STM32 study notes (12)

STM32F103ZET6 timer interrupt experiment

---

---

Preface

The learning of STM32 can be divided into 3 versions.
1. Register version
2. Library function version
3. HAL library version
Due to personal reasons, I choose the library function version to learn STM32.

---

Tip: Problems such as software installation will not be explained! ! !

1. The basic principle of timer

1. Resource introduction

2. General timer function

3. Introduction to counting mode

4. Working principle

2. Related registers

1. Control register 1 (TIMx_CR1)

2. DMA/interrupt enable register (TIMx_DIER)

3. Prescaler register (TIMx_PSC)

4. Auto reload register (TIMx_ARR)

5. Counter current value register (TIMx_CNT)

Three, operation steps

1. Overflow time calculation

2. Operation steps

Fourth, the program source code

1.timer.h

code show as below:

#ifndef __TIMER_H
#define __TIMER_H

#include "sys.h"

void TIM3_Int_Init(u16 arr,u16 psc);

#endif

2.timer.c

code show as below:

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

void TIM3_Int_Init(u16 arr,u16 psc)
{
    
    
	TIM_TimeBaseInitTypeDef IM_TimeBaseInitstr;
	NVIC_InitTypeDef NVIC_Initstr;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);//定时器时钟使能
	
	IM_TimeBaseInitstr.TIM_Period=arr;
	IM_TimeBaseInitstr.TIM_Prescaler=psc;
	IM_TimeBaseInitstr.TIM_CounterMode=TIM_CounterMode_Up;
	IM_TimeBaseInitstr.TIM_ClockDivision=TIM_CKD_DIV1;
	TIM_TimeBaseInit(TIM3, &IM_TimeBaseInitstr);//初始化时钟
	
	TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);//开启定时器中断
	
	NVIC_Initstr.NVIC_IRQChannel=TIM3_IRQn;
	NVIC_Initstr.NVIC_IRQChannelCmd=ENABLE;
	NVIC_Initstr.NVIC_IRQChannelPreemptionPriority=0;
	NVIC_Initstr.NVIC_IRQChannelSubPriority=2;
	NVIC_Init(&NVIC_Initstr);//配置NVIC
	
	TIM_Cmd(TIM3, ENABLE);//使能定时器
}
void TIM3_IRQHandler(void)//中断服务函数
{
    
    
	if(TIM_GetITStatus(TIM3, TIM_IT_Update)==SET)
	{
    
    
		TIM_ClearITPendingBit(TIM3, TIM_IT_Update);//清除更新中断标志
		LED1=!LED1;
	}
}

3.main.c

code show as below:

#include "stm32f10x.h"
#include "led.h"
#include "delay.h"
#include "beep.h"
#include "key.h"
#include "timer.h"

int main(void)
{
    
    
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	delay_init();
    LED_Init();
	Beep_Init();
	KEY_Init();
	TIM3_Int_Init(4999,7199);//间隔500ms
	while(1)
	{
    
    
		LED2=!LED2;
		delay_ms(200);
	}
}

5. Experimental results

LED1 status reversal, interval 500ms; (timer)
LED2 status reversal, interval 200ms; (delay)

---

to sum up

adhere to! ! !