基于STM32f103的超聲波測距（串口1顯示）程序問題

ID:692948 · 發(fā)表于 2020-10-10 12:54

還有一點(diǎn)問題就是最大測17cm,后面就顯示不出，希望大神們指導(dǎo)下，我是個小白

#include "timer.h"
#include "led.h"
#include "usart.h"
#include "delay.h"
//通用定時(shí)器中斷初始化
//這里時(shí)鐘選擇為APB1的2倍，而APB1為36M
//arr：自動重裝值。
//psc：時(shí)鐘預(yù)分頻數(shù)
//定時(shí)器5通道1輸入捕獲配置
TIM_ICInitTypeDef TIM5_ICInitStructure;
void TIM5_Cap_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE); //使能TIM5時(shí)鐘
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIOA時(shí)鐘
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0 清除之前設(shè)置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA0 輸入
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_ResetBits(GPIOA,GPIO_Pin_0); //PA0 下拉
//初始化定時(shí)器5 TIM5
TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)定計(jì)數(shù)器自動重裝值
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:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計(jì)數(shù)模式
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時(shí)間基數(shù)單位
//初始化TIM5輸入捕獲參數(shù)
TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01 選擇輸入端 IC1映射到TI1上
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕獲
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置輸入分頻,不分頻
TIM5_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置輸入濾波器不濾波
TIM_ICInit(TIM5, &TIM5_ICInitStructure);
//中斷分組初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; //TIM5中斷
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占優(yōu)先級2級
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //從優(yōu)先級0級
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器
TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);//允許更新中斷 ,允許CC1IE捕獲中斷
TIM_Cmd(TIM5,ENABLE ); //使能定時(shí)器5
}
u8 TIM5CH1_CAPTURE_STA=0; //輸入捕獲狀態(tài)
u16 TIM5CH1_CAPTURE_VAL; //輸入捕獲值
//定時(shí)器5中斷服務(wù)程序
void TIM5_IRQHandler(void)
{
if(TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET)
{
if(TIM5CH1_CAPTURE_STA==1)
{
TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5);
printf("探測距離為：%.2f cm\r\n",TIM5CH1_CAPTURE_VAL*17/1000.0);
TIM5CH1_CAPTURE_STA=0;
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 設(shè)置為上升沿捕獲
}
else
{
TIM5CH1_CAPTURE_VAL = 0;
TIM5CH1_CAPTURE_STA =1;
TIM_SetCounter(TIM5,0);
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling); //CC1P=1 設(shè)置為下降沿捕獲
TIM_Cmd(TIM5,ENABLE);
}
}
TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //清除中斷標(biāo)志位
}

復(fù)制代碼

帳號		自動登錄	找回密碼
密碼			立即注冊

亚洲春色中文字幕久久久-三上亚,一吻二脱三床四吻胸,国产真实伦对白视频全集,在线毛片观看,精品成品入口黄网,国产毛aⅴ片久久久,亚洲AV色香蕉一区二区三区老师,萧皇后A级艳片,色情日本视频更新,99久久亚洲精品日本无码

基于STM32f103的超聲波測距（串口1顯示）程序問題