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hs04.c
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#include "hsr04.h"
#include <string.h>
#include <stdio.h>
#include "delay.h"
#define Trig PBout(0) // PB0
#define Echo PBin(1) // PB1
void HCSR04_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);//使能TIM2時(shí)鐘
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOA,ENABLE);//使能GPIOA/GPIOB時(shí)鐘
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉輸入
GPIO_Init(GPIOB,&GPIO_InitStructure);
GPIO_ResetBits(GPIOB,GPIO_Pin_1);//PB1 下拉
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOB,&GPIO_InitStructure);//PB0 推挽輸出
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_5 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉輸入
GPIO_Init(GPIOA,&GPIO_InitStructure);
GPIO_ResetBits(GPIOA,GPIO_Pin_1);//PB1 下拉
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_4 | GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);//PB0 推挽輸出
//初始化定時(shí)器 2 TIM2
TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)定計(jì)數(shù)器自動(dòng)重裝值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //預(yù)分頻器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設(shè)置時(shí)鐘分割
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上計(jì)數(shù)
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //初始化 TIM2
}
//一號(hào)超聲波 前方
float hsr04_get(void)
{
int rate_time =0;
uint16_t cnt=0;
float dis=0;
//發(fā)出起始信號(hào)
Trig=0;
DelayUs(10);
Trig=1;
DelayUs(15); //輸入一個(gè)10us的高電平
Trig=0;
while(Echo == 0); //超聲波發(fā)射出去
TIM_Cmd(TIM2 ,ENABLE); //開啟定時(shí)器
while(Echo == 1) //超聲波反射回來,來回時(shí)間不超過20ms，單程距離不超過3.4m
{
DelayUs(20);
rate_time ++;
if(rate_time>=1000)
break;
}
TIM_Cmd(TIM2 ,DISABLE); //關(guān)閉定時(shí)器
cnt = TIM_GetCounter(TIM2); //獲取定時(shí)器的計(jì)數(shù)值
dis = ((float)cnt) / 58 ; //單位：cm
TIM2->CNT = 0;
return dis;
}
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