChannel = 1;
      ADC_Init(ADC1, &ADC_InitStructure);
      ADC_Cmd(ADC1, ENABLE);
      ADC_ResetCalibration(ADC1);
      while (ADC_GetResetCalibrationStatus(ADC1));
      ADC_StartCalibration(ADC1);
      while (ADC_GetCalibrationStatus(ADC1));
}
u16 GetAdc(u8 type,u8 ch) {
      if (type == 0) {
            ADC_RegularChannelConfig(ADC1, ch, 1, ADC_SampleTime_28Cycles5);
      } else {
            ADC_RegularChannelConfig(ADC1, ch, 1, ADC_SampleTime_7Cycles5);
      }

      ADC_SoftwareStartConvCmd(ADC1, ENABLE); //ʹ��ָ��ADC1��ת��

      while (!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC)); //�ȴ�ת��

      return ADC_GetConversionValue(ADC1); //��һ��ADC1��ת��
}

void BubbleSort(u16 *arr, u16 size) {
      int i, j, tmp;
      for (i = 0; i < size - 1; i++) {
            for (j = 0; j < size - i - 1; j++) {
                     if (arr[j] > arr[j + 1]) {
                              tmp = arr[j];
                              arr[j] = arr[j + 1];
                              arr[j + 1] = tmp;
                     }
            }
      }
}

u16 FindAdcMaxValue(u16 *arr, u16 size){
      int i = 0;
      u16 AdcMaxValue;
      AdcMaxValue = arr[0];
      for(i = 1; i < size - 1; i++){
            if(arr > AdcMaxValue){
               AdcMaxValue = arr;
            }
      }
      return AdcMaxValue;
}
u16 GetAdcMaxValue(u8 type,u8 ch) {
      u16 i = 0;
      u16 j = 0;
      u16 admaxValue = 0;
      u16 adValue = 0;
      static u16 arrayV[200] = {0};
      static u16 arrayI[200] = {0};
      u16 a = 0;
      static u16 timeOutCnt
            = 0;

      if (type == 0) {
            while (i < 200) {
                     adValue = GetAdc(type,ch);
                     if (adValue > 200) {
                              arrayV = adValue;
                              i++;
                              timeOutCnt = 0;
                     } else {
                              timeOutCnt++;
                              if (timeOutCnt > 200) {
                                    for (j=0;j<200;j++) {
                                                      arrayV[j] = 0;
                                    }
                                    timeOutCnt = 0;
                                    break;
                              }
                     }
            }
            admaxValue = FindAdcMaxValue(arrayV,200);
      } else {
            while (i < 200) {
                     adValue = GetAdc(type,ch);
                     if (adValue > 40) {
                              arrayI = adValue;
                              i++;
                              timeOutCnt = 0;
                     } else {
                              timeOutCnt++;
                              if (timeOutCnt > 200) {
                                    timeOutCnt = 0;
                                    break;
                              }
                     }
            }

            admaxValue = FindAdcMaxValue(arrayI,200);
      }
      //BubbleSort(array,200);
      //return array[199];
      timeOutCnt = 0;
      if (admaxValue > 1600) {
            a = 10;
      }
      return admaxValue;
}
void ADTest(void)
{
      while (1)
      {
            //UART1SendByte(GetADV());
            DelayNmS(200);
      }
}

这是50K连续波显示和仿真看到的采样数据

这是50KHZ发送5个正弦波(周期5ms）