基于STM32F103C8T6超声波测距HC-SR04源码及接线（已调）

ID:696077 · 发表于 2020-5-30 09:07

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#include "delay.h"
#include "sys.h"
#include "usart.h"
#include "led.h"
#include "key.h"
/***************************************************
大海电子专营各种电子模块，欢迎光临
硬件连接
串口1：RX PA10  TX PA9
超声波：Trig PB11 ECHG PB10
备注：以下代码非原创，只是经过修改适配成STM32F103C8T6
若侵权，请告知。

***************************************************/

//超声波硬件接口定义
#define HCSR04_PORT    GPIOB
#define HCSR04_CLK    RCC_APB2Periph_GPIOB
#define HCSR04_TRIG    GPIO_Pin_15
#define HCSR04_ECHO    GPIO_Pin_14

//超声波计数
u16 msHcCount = 0;

//定时器4设置
void hcsr04_NVIC()
{
      NVIC_InitTypeDef NVIC_InitStructure;
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

      NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);
}

//IO口初始化及其他初始化
void Hcsr04Init()
{
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(HCSR04_CLK, ENABLE);

GPIO_InitStructure.GPIO_Pin =HCSR04_TRIG;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(HCSR04_PORT, &GPIO_InitStructure);
GPIO_ResetBits(HCSR04_PORT,HCSR04_TRIG);

GPIO_InitStructure.GPIO_Pin = HCSR04_ECHO;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(HCSR04_PORT, &GPIO_InitStructure);
GPIO_ResetBits(HCSR04_PORT,HCSR04_ECHO);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

TIM_DeInit(TIM2);
TIM_TimeBaseStructure.TIM_Period = (1000-1);
TIM_TimeBaseStructure.TIM_Prescaler =(72-1);
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

TIM_ClearFlag(TIM4, TIM_FLAG_Update);
TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);
hcsr04_NVIC();
TIM_Cmd(TIM4,DISABLE);
}

//打开定时器4
static void OpenTimerForHc()
{
TIM_SetCounter(TIM4,0);
msHcCount = 0;
TIM_Cmd(TIM4, ENABLE);
}

//关闭定时器4
static void CloseTimerForHc()
{
TIM_Cmd(TIM4, DISABLE);
}

//定时器4终中断
void TIM4_IRQHandler(void)
{
if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)
{
   TIM_ClearITPendingBit(TIM4, TIM_IT_Update  );
   msHcCount++;
}
}

//获取定时器4计数器值
u32 GetEchoTimer(void)
{
u32 t = 0;
t = msHcCount*1000;
t += TIM_GetCounter(TIM4);
TIM4->CNT = 0;
delay_ms(50);
return t;
}

//通过定时器4计数器值推算距离
float Hcsr04GetLength(void )
{
u32 t = 0;
int i = 0;
float lengthTemp = 0;
float sum = 0;
while(i!=5)
{
   TRIG_Send = 1;
   delay_us(20);
   TRIG_Send = 0;
   while(ECHO_Reci == 0);
   OpenTimerForHc();
   i = i + 1;
   while(ECHO_Reci == 1);
   CloseTimerForHc();
   t = GetEchoTimer();
   lengthTemp = ((float)t/58.0);//cm
   sum = lengthTemp + sum ;

}
lengthTemp = sum/5.0;
return lengthTemp;
}

//测试主函数
int main(void)
{
      float length;
      delay_init();                   //延时函数初始化
      NVIC_Configuration();       //设置NVIC中断分组2:2位抢占优先级，2位响应优先级
      uart_init(9600);                //串口初始化为9600
      Hcsr04Init();
      printf("串口测试\r\n");

Hcsr04Init();
printf("超声波初始化成功!\n");

while(1)
      {
   length = Hcsr04GetLength();
   printf("距离为:%.3fcm\n",length);
               delay_ms(1000);
      }
}