代码收藏家技术教程 2023-07-28

STM32输入捕获测频率方法详解

本文章转自B站江科大自化协

1，输入捕获测频率

接线图

目录结构

IC.h

#ifndef __IC_H
#define __IC_H

void IC_Init(void);
uint32_t IC_GetFreq(void);

#endif

IC.c

#include "stm32f10x.h"                  // Device header

void IC_Init(void)
{
	//1，输入捕获的初始化
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);//开启TIM3时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//开启GPIOA的时候
	
	//2.GPIO初始化  把GPIO配置输入模式
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	//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
	TIM_InternalClockConfig(TIM3);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//向上计数的模式
	TIM_TimeBaseInitStructure.TIM_Period = 65536 - 1;		//ARR
	TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1;		//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);
	//4.配置输入捕获单元包括滤波器，极性，直连通道还是交叉通道，分频器等参数
	TIM_ICInitTypeDef TIM_ICInitStructure;
	TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;//选择通道
	TIM_ICInitStructure.TIM_ICFilter = 0xF;         //配置输入捕获的滤波器
	TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;//极性 选择上升沿触发
	TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;  //分频器 1为不分频
	TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//选择触发信号从哪个引脚输入。直连通道
	TIM_ICInit(TIM3, &TIM_ICInitStructure);
	
	//5.配置TRGI的触发源为TI1FP1
	TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1);
	//6.配置从模式为Reset
	TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
	//7.启动定时器
	TIM_Cmd(TIM3, ENABLE);
}

uint32_t IC_GetFreq(void)
{
	return 1000000 / (TIM_GetCapture1(TIM3) + 1);//返回最新一个周期的频率值单位Hz
}

pwm.c

#include "stm32f10x.h"                  // Device header

void PWM_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	

	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;		//GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_InternalClockConfig(TIM2);
	
	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
	TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1;		//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);
	
	TIM_OCInitTypeDef TIM_OCInitStructure;
	TIM_OCStructInit(&TIM_OCInitStructure);
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR
	TIM_OC1Init(TIM2, &TIM_OCInitStructure);
	
	TIM_Cmd(TIM2, ENABLE);
}

//通过SetCompare1改变通道1的占空比
void PWM_SetCompare1(uint16_t Compare)
{
	TIM_SetCompare1(TIM2, Compare);
}
//通过PWM_SetPrescaler改变频率
void PWM_SetPrescaler(uint16_t Prescaler)
{
	TIM_PrescalerConfig(TIM2, Prescaler, TIM_PSCReloadMode_Immediate);//单独写入PSC的函数
}

PWM.h

#ifndef __PWM_H
#define __PWM_H

void PWM_Init(void);
void PWM_SetCompare1(uint16_t Compare);
void PWM_SetPrescaler(uint16_t Prescaler);

#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");
	
	PWM_SetPrescaler(720 - 1);			//Freq = 72M / (PSC + 1) / 100
	PWM_SetCompare1(50);				//Duty = CCR / 100
	
	while (1)
	{
		OLED_ShowNum(1, 6, IC_GetFreq(), 5);
	}
}

编译下载出结果

2.PWM模式测频率占空比

接线图同上

目录结构同上

IC.c

#include "stm32f10x.h"                  // Device header

void IC_Init(void)
{
	//1，输入捕获的初始化
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);//开启TIM3时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//开启GPIOA的时候
	
	//2.GPIO初始化  把GPIO配置输入模式
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	//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
	TIM_InternalClockConfig(TIM3);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//向上计数的模式
	TIM_TimeBaseInitStructure.TIM_Period = 65536 - 1;		//ARR
	TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1;		//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);
	//4.配置成两个通道同时捕获同一个引脚的模式
	TIM_ICInitTypeDef TIM_ICInitStructure;
	TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;//选择通道
	TIM_ICInitStructure.TIM_ICFilter = 0xF;         //配置输入捕获的滤波器
	TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;//极性 选择上升沿触发
	TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;  //分频器 1为不分频
	TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//选择触发信号从哪个引脚输入。直连通道
	TIM_ICInit(TIM3, &TIM_ICInitStructure);
	//方法一
//	TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;//选择通道
//	TIM_ICInitStructure.TIM_ICFilter = 0xF;         //配置输入捕获的滤波器
//	TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;//极性 选择下降沿触发
//	TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;  //分频器 1为不分频
//	TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_IndirectTI;//选择触发信号从哪个引脚输入。交叉通道
//	TIM_ICInit(TIM3, &TIM_ICInitStructure);
	//方法二
	TIM_PWMIConfig(TIM3,&TIM_ICInitStructure);
	//5.配置TRGI的触发源为TI1FP1
	TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1);
	//6.配置从模式为Reset
	TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
	//7.启动定时器
	TIM_Cmd(TIM3, ENABLE);
}

uint32_t IC_GetFreq(void)
{
	return 1000000 / (TIM_GetCapture1(TIM3) + 1);//返回最新一个周期的频率值单位Hz
}
//获取占空比的函数
uint32_t IC_GetDuty(void)
{
	return (TIM_GetCapture2(TIM3)+1) *100 / (TIM_GetCapture1(TIM3)+1);

}

IC.h

#ifndef __IC_H
#define __IC_H

void 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%");
	
	PWM_SetPrescaler(7200 - 1);			//Freq = 72M / (PSC + 1) / 100
	PWM_SetCompare1(80);				//Duty = CCR / 100
	
	while (1)
	{
		OLED_ShowNum(1, 6, IC_GetFreq(), 5);
		OLED_ShowNum(2, 6, IC_GetDuty(), 2);
	}
}

编译下载测试