HC-SR04超声波模块驱动（STM32）

一、前期准备

单片机：STM32F103C8T6

开发环境：MDK5.14

库函数：标准库V3.5

HC-SR04模块：淘宝有售

二、实验效果

三、驱动原理

触发信号Tirig维持10Us以上的高电平即可等待Echo的返回，这里是用EXTI检测俩个跳变信号，去打开和关闭定时器，最后一次测量计算结果后清除定时器计时，并等待下一个循环开始。需要完整工程或者有问题的请加QQ：1002521871，验证：呵呵。

四、驱动代码

US-020.h

#ifndef __US_020_H__

#define __US_020_H__

#include "stm32f10x.h"

#include "gpio.h"

#include "delay.h"

#define Trig PAout(0)

#define Trig_Pin GPIO_Pin_0

#define Trig_Port GPIOA

#define Trig_CLKLine RCC_APB2Periph_GPIOA

#define Echo PAin(1)

#define Echo_Pin GPIO_Pin_1

#define Echo_Port GPIOA

#define Echo_CLKLine RCC_APB2Periph_GPIOA

extern uint32_t US_Count;

extern void US_020Configuration(void);

extern void US_SendStartSignal(void);

extern float US_DataConversion(uint32_t *count);

#endif

US-020.c

#include "US-020.h"

uint32_t US_Count = 0;

void US_020Configuration(void)

{

GPIO_InitTypeDef    GPIO;

    NVIC_InitTypeDef MyNVIC;

EXTI_InitTypeDef MyEXTI;

    //Enable APB2 Bus

    RCC_APB2PeriphClockCmd(Trig_CLKLine | Echo_CLKLine, ENABLE);

    //Register IO 

    GPIO.GPIO_Pin   = Trig_Pin;

    GPIO.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO.GPIO_Mode  = GPIO_Mode_Out_PP;

    GPIO_Init(Trig_Port, &GPIO);

Trig = 0;

//Register IO 

    GPIO.GPIO_Pin   = Echo_Pin;

    GPIO.GPIO_Mode  = GPIO_Mode_IN_FLOATING;

    GPIO_Init(Echo_Port, &GPIO);

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置中断优先级组为1，优先组(可设0～4位)

MyNVIC.NVIC_IRQChannel = EXTI1_IRQn; //设置中断向量号

MyNVIC.NVIC_IRQChannelPreemptionPriority = 0; //设置抢先优先级

MyNVIC.NVIC_IRQChannelSubPriority = 1; //设置响应优先级

MyNVIC.NVIC_IRQChannelCmd = ENABLE; //使能NVIC

NVIC_Init(&MyNVIC);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource1);

MyEXTI.EXTI_Line = EXTI_Line1;

MyEXTI.EXTI_Trigger = EXTI_Trigger_Rising_Falling;

MyEXTI.EXTI_Mode = EXTI_Mode_Interrupt;

MyEXTI.EXTI_LineCmd = ENABLE;

EXTI_Init(&MyEXTI);

}

void US_SendStartSignal(void)

{

Trig = 1;

DelayUs(20);

Trig = 0;

}

float US_DataConversion(uint32_t *count)

{

float result = 0;

result = (float)((float)(*count * 340) / 2000.0);

*count = 0;

return result;

}

void EXTI1_IRQHandler(void)

{

if (EXTI_GetITStatus(EXTI_Line1) != RESET) 

{ 

EXTI_ClearITPendingBit(EXTI_Line1);

if (Echo == 1)

{

TIM_Cmd(TIM3, ENABLE);  

LED = 0;

}

if (Echo == 0)

{

TIM_Cmd(TIM3, DISABLE);  

LED = 1;

}

}

}