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
}
}