如何使用STM32F103定时器捕获四个通道输入？

目的

使用TIM5定时器的四个通道CH1-PA0，CH2-PA1，CH3-PA2，CH4-PA3来捕获输入信号；通过TIM5_CHx上的边沿信号，在边沿信号发生跳变的时候(上升沿/下降沿)时，将当前定时器的值(TIM5_CNT)存放到对应的捕获/比较寄存器(TIM5_CCRx)里面，完成一次捕获；
捕获比较通道

下图为通道1捕获比较通道：





设定CHx通道输入

CH1-PA0
CH2-PA1
CH3-PA2
CH4-PA3
滤波器设定：定义了TI1输入的采样频率和滤波器长度；

采样频率的设定在TIMx_CR1的CKD[1:0]里面设定采样频率和定时器时钟的关系：





滤波器长度表示采样x次CH1的电平若都是设定的高/低电平，才会触发输入捕获中断，可以起到滤波器的作用，滤除脉宽低于x个周期的脉冲信号；具体设置如下：





捕获极性设定和脉冲宽度计算

即设定上升沿或下降沿触发





在边沿信号发生上升沿和下降沿时，将当前定时器的值(TIM5_CNT)存放到对应的捕获/比较寄存器(TIM5_CCRx)里面，完成一次捕获，它们之差再乘采样频率的倒数(周期)就表示高电平持续时间；
还要考虑若在本例中高电平持续时间很长，以至超过自动装载寄存器ARR的值溢出，导致ARR又从0开始计数的情况；这样若还是检测下降沿的话，就会导致前面的高电平时间被忽略掉；如下图，在高电平持续期间计算器三次溢出，若检测下降沿的话就只会保留第三次后的哪一点计数；





定义如下变量;





u8 TIM5CH1_CAPTURE_STA=0; //输入捕获状态 u16 TIM5CH1_CAPTURE_VAL; //输入捕获值 捕获映射通道

可以看到IC1可以映射到TI1上也可以映射到TI2上，一般就IC1映射到TI1上就行





映射关系：





捕获分频器：选择每x个时间触发一次捕获；

例：若设定为上升沿触发，设置2个事件触发一次捕获，即为检测到两个上升沿后将当前定时器的值(TIM5_CNT)存放到对应的捕获/比较寄存器(TIM5_CCRx)里面；





触发中断：检测到上升沿/下降沿就触发中断；


代码
timer.c


#include "timer.h"
#include "led.h"
#include "usart.h"


/*输入捕获的配置步骤：
*1.初始化定时器和通道对应IO的时钟
*2.初始化IO口，模式为输入
*3.初始化定时器ARR，PSC
*4.初始化输入捕获通道
*5.如果要开启捕获中断
*6.使能定时器
*7.编写中断服务函数
*/
//定时器5通道1输入捕获配置
//初始化定时器5的结构体
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时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIOA时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0 清除之前设置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA0 输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
//GPIO_ResetBits(GPIOA,GPIO_Pin_0); //PA0 下拉

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; //PA1 清除之前设置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA1 输入
GPIO_Init(GPIOA, &GPIO_InitStructure);



GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //PA2 清除之前设置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA2 输入
GPIO_Init(GPIOA, &GPIO_InitStructure);



GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//GPIO_ResetBits(GPIOA,GPIO_Pin_3);

//初始化定时器5 TIM5
TIM_TimeBaseStructure.TIM_Period = arr; //设定计数器自动重装值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //预分频器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

//初始化TIM5输入捕获参数
TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01CC1通道被配置为输入，IC1映射到TI1上
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上,若映射到TI2上为TIM_ICSelection_IndirectTI
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频，每个边沿都触发一次捕获
TIM5_ICInitStructure.TIM_ICFilter = 0x00; //IC1F=0000 配置输入滤波器 不滤波
TIM_ICInit(TIM5, &TIM5_ICInitStructure);

TIM5_ICInitStructure.TIM_Channel = TIM_Channel_2; //CC1S=01 选择输入端 IC2映射到TI2上
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI2上
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
TIM5_ICInitStructure.TIM_ICFilter = 0x00; //IC2F=0000 配置输入滤波器，不滤波
TIM_ICInit(TIM5, &TIM5_ICInitStructure);

TIM5_ICInitStructure.TIM_Channel = TIM_Channel_3;
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM5_ICInitStructure.TIM_ICFilter = 0x00;
TIM_ICInit(TIM5, &TIM5_ICInitStructure);

TIM5_ICInitStructure.TIM_Channel = TIM_Channel_4;
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM5_ICInitStructure.TIM_ICFilter = 0x00;
TIM_ICInit(TIM5, &TIM5_ICInitStructure);

//中断分组初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占优先级2级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //从优先级0级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器

TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1|TIM_IT_CC2|TIM_IT_CC3|TIM_IT_CC4 ,ENABLE);//允许更新中（计数器溢出计数中断）,允许CC1IE捕获中断

TIM_Cmd(TIM5,ENABLE ); //使能定时器5





}


u8 TIM5CH1_CAPTURE_STA=0; //输入捕获状态
u16 TIM5CH1_CAPTURE_VAL; //输入捕获值
u8 TIM5CH2_CAPTURE_STA=0; //输入捕获状态
u16 TIM5CH2_CAPTURE_VAL; //输入捕获值
u8 TIM5CH3_CAPTURE_STA=0; //输入捕获状态
u16 TIM5CH3_CAPTURE_VAL; //输入捕获值
u8 TIM5CH4_CAPTURE_STA=0; //输入捕获状态
u16 TIM5CH4_CAPTURE_VAL; //输入捕获值


/*
--------------------------------------------------------------
bit7 | bit6 | bit5-0
------------|----------------|--------------------------------
捕获完成标志|捕获到高电平标志|捕获到高电平后定时器溢出的次数
--------------------------------------------------------------
*/
//定时器5中断服务程序
void TIM5_IRQHandler(void)
{
//CH1
//溢出中断处理部分
if((TIM5CH1_CAPTURE_STA&0X80)==0) //若bit7为0还未成功捕获
{
if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET) //检测是否发生中断

{ //若发生中断
if(TIM5CH1_CAPTURE_STA&0X40) //若bit6为1已经捕获到高电平
{
if((TIM5CH1_CAPTURE_STA&0X3F)==0X3F) //若高电平太长溢出
{
TIM5CH1_CAPTURE_STA|=0X80; //bit7赋值为1标记成功捕获了一次
TIM5CH1_CAPTURE_VAL=0XFFFF;
}else TIM5CH1_CAPTURE_STA++;
}
}
//捕获中断处理
if (TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET) //捕获1发生捕获事件
{
if(TIM5CH1_CAPTURE_STA&0X40) //若bit6为0表示上一次捕获到上升沿这次捕获到一个下降沿
{
TIM5CH1_CAPTURE_STA|=0X80; //标记成功捕获到一次上升沿
TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5);
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 设置为上升沿捕获
}else //还未开始,第一次捕获上升沿
{
TIM5CH1_CAPTURE_STA=0; //清空
TIM5CH1_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH1_CAPTURE_STA|=0X40; //标记捕获到了上升沿
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling); //设置为下降沿捕获
}
}
}

TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //清除中断标志位


//CH2
if((TIM5CH2_CAPTURE_STA&0X80)==0)
{
if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)

{
if(TIM5CH2_CAPTURE_STA&0X40)
{
if((TIM5CH2_CAPTURE_STA&0X3F)==0X3F)
{
TIM5CH2_CAPTURE_STA|=0X80;
TIM5CH2_CAPTURE_VAL=0XFFFF;
}else TIM5CH2_CAPTURE_STA++;
}
}
if (TIM_GetITStatus(TIM5, TIM_IT_CC2) != RESET)
{
if(TIM5CH2_CAPTURE_STA&0X40)
{
TIM5CH2_CAPTURE_STA|=0X80;
TIM5CH2_CAPTURE_VAL=TIM_GetCapture2(TIM5);
TIM_OC2PolarityConfig(TIM5,TIM_ICPolarity_Rising);
}else
{
TIM5CH2_CAPTURE_STA=0;
TIM5CH2_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH2_CAPTURE_STA|=0X40;
TIM_OC2PolarityConfig(TIM5,TIM_ICPolarity_Falling);
}
}
}
TIM_ClearITPendingBit(TIM5, TIM_IT_CC2|TIM_IT_Update);

//CH3
if((TIM5CH3_CAPTURE_STA&0X80)==0)
{
if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)

{
if(TIM5CH3_CAPTURE_STA&0X40)
{
if((TIM5CH3_CAPTURE_STA&0X3F)==0X3F)
{
TIM5CH3_CAPTURE_STA|=0X80;
TIM5CH3_CAPTURE_VAL=0XFFFF;
}else TIM5CH3_CAPTURE_STA++;
}
}
if (TIM_GetITStatus(TIM5, TIM_IT_CC3) != RESET)
{
if(TIM5CH3_CAPTURE_STA&0X40)
{
TIM5CH3_CAPTURE_STA|=0X80;
TIM5CH3_CAPTURE_VAL=TIM_GetCapture3(TIM5);
TIM_OC3PolarityConfig(TIM5,TIM_ICPolarity_Rising);
}else
{
TIM5CH3_CAPTURE_STA=0;
TIM5CH3_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH3_CAPTURE_STA|=0X40;
TIM_OC3PolarityConfig(TIM5,TIM_ICPolarity_Falling);
}
}
}

TIM_ClearITPendingBit(TIM5, TIM_IT_CC3|TIM_IT_Update);

//CH4
if((TIM5CH4_CAPTURE_STA&0X80)==0)
{
if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)

{
if(TIM5CH4_CAPTURE_STA&0X40)
{
if((TIM5CH4_CAPTURE_STA&0X3F)==0X3F)
{
TIM5CH4_CAPTURE_STA|=0X80;
TIM5CH4_CAPTURE_VAL=0XFFFF;
}else TIM5CH4_CAPTURE_STA++;
}
}
if (TIM_GetITStatus(TIM5, TIM_IT_CC4) != RESET)
{
if(TIM5CH4_CAPTURE_STA&0X40)
{
TIM5CH4_CAPTURE_STA|=0X80;
TIM5CH4_CAPTURE_VAL=TIM_GetCapture4(TIM5);
TIM_OC4PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 设置为上升沿捕获
}else
{
TIM5CH4_CAPTURE_STA=0;
TIM5CH4_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH4_CAPTURE_STA|=0X40;
TIM_OC4PolarityConfig(TIM5,TIM_ICPolarity_Falling);
}
}
}

TIM_ClearITPendingBit(TIM5, TIM_IT_CC4|TIM_IT_Update);
}


timer.h


#ifndef __TIMER_H
#define __TIMER_H
#include "sys.h"


void TIM5_Cap_Init(u16 arr,u16 psc);
#endif


main.c


#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "timer.h"


/*捕获TIM5四个通道：
*CH1-PA0
*CH2-PA1
*CH3-PA2
*CH4-PA3
*/
extern u8 TIM5CH1_CAPTURE_STA; //输入1捕获状态
extern u16 TIM5CH1_CAPTURE_VAL; //输入1捕获值
extern u8 TIM5CH2_CAPTURE_STA; //输入2捕获状态
extern u16 TIM5CH2_CAPTURE_VAL; //输入2捕获值
extern u8 TIM5CH3_CAPTURE_STA; //输入3捕获状态
extern u16 TIM5CH3_CAPTURE_VAL; //输入3捕获值
extern u8 TIM5CH4_CAPTURE_STA; //输入4捕获状态
extern u16 TIM5CH4_CAPTURE_VAL; //输入4捕获值
int main(void)
{
u32 temp=0;
u32 temp1=0;
u32 temp2=0;
u32 temp3=0;
delay_init();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
uart_init(115200);
LED_Init();

TIM5_Cap_Init(0XFFFF,72-1); //装载值设置为OXFFFF才会溢出以1Mhz的频率计数
while(1)
{
delay_ms(10);
if(TIM5CH1_CAPTURE_STA&0X80) //成功捕获到了一次上升沿
{
temp=TIM5CH1_CAPTURE_STA&0X3F;
temp*=65536; //溢出次数乘周期的时间
temp+=TIM5CH1_CAPTURE_VAL; //再加上当前状态值得到总的高电平时间
printf("CH1:%d usrn",temp); //打印总的高点平时间
TIM5CH1_CAPTURE_STA=0; //开启下一次捕获
}
if(TIM5CH2_CAPTURE_STA&0X80)
{
temp1=TIM5CH2_CAPTURE_STA&0X3F;
temp1*=65536;
temp1+=TIM5CH2_CAPTURE_VAL;
//printf("CH2:%d usrn",temp1);vb
TIM5CH2_CAPTURE_STA=0;
}
if(TIM5CH3_CAPTURE_STA&0X80)
{
temp2=TIM5CH3_CAPTURE_STA&0X3F;
temp2*=65536;
temp2+=TIM5CH3_CAPTURE_VAL;
//printf("CH3:%d usrn",temp2);
TIM5CH3_CAPTURE_STA=0;
}
if(TIM5CH4_CAPTURE_STA&0X80)
{
temp3=TIM5CH4_CAPTURE_STA&0X3F;
temp3*=65536;
temp3+=TIM5CH4_CAPTURE_VAL;
//printf("CH4:%d usrn",temp3);
TIM5CH4_CAPTURE_STA=0;
}
}
}