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用的芯片是stm32f103c8t6
#include "encoder.h"
#include "usart.h"
#include "delay.h"
uint8_t TIM3CH3_CAPTURE_STA=0; //輸入捕獲狀態(tài)
uint16_t TIM3CH3_CAPTURE_VAL; //輸入捕獲值
int distance = 0;
void Encoder_Init_TIM3(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_ICInitTypeDef TIM3_ICInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);//使能定時器3的時鐘
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);//使能PA端口時鐘
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //端口配置 PA6 PA7
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //浮空輸入
GPIO_Init(GPIOB, &GPIO_InitStructure); //根據(jù)設(shè)定參數(shù)初始化GPIOA
GPIO_ResetBits(GPIOB,GPIO_Pin_0); //PB8 下拉
//初始化定時器4 TIM3
TIM_TimeBaseStructure.TIM_Period = 0XFFFF; //設(shè)定計(jì)數(shù)器自動重裝值
TIM_TimeBaseStructure.TIM_Prescaler =72-1; //預(yù)分頻器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設(shè)置時鐘分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計(jì)數(shù)模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位
//初始化TIM2輸入捕獲參數(shù)
TIM3_ICInitStructure.TIM_Channel = TIM_Channel_3;
TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕獲
TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置輸入分頻,不分頻
TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置輸入濾波器 不濾波
TIM_ICInit(TIM3, &TIM3_ICInitStructure);
//中斷分組初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中斷
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //先占優(yōu)先級2級
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //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(TIM3,TIM_IT_Update|TIM_IT_CC3,ENABLE);//允許更新中斷 ,允許CC1IE捕獲中斷
TIM_Cmd(TIM3,ENABLE ); //使能定時器4
}
void TIM3_IRQHandler(void)
{
if((TIM3CH3_CAPTURE_STA&0X80)==0)//還未成功捕獲
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
if(TIM3CH3_CAPTURE_STA&0X40)//已經(jīng)捕獲到高電平了
{
if((TIM3CH3_CAPTURE_STA&0X3F)==0X3F)//高電平太長了
{
TIM3CH3_CAPTURE_STA|=0X80;//標(biāo)記成功捕獲了一次
TIM3CH3_CAPTURE_VAL=0XFFFF;
}else TIM3CH3_CAPTURE_STA++;
}
}
if (TIM_GetITStatus(TIM3, TIM_IT_CC3) != RESET)//捕獲1發(fā)生捕獲事件
{
if(TIM3CH3_CAPTURE_STA&0X40) //捕獲到一個下降沿
{
TIM3CH3_CAPTURE_STA|=0X80; //標(biāo)記成功捕獲到一次上升沿
TIM3CH3_CAPTURE_VAL=TIM_GetCapture3(TIM3);
TIM_OC3PolarityConfig(TIM3,TIM_ICPolarity_Rising); //CC1P=0 設(shè)置為上升沿捕獲
}else //還未開始,第一次捕獲上升沿
{
TIM3CH3_CAPTURE_STA=0; //清空
TIM3CH3_CAPTURE_VAL=0;
TIM_SetCounter(TIM3,0);
TIM3CH3_CAPTURE_STA|=0X40; //標(biāo)記捕獲到了上升沿
TIM_OC3PolarityConfig(TIM3,TIM_ICPolarity_Falling); //CC1P=1 設(shè)置為下降沿捕獲
}
}
}
TIM_ClearITPendingBit(TIM3, TIM_IT_CC3|TIM_IT_Update); //清除中斷標(biāo)志位
}
void Count_Dist(void)
{
delay_init(); //在 delay.h 中
TRIG_Init();
GPIO_SetBits(GPIOB, GPIO_Pin_12);
delay_us(15);
GPIO_ResetBits(GPIOB, GPIO_Pin_12);
if(TIM3CH3_CAPTURE_STA&0X80)//成功捕獲到了一次高電平
{
distance=TIM3CH3_CAPTURE_STA&0X3F;
distance*=65536; //溢出時間總和
distance+=TIM3CH3_CAPTURE_VAL; //得到總的高電平時間
distance=distance*170*0.0001;
printf("distance:%d cm\r\n",distance); //打印總的高點(diǎn)平時間
TIM3CH3_CAPTURE_STA=0; //開啟下一次捕獲
}
}
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