stc12c5a60s 按鍵掃描程式正規用法

按鍵掃描程式正規用法

main.c

#include <reg52.h>

sfr AUXR = 0x8e;

sbit KEY = P0^0;
sbit LED = P0^1;

void Timer0Init(void)		//2毫秒@11.0592MHz
{
	AUXR &= 0x7F;		//定時器時鐘12T模式
	TMOD &= 0xF0;		//設定定時器模式
	TL0 = 0xCD;		//設定定時初值
	TH0 = 0xF8;		//設定定時初值
	TF0 = 0;		//清除TF0标志
	TR0 = 1;		//定時器0開始計時
}

void key_scan()
{
	static unsigned char state_cnt;

	switch(state_cnt)
	{
		 case 0x00: if(KEY == 0) //有按鍵被按下
		 			{
						state_cnt = 0x01;
						break;
					}
		 case 0x01: if(KEY == 0) //确定被按下
		 			{
						state_cnt = 0x02;
						LED = ~LED;		 //執行按鍵對應操作
						break;
					}
					else   //沒有被被按下，重新開始檢測 
					{
						state_cnt = 0x00;
						break;
					}
		  case 0x02: if(KEY == 1)  //按鍵被釋放
		  			 {
					 	state_cnt = 0x00; //一個完整的按鍵觸發、執行、釋放的過程完成
						break;
					 }
		  default: break;
	}
}

void main()
{
	LED = 1;
	KEY = 1;
	EA = 1;
	ET0 = 1;
	Timer0Init();

	while(1);
}

void Timer0_routine() interrupt 1
{
	static unsigned char cnt_2ms;
		
	cnt_2ms ++; //計數
	if(cnt_2ms == 5) //調用按鍵掃描函數
	{
		key_scan();
		cnt_2ms = 0;
	}

}