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//测五次数据之后计算平均值,将平均值与10对比,若小于10则点亮LED,否则不亮。
#include "cs.h"
#include "stm32f10x.h"
#define D1_ON GPIO_ResetBits(GPIOC,GPIO_Pin_13)
#define D1_OFF GPIO_SetBits(GPIOC,GPIO_Pin_13)
float length;
uint overcount=0;
void LED_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOC, ENABLE);
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_13;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_Init(GPIOC,&GPIO_InitStructure);
}
void delay_us(u16 time)
{
u16 i=0;
while(time--)
{
i=12000;
while(i--);
}
}
void NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructer;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructer.NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructer.NVIC_IRQChannelSubPriority=0;
NVIC_InitStructer.NVIC_IRQChannel=TIM2_IRQn;
NVIC_InitStructer.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructer);
}
void CH_SR04_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructer;
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructer;
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
GPIO_InitStructer.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructer.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_InitStructer.GPIO_Pin=GPIO_Pin_8;
GPIO_Init(GPIOB, &GPIO_InitStructer);
GPIO_InitStructer.GPIO_Mode=GPIO_Mode_IN_FLOATING;
GPIO_InitStructer.GPIO_Pin=GPIO_Pin_9;
GPIO_Init(GPIOB, & GPIO_InitStructer);
TIM_DeInit(TIM2);
TIM_TimeBaseInitStructer.TIM_Period=999;
TIM_TimeBaseInitStructer.TIM_Prescaler=71;
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);
NVIC_Config();
TIM_Cmd(TIM2,DISABLE);
}
float Senor_Using(void)
{
float length=0,sum=0;
u16 tim;
uint i=0;
while(i!=5)
{
GPIO_SetBits(GPIOB,GPIO_Pin_8);
delay_us(20);
GPIO_ResetBits(GPIOB,GPIO_Pin_8);
while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_9)==RESET);
TIM_Cmd(TIM2,ENABLE);
i+=1;
while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_9)==SET);
TIM_Cmd(TIM2,DISABLE);
tim=TIM_GetCounter(TIM2);
length=(tim+overcount*1000)/58.0;
sum=length+sum;
TIM2->CNT=0;
overcount=0;
delay_us(600);
}
length=sum/5;
return length;
}
void TIM2_IRQHandler(void)
{
if(TIM_GetITStatus(TIM2,TIM_IT_Update)!=RESET)
{
TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
overcount++;
}
}
int main(void)
{
void CH_SR04_Init(void);
void NVIC_Config(void);
void delay_nms(u16 time);
float Senor_Using(void);
LED_GPIO_Config();
if( length<=10)
{
D1_ON;
delay_us(200);
}
else
{
D1_OFF;
delay_us(200);
}
}
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