目录
一、输入捕获简介
二、频率测量方法
三、输入捕获框图
四、输入捕获通道
五、输入捕获基本结构
六、PWMI基本结构
七、开发步骤
八、输入捕获库函数
九、实验
9.1 输入捕获测频率
9.2 PWMI模式测频率和占空比
一、输入捕获简介
>IC(Input Capture)输入捕获
>输入捕获模式下,当通道输入引脚出现指定电平跳变时,当前CNT的值将被锁存到CCR 中,可用于测量PWM波形的频率、占空比、脉冲间隔、电平持续时间等参数
>每个高级定时器和通用定时器都拥有4个输入捕获通道
>可配置为PWMI模式,同时测量频率和占空比
>可配合主从触发模式,实现硬件全自动测量
二、频率测量方法
三、输入捕获框图
四、输入捕获通道
五、输入捕获基本结构
六、PWMI基本结构
七、开发步骤
①RCC开启时钟,GPIO和TIM时钟打开
②GPIO初始化,把GPIO配置成输入模式
③配置时基单元,让CNT计数器在内部时钟的驱动下自增运行
④配置输入捕获单元(滤波器,极性,直连/交叉通道,分频器)
⑤选择从模式的触发源
⑥选择触发后执行的操作
⑦调用TIM_Cmd函数,开启定时器
八、输入捕获库函数
void TIM_ICInit(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct);
//结构体配置输入捕获单元(单个通道)
void TIM_PWMIConfig(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct);
//配置两个通道
void TIM_SelectInputTrigger(TIM_TypeDef* TIMx, uint16_t TIM_InputTriggerSource);
//选择输入触发源TRGI
void TIM_SelectOutputTrigger(TIM_TypeDef* TIMx, uint16_t TIM_TRGOSource);
//选择输出触发源TRGO
void TIM_SelectSlaveMode(TIM_TypeDef* TIMx, uint16_t TIM_SlaveMode);
//选择从模式
======================配置各个通道的预分频器============================
void TIM_SetIC1Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC2Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC3Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC4Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);======================分别读取4个通道的CCR=============================
uint16_t TIM_GetCapture1(TIM_TypeDef* TIMx);
uint16_t TIM_GetCapture2(TIM_TypeDef* TIMx);
uint16_t TIM_GetCapture3(TIM_TypeDef* TIMx);
uint16_t TIM_GetCapture4(TIM_TypeDef* TIMx);
九、实验
9.1 输入捕获测频率
实验设置:PA0输出PWM波,PA6输入捕获
PWM.c
#include "stm32f10x.h" // Device header/*PWM初始化*/ void PWM_Init(void) {/*一、RCC开启时钟,TIM与GPIO时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);// /*使用重映射(*_*)*/ // RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); // GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2,ENABLE);//PA0->PA15 // GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE);//解除JATG调试GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//(*_*)GPIO_Pin_15GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*二、配置时基单元(时钟源选择和时基单元配置)*/TIM_InternalClockConfig(TIM2);//选择内部时钟TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;TIM_TimeBaseInitStructure.TIM_Period = 100 - 1; //ARR自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);/*三、配置输出比较单元(CCR的值(捕获/比较器),输出比较模式,极性选择,输出使能)*/TIM_OCInitTypeDef TIM_OCInitStructure;TIM_OCStructInit(&TIM_OCInitStructure);//给结构体所有成员赋初始值(有些用不到但是必须赋值)TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//输出比较模式TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较的极性TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出使能TIM_OCInitStructure.TIM_Pulse = 0;//设置CCRTIM_OC1Init(TIM2,&TIM_OCInitStructure);/*四、配置GPIO,复用推挽输出*///一处已操作/*五、运行控制,启动计数器CNT*/TIM_Cmd(TIM2,ENABLE); }/*封装函数->更改CCR值来改变占空比*/ void PWM_SetCompare1(uint16_t Compare) {TIM_SetCompare1(TIM2,Compare); }/*通过PSC的改变来修改频率*/ void PWM_SetPrescaler(uint16_t Prescaler) {TIM_PrescalerConfig(TIM2,Prescaler,TIM_PSCReloadMode_Immediate); }
PWM.h
#ifndef __PWM_H #define __PWM_Hvoid PWM_Init(void); void PWM_SetCompare1(uint16_t Compare); void PWM_SetPrescaler(uint16_t Prescaler);#endif
IC.c
#include "stm32f10x.h" // Device header//输入捕获初始化 void IC_Init(void) {/*一、RCC开启时钟,GPIO和TIM时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);/*二、GPIO初始化,把GPIO配置成输入模式*/GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*三、配置时基单元,让CNT计数器在内部时钟的驱动下自增运行*/TIM_InternalClockConfig(TIM3);//选择内部时钟TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;TIM_TimeBaseInitStructure.TIM_Period = 65536 - 1; //ARR自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);/*四、配置输入捕获单元(滤波器,极性,直连/交叉通道,分频器)*/TIM_ICInitTypeDef TIM_ICInitStructure;TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;//通道TIM_ICInitStructure.TIM_ICFilter = 0xF;//滤波器TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;//上升沿触发 TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;//不分频TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//直连通道TIM_ICInit(TIM3,&TIM_ICInitStructure);/*五、选择从模式的触发源(TI1FP1)*/TIM_SelectInputTrigger(TIM3,TIM_TS_TI1FP1);/*六、选择触发后执行的操作,Reset重置CNT*/TIM_SelectSlaveMode(TIM3,TIM_SlaveMode_Reset);/*七、调用TIM_Cmd函数,开启定时器*/TIM_Cmd(TIM3,ENABLE); }uint32_t IC_GetFreq(void) {return 1000000 / (TIM_GetCapture1(TIM3) + 1); }
IC.h
#ifndef __IC_H #define __IC_Hvoid IC_Init(void); uint32_t IC_GetFreq(void);#endif
main.c
#include "stm32f10x.h" // Device header #include "Delay.h" #include "OLED.h" #include "PWM.h" #include "IC.h"int main(void) {OLED_Init();PWM_Init();IC_Init();//(输出比较)输出一个频率1kHz,占空比50%的PWM信号 PWM_SetPrescaler(720-1); //频率f = 72M / (PSC+1)(ARR+1)PWM_SetCompare1(50); //Duty = CCR/(ARR+1)//输入捕获//IC_GetFreq();OLED_ShowString(1,1,"Freq:");OLED_ShowString(1,11,"Hz");while (1){OLED_ShowNum(1,6,IC_GetFreq(),5);} }
9.2 PWMI模式测频率和占空比
PWM.c
#include "stm32f10x.h" // Device header/*PWM初始化*/ void PWM_Init(void) {/*一、RCC开启时钟,TIM与GPIO时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);// /*使用重映射(*_*)*/ // RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); // GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2,ENABLE);//PA0->PA15 // GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE);//解除JATG调试GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//(*_*)GPIO_Pin_15GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*二、配置时基单元(时钟源选择和时基单元配置)*/TIM_InternalClockConfig(TIM2);//选择内部时钟TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;TIM_TimeBaseInitStructure.TIM_Period = 100 - 1; //ARR自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);/*三、配置输出比较单元(CCR的值(捕获/比较器),输出比较模式,极性选择,输出使能)*/TIM_OCInitTypeDef TIM_OCInitStructure;TIM_OCStructInit(&TIM_OCInitStructure);//给结构体所有成员赋初始值(有些用不到但是必须赋值)TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//输出比较模式TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较的极性TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出使能TIM_OCInitStructure.TIM_Pulse = 0;//设置CCRTIM_OC1Init(TIM2,&TIM_OCInitStructure);/*四、配置GPIO,复用推挽输出*///一处已操作/*五、运行控制,启动计数器CNT*/TIM_Cmd(TIM2,ENABLE); }/*封装函数->更改CCR值来改变占空比*/ void PWM_SetCompare1(uint16_t Compare) {TIM_SetCompare1(TIM2,Compare); }/*通过PSC的改变来修改频率*/ void PWM_SetPrescaler(uint16_t Prescaler) {TIM_PrescalerConfig(TIM2,Prescaler,TIM_PSCReloadMode_Immediate); }
PWM.h
#ifndef __PWM_H #define __PWM_Hvoid PWM_Init(void); void PWM_SetCompare1(uint16_t Compare); void PWM_SetPrescaler(uint16_t Prescaler);#endif
IC.c
#include "stm32f10x.h" // Device header//输入捕获初始化 void IC_Init(void) {/*一、RCC开启时钟,GPIO和TIM时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);/*二、GPIO初始化,把GPIO配置成输入模式*/GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*三、配置时基单元,让CNT计数器在内部时钟的驱动下自增运行*/TIM_InternalClockConfig(TIM3);//选择内部时钟TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;TIM_TimeBaseInitStructure.TIM_Period = 65536 - 1; //ARR自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);/*四、配置输入捕获单元(滤波器,极性,直连/交叉通道,分频器)*/TIM_ICInitTypeDef TIM_ICInitStructure;TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;TIM_ICInitStructure.TIM_ICFilter = 0xF;//滤波器TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;//不分频TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//直连通道TIM_PWMIConfig(TIM3,&TIM_ICInitStructure);//通道2,交叉,下降沿检测/*五、选择从模式的触发源(TI1FP1)*/TIM_SelectInputTrigger(TIM3,TIM_TS_TI1FP1);/*六、选择触发后执行的操作,Reset重置CNT*/TIM_SelectSlaveMode(TIM3,TIM_SlaveMode_Reset);/*七、调用TIM_Cmd函数,开启定时器*/TIM_Cmd(TIM3,ENABLE); }/*频率*/ uint32_t IC_GetFreq(void) {return 1000000 / (TIM_GetCapture1(TIM3) + 1); }/*占空比*/ uint32_t IC_GetDuty(void) {return (TIM_GetCapture2(TIM3)+1) * 100 / (TIM_GetCapture1(TIM3)+1); }
IC.h
#ifndef __IC_H #define __IC_Hvoid IC_Init(void); uint32_t IC_GetFreq(void); uint32_t IC_GetDuty(void);#endif
main.c
#include "stm32f10x.h" // Device header #include "Delay.h" #include "OLED.h" #include "PWM.h" #include "IC.h"int main(void) {OLED_Init();PWM_Init();IC_Init();OLED_ShowString(1,1,"Freq:00000Hz");OLED_ShowString(2,1,"Duty:00%");//(输出比较)输出一个频率1kHz,占空比50%的PWM信号 PWM_SetPrescaler(720-1); //f = 72M / (PSC+1)(ARR+1)PWM_SetCompare1(50); //Duty = CCR/(ARR+1)//输入捕获//IC_GetFreq();//IC_GetDuty();while (1){OLED_ShowNum(1,6,IC_GetFreq(),5);OLED_ShowNum(2,6,IC_GetDuty(),2);} }