STM32F103捕获功能实现超声波测距程序

ID:82220 · 发表于 2020-11-7 20:13

学习stm32的捕获功能，能够实现2米内精确测距。
#include "stm32f10x.h"
#include "input_capture.h"
#include <stdio.h>

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
void delay_us(u16 time)
{
      u16 i;
      for(i=0;i<time*8;i++);
}

/* Private functions ---------------------------------------------------------*/
void start_measor_init(void)
{
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
      GPIO_InitTypeDef GPIO_InitStruct;
      GPIO_InitStruct.GPIO_Mode=GPIO_Mode_Out_PP;
      GPIO_InitStruct.GPIO_Pin=GPIO_Pin_1;
      GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz;
      GPIO_Init(GPIOA, &GPIO_InitStruct);
      GPIO_ResetBits(GPIOA, GPIO_Pin_1);
}
void start_measor_start(void)
{

      TIM_CCxCmd(TIM2, TIM_Channel_1, TIM_CCx_Enable);
      GPIO_SetBits(GPIOA, GPIO_Pin_1);
      delay_us(40);
      GPIO_ResetBits(GPIOA, GPIO_Pin_1);


}
/**
  * @brief  Main program.
  * @param  None
  * @retval None
  */
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
      start_measor_init();
      input_capture_init();
            flag=0;
  while (1)
  {
      unsigned i;
            i++;
      if(i%100==0)
      {
               start_measor_start();
      }
  }
}

#include "input_capture.h"
#include "stm32f10x_tim.h"
unsigned char flag;
float distance ;
void input_capture_init(void)
{


      RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

      GPIO_InitTypeDef GPIO_InitStruct;
      GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPD;
      GPIO_InitStruct.GPIO_Pin=GPIO_Pin_0;
      GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz;
      GPIO_Init(GPIOA, &GPIO_InitStruct);

      TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
      TIM_TimeBaseInitStruct.TIM_ClockDivision=TIM_CKD_DIV1;
      TIM_TimeBaseInitStruct.TIM_CounterMode=TIM_CounterMode_Up;
      TIM_TimeBaseInitStruct.TIM_Period=65535;
      TIM_TimeBaseInitStruct.TIM_Prescaler=7199;
      TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStruct);


      TIM_ICInitTypeDef TIM_ICInitStruct;
  TIM_ICInitStruct.TIM_Channel=TIM_Channel_1;
  TIM_ICInitStruct.TIM_ICFilter=0xF;
  TIM_ICInitStruct.TIM_ICPolarity=TIM_ICPolarity_Rising;
      TIM_ICInitStruct.TIM_ICPrescaler=TIM_ICPSC_DIV1;
      TIM_ICInitStruct.TIM_ICSelection=TIM_ICSelection_DirectTI;
      TIM_ICInit(TIM2, &TIM_ICInitStruct);

      NVIC_InitTypeDef NVIC_InitStruct;
      NVIC_InitStruct.NVIC_IRQChannel=TIM2_IRQn;
      NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
      NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=2;
      NVIC_InitStruct.NVIC_IRQChannelSubPriority=2;
NVIC_Init(&NVIC_InitStruct);

      // TIM_Cmd(TIM3,ENABLE );
//TIM_CCxCmd(TIM3, TIM_Channel_1, TIM_CCx_Enable);
      //TIM_ITConfig(TIM3, TIM_IT_CC1, ENABLE);

      TIM_ITConfig(TIM2, TIM_IT_CC1, ENABLE);
      TIM_Cmd(TIM2,ENABLE );

}

void TIM2_IRQHandler(void)
{
      u16 record_rising,record_falling;

      if( TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
      {
            if(flag==1)
            {       record_falling=TIM_GetCapture1       (       TIM2       );
                     distance=(float)record_falling*340/200.0;
                     //record_rising=TIM_GetCapture1       (       TIM2       );
   flag=0;
                     TIM_OC1PolarityConfig(TIM2,TIM_ICPolarity_Rising); //CC1P=0 设置为上升沿捕获

            }
            else
            {
                     record_rising=0;
                     record_falling=0;
                     TIM_SetCounter(TIM2,0);
               TIM_OC1PolarityConfig(TIM2,TIM_ICPolarity_Falling);             //CC1P=1 设置为下降沿捕获
               flag=1;
            //

            }

      }
  TIM_ClearITPendingBit(TIM2, TIM_IT_CC1);
}

帐号		自动登录	找回密码
密码			立即注册

STM32F103捕获功能实现超声波测距程序

评分