[嵌入式]【51单片机】定时器

Timer0.h

#ifndef __Timer0_H__
#define __Timer0_H__


void Timer0Init(void);

#endif

Timer0.c

#include <STC89C5xRC.H>


void Timer0Init(void)		//1毫秒@12.000MHz
{
	AUXR &= 0x7F;		//定时器时钟12T模式
	TMOD &= 0xF0;		//设置定时器模式
	TMOD |= 0x01;		//设置定时器模式
	TL0 = 0x18;		//设置定时初值
	TH0 = 0xFC;		//设置定时初值
	TF0 = 0;		//清除TF0标志
	TR0 = 1;		//定时器0开始计时
	ET0 = 1;
	EA = 1;
	PT0 = 0;
}

/*

//中断服务子程序
每隔一秒产生一次中断
void Timee0_Routine() interrupt 1{
	static unsigned int T0Count = 0;
	
	TL0 = 0x18;
	TH0 = 0xFC;	
	T0Count++;
	if(T0Count >= 1000){
		T0Count = 0;

	}
	
}

*/

main.c

#include <STC89C5xRC.H>
#include "Timer0.h"

void main(){
	
	Timer0Init();
	while(1){
		
	}
	
}

unsigned char arr[] = {0xFE,0xFD,0xFB,0xF7,0xEF,0xDF,0xBF,0x7F};
unsigned char index = 0;

//中断服务子程序
void Timee0_Routine() interrupt 1{
	static unsigned int T0Count = 0;
	
	TL0 = 0x18;
	TH0 = 0xFC;	
	T0Count++;
	if(T0Count >= 1000){
		T0Count = 0;
		P2 = arr[index];
		index++;
		if(index == 8)
			index = 0;
	}
	
}

首先体验了一下中断，就是主程序是一个while()循环，通过设置就会每隔一秒钟产生一次中断，产生中断就会停下当前的主程序，转而执行你写的中断服务子程序，执行完毕再回来执行主程序。

实验一

按下独立按键K1，流水灯方向向左流动
按下独立按键K2，流水灯方向向右流动

Timer0在上面展示过了，Delay也不展示了。
key.h

#ifndef __Key_H__
#define __Key_H__

unsigned char Key();
	
#endif

Key.c

#include <STC89C5xRC.H>
#include "Delay.h"

unsigned char Key(){
	unsigned char KeyNumber = 0;
	
	if(P31 == 0){Delay(20);while(P31 == 0);Delay(20);KeyNumber = 1;}
	if(P30 == 0){Delay(20);while(P30 == 0);Delay(20);KeyNumber = 2;}
	if(P32 == 0){Delay(20);while(P32 == 0);Delay(20);KeyNumber = 3;}
	if(P33 == 0){Delay(20);while(P33 == 0);Delay(20);KeyNumber = 4;}
	return KeyNumber;
}

main.c

#include <STC89C5xRC.H>
#include "Timer0.h"
#include "INTRINS.h"

#include "Key.h"
unsigned char KeyNum,LEDMode;
void main(){
	
	Timer0Init();
	P2 = 0xFE;
	LEDMode = 0;
	while(1){
		KeyNum = Key();
		if(KeyNum){
			if(KeyNum == 1){
				LEDMode = 0;
			}
			else if(KeyNum == 2){
				LEDMode = 1;
			}
			
		}
	}
	
}


//中断服务子程序
void Timee0_Routine() interrupt 1{
	static unsigned int T0Count = 0;
	
	TL0 = 0x18;
	TH0 = 0xFC;	
	T0Count++;
	if(T0Count >= 1000){
		T0Count = 0;
		if(LEDMode){
			P2 = _cror_(P2,1);		//循环右移
		}
		else{
			P2 = _crol_(P2,1);		//循环左移
		}

	}
	
}

总结：
如何判别每个独立按键的按下?
通过写一个函数，当每个按键按下，返回一个数字。
通过判断不同数字判断对应按键的按下。

实验二

实现一个计时器

#include <STC89C5xRC.H>
#include "Timer0.h"
#include "LCD1602.h"
unsigned int hour,minute,second;

void main(){
	LCD_Init();
	LCD_ShowString(1,1,"Clock!");
	hour = minute = second = 0;
	Timer0Init();
	while(1){
		LCD_ShowNum(2,1,hour,2);
		LCD_ShowString(2,3,":");
		LCD_ShowNum(2,4,minute,2);
		LCD_ShowString(2,6,":");
		LCD_ShowNum(2,7,second,2);
		
	}
	
}


//中断服务子程序
void Timee0_Routine() interrupt 1{
	static unsigned int T0Count = 0;
	
	TL0 = 0x18;
	TH0 = 0xFC;	
	T0Count++;
	if(T0Count >= 1000){
		T0Count = 0;
		second++;
		if(second == 60){
			second = 0;
			minute++;
		}
		if(minute == 60){
			minute = 0;
			hour++;
		}
		if(hour == 24){
			hour = 0;
		}

	}
	
}