注意：定义GPIOB2为超声输出；GPIOB10为输入，定时器用tim2
///.CPP文件/
#include "HCSR04.h"
#include "delay.h" #include "sys.h" int overcount; float length=0; void HCSR04_init() { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructer; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB , ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(GPIOB, &GPIO_InitStructure); TIM_DeInit(TIM2); TIM_TimeBaseInitStructer.TIM_Period=4999; TIM_TimeBaseInitStructer.TIM_Prescaler=7199; TIM_TimeBaseInitStructer.TIM_ClockDivision=TIM_CKD_DIV1; TIM_TimeBaseInitStructer.TIM_CounterMode=TIM_CounterMode_Up; TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructer); TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); TIM_ITConfig( TIM2, TIM_IT_Update | TIM_IT_Trigger, ENABLE ); TIM_ClearFlag(TIM2,TIM_FLAG_Update) ; NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); TIM_Cmd(TIM2,DISABLE); } float HCSR04_Read() { float sum=0,length1=0; u8 i=0,j=0; u16 tim; { // while(i!=5) for(i=0;i<5;i++) { PBout(2)=1; delay_us(20); PBout(2)=0; while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_10)==RESET); TIM_SetCounter(TIM2,0); TIM_Cmd(TIM2,ENABLE); while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_10)==SET); TIM_Cmd(TIM2,DISABLE); tim=TIM2->CNT; length1=tim/58.0*100; TIM2->CNT=0; sum+=length1; } } length=sum/5; sum=0; return length;}
///.h文件//
#include "stm32f10x_lib.h" #define PBout(n) BIT_ADDR(GPIOB_ODR_Addr,n) //Êä³ö #define PBin(n) BIT_ADDR(GPIOB_IDR_Addr,n) //ÊäÈë extern float HCSR04_Read(); extern void HCSR04_init(); //extern void HC_RS04_Init();
