江科大stm32学习笔记【6-2】——定时器定时中断&定时器外部时钟

一.定时器定时中断

1.原理

2.硬件

3.程序

 此时CK_PSC=72M，定时1s，也就是定时频率为1Hz，所以可以PSC=7200-1,ARR=10000-1。

Timer.c:

#include "stm32f10x.h"                  // Device header

extern uint16_t Num;//声明跨文件的变量

void Timer_Init(void)
{
	//1.RCC开启时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
	//2.选择时基单元的时钟源
	TIM_InternalClockConfig(TIM2);//内部时钟源
	//3.配置时基单元包括预分频器，自动重装器，计数模式）
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;//分频器：1分频
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//计数器：向上计数
	TIM_TimeBaseInitStructure.TIM_Period = 10000-1;//ARR自动重装器的值
	TIM_TimeBaseInitStructure.TIM_Prescaler = 7200-1;//PSC预分频器的值
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器的值(高级定时器才有，我们写0 就好)
	
	TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);
	//4.配置输出中断控制，允许更新中断输出到NVIC
	TIM_ClearFlag(TIM2,TIM_FLAG_Update);//清除更新中断标志位，避免刚初始化就进中断
	TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);//使能中断,开启更新中断到NVIC的中路
	//5.配置NVIC,在NVIC中打开定时器中断的通道
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//NVIC优先级分组
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;//定时器2在NVIC的通道
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	//6.运行控制(启动定时器)
	TIM_Cmd(TIM2,ENABLE);
	
}

void TIM2_IRQHandler(void)//中断函数
{
	//检查中断标志位：
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		Num++;
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}

 Timer.h:

#ifndef __TIMER_H
#define __TIMER_H

void Timer_Init(void);

#endif

main.c:

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Timer.h"

uint16_t Num;

int main(void)
{
	OLED_Init();
	Timer_Init();
	OLED_ShowString(1,1,"Num:");//显示字符串
	
	while(1)
	{
		OLED_ShowNum(2,1,Num,5);
		OLED_ShowNum(3,1,TIM_GetCounter(TIM2),5);//看计数器
	}
}

二.外部定时器中断

1.硬件

2.程序

Timer.c:

#include "stm32f10x.h"                  // Device header

extern uint16_t Num;//声明跨文件的变量

void Timer_Init(void)
{
	//1.RCC开启时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
	//2.配置GPIO引脚
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉输入
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitStructure);
	
	//3.选择时基单元的时钟源
	TIM_ETRClockMode2Config(TIM2,TIM_ExtTRGPSC_OFF,TIM_ExtTRGPolarity_NonInverted,0x0F);//通过ETR引脚的外部时钟模式2配置
	//TIM_ExtTRGPSC_OFF:外部触发预分频器：不需要分频
	//TIM_ExtTRGPolarity_NonInverted:外部触发的极性：不反向，高电平或上升沿有效
	//0x0F:外部触发滤波器：0x00时CNT变太快(看手册选值)
	
	//4.配置时基单元包括预分频器，自动重装器，计数模式）
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;//分频器：1分频
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//计数器：向上计数
	TIM_TimeBaseInitStructure.TIM_Period = 10-1;//ARR自动重装器的值
	TIM_TimeBaseInitStructure.TIM_Prescaler = 1-1;//PSC预分频器的值
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器的值(高级定时器才有，我们写0 就好)
	
	TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);
	//5.配置输出中断控制，允许更新中断输出到NVIC
	TIM_ClearFlag(TIM2,TIM_FLAG_Update);//清除更新中断标志位，避免刚初始化就进中断
	TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);//使能中断,开启更新中断到NVIC的中路
	//6.配置NVIC,在NVIC中打开定时器中断的通道
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//NVIC优先级分组
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;//定时器2在NVIC的通道
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	//7.运行控制(启动定时器)
	TIM_Cmd(TIM2,ENABLE);
	
}

uint16_t Timer_GetCounter(void)
{
	return TIM_GetCounter(TIM2);
}

void TIM2_IRQHandler(void)//中断函数
{
	//检查中断标志位：
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		Num++;
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}

Timer.h:

#ifndef __TIMER_H
#define __TIMER_H

void Timer_Init(void);
uint16_t Timer_GetCounter(void);

#endif

main.c:

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Timer.h"

uint16_t Num;

int main(void)
{
	OLED_Init();
	Timer_Init();
	OLED_ShowString(1,1,"Num:");//显示字符串
	OLED_ShowString(2,1,"CNT:");//显示字符串
	
	while(1)
	{
		OLED_ShowNum(1,5,Num,5);
		OLED_ShowNum(2,5,Timer_GetCounter(),5);//看计数器
	}
}