51单片机定时器封装

1万 · 2024-11-25 11:08

简介
介绍：仿javascript的setInterval(callback,delay)实现封装的定时器函数。

文件：timer.c和timer.h

API
定时器初始化
void timer_init(unsigned char timers);

// 单独初始化定时器1
timer_init(TIMER1);
// 同时初始化定时器0和1
timer_init(TIMER0|TIMER1);
添加定时调用事件
char timer_add_event(unsigned char timer_id, void (*callback)(void), unsigned short ms);

// 初始化定时器id，未绑定事件时为-1
char timer = -1;
// 在定时器0 添加函数事件callback，每 500ms 调用一次，不会立即调用。
timer = timer_add_event(0, callback, 500);

// 外部函数定义格式示例
void callback(){
// 执行代码
}
删除定时调用事件
char timer_remove_event(unsigned char timer_id, char id);

// 初始化定时器id，未绑定事件时为-1
char timer = -1;

// 在定时器0 添加函数事件callback，每 500ms 调用一次，不会立即调用。
timer = timer_add_event(0, callback, 500);

// 删除timer绑定的函数事件，返回值：-1
timer = timer_remove_event(0,timer);
LED示例
key开关控制led闪烁

#include <REG52.H>
#include "timer.h"
sbit led = P2^0; // led灯
sbit key = P3^1; // 独立按键
void delay_ms(unsigned int ms){
unsigned int i,j;
for(i = 0; i < ms; i++)
      for(j = 0; j < 110; j++);
}
void led_change(){
led = ~led;
}
void main()
{
char timer = -1;
timer_init(TIMER0); // 定时器0初始化
while(1){
      if (key == 0)
      {
         delay_ms(10);
         if (key == 0)
         {
            if(timer==-1){ // 如果定时器未绑定事件，则添加事件
                  timer = timer_add_event(0, led_change, 500); // 添加定时器事件
            }else{
                  timer = timer_remove_event(0,timer); // 移除定时器事件
            }
            while (key == 0);
         }
      }

}
}

注意
如果出现此代码所在文件触发的“ADDRESS SPACE OVERFLOW”，减少EVENT_MAX或TIMER_MAX。测试数据：普中51测试两种模式切换代码，timer_events最大能够定义5个Timer_Event_Type，问题疑似内存不足（不确定）。

函数文件
timer.h
/*
* @Author: VB9331 vb9331@qq.com
* @Date: 2024-11-20 00:00:00
* @LastEditors: VB9331 vb9331@qq.com
* @LastEditTime: 2024-11-20 00:55:27
* @Description: 定时器封装
* Copyright (c) 2024 by VB9331 , All Rights Reserved.
*/
#ifndef __TIMER_H__
#define __TIMER_H__

#define NULL ((void *)0)
enum {
TIMER0 = 1,
TIMER1
};

void timer_init(unsigned char timers);
char timer_add_event(unsigned char timer_id, void (*callback)(void), unsigned short ms);
char timer_remove_event(unsigned char timer_id, char id);

#endif

timer.c
/*
* @Author: VB9331 vb9331@qq.com
* @Date: 2024-11-20 00:00:00
* @LastEditors: VB9331 vb9331@qq.com
* @LastEditTime: 2024-11-20 00:55:27
* @Description: 定时器封装
* Copyright (c) 2024 by VB9331 , All Rights Reserved.
*/
#include <REG52.H>
#include "timer.h"

#define TIMER_MAX 2 // 定时器最大数量
#define EVENT_MAX 2 // 每个定时器能存储的最大事件数量

typedef struct _Timer_Event_Type {
unsigned char enabled; // 是否绑定
unsigned short delay; // 延时时间
void (*fun)(void); // 回调函数
unsigned short begin_time; // 记录开始时间，用于计算已绑定时间
} Timer_Event_Type;

Timer_Event_Type timer_events[TIMER_MAX][EVENT_MAX];

char cur_id_max[TIMER_MAX];

unsigned short action_time[2] = {0, 0}; // 定时器已启动时间

void timer_init(unsigned char timers)
{
TMOD &= ((0xF00 >> (timers & TIMER0)) | (0xF00 >> (timers & TIMER1))) & 0xFF;

EA = 1; // 打开总中断
if (timers & TIMER0) {
      TMOD |= 0x01;
      TH0 = 0XFC;
      TL0 = 0X18;
      TF0 = 0; // interrupt sign
      ET0 = 1; // 打开定时器0中断允许
      TR0 = 1; // 打开定时器
      PT0 = 0; // priority level
}
if (timers & TIMER1) {
      TMOD |= 0x10;
      TH1 = 0XFC;
      TL1 = 0X18;
      TF1 = 0; // interrupt sign
      ET1 = 1; // 打开定时器1中断允许
      TR1 = 1; // 打开定时器
      PT1 = 1; // priority level
}
}

// add timer event
char timer_add_event(unsigned char timer_id, void (*callback)(void), unsigned short ms)
{
unsigned char i;
char id;
Timer_Event_Type new_event;

// catch_begin
// 非法值直接退出
if (callback == NULL) {
      return -1;
}
// 负数和0延时调为1ms
ms <= 0 ? ms = 1 : 0;
// catch_end

// find available id
for (i = 0; i <= cur_id_max[timer_id] && timer_events[timer_id].enabled; i++);
id = i;
if (id >= EVENT_MAX) { // catch
      return -1;
}
if (id > cur_id_max[timer_id]) {
      cur_id_max[timer_id] = id;
}

new_event.enabled       = 1;
new_event.delay          = ms;
new_event.fun             = callback;
new_event.begin_time    = action_time[timer_id]; // +1 防止立即触发
timer_events[timer_id][id] = new_event;
return id;
}

char timer_remove_event(unsigned char timer_id, char id)
{
if (id < 0 || id > cur_id_max[timer_id]) { // catch
      return id;
}
timer_events[timer_id][id].enabled = 0;
timer_events[timer_id][id].delay    = 0;
timer_events[timer_id][id].fun       = NULL;
timer_events[timer_id][id].begin_time = 0;
if (id == cur_id_max[timer_id]) {
      cur_id_max[timer_id]--;
}
return -1;
}

void time0_handler(void) interrupt 1 // 定时器0中断函数
{

const unsigned char timer_id = 0; // 定时器id

unsigned char i;
TH0 = (65536 - 1000) / 256; // 1ms 中断一次
TL0 = (65536 - 1000) % 256;
action_time[0]++; // 定时器0已启动时间+1，放在函数前端防止立即触发

for (i = 0; i <= cur_id_max[timer_id]; i++) {
      if (timer_events[timer_id].enabled == 0) {
         continue;
      }
      if (((action_time[0] - timer_events[timer_id].begin_time) % timer_events[timer_id].delay) == 0) {
         timer_events[timer_id].fun(); // TODO: Whether to add arguments about the timer object to this function.
      }
}
}

void time1_handler() interrupt 3 // 定时器1中断函数
{
const unsigned char timer_id = 1;

unsigned char i;
TH1 = (65536 - 1000) / 256;
TL1 = (65536 - 1000) % 256;
action_time[1]++;

for (i = 0; i <= cur_id_max[timer_id]; i++) {
      if (timer_events[timer_id].enabled == 0) {
         continue;
      }

      if (((action_time[1] - timer_events[timer_id].begin_time) % timer_events[timer_id].delay) == 0) {
         timer_events[timer_id].fun(); // TODO: Whether to add arguments about the timer object to this function.
      }
}
}

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                        版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。

原文链接：https://blog.csdn.net/qq_47019630/article/details/143898493

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