key.h

已经调试通过的利用温度传感器18B20实现温度测量

#ifndef KEY_H
#define KEY_H
#include<reg52.h>
#include"delay.h"
void keyread()
{   
	unsigned char x,y,z;
	P2=0x0f;			//行扫描
	if(P2!=0x0f)
    {
		delay1(30);		
		x=P2;           //保存行扫描时有键按下时状态
		P2=0xf0;        //列扫描
        delay1(30);
		y=P2;           //保存列扫描时有键按下时状态
		z=x|y;          //取出键值
		switch (z)      //判断键值
		{
			case 0xe7: KEY=1;break; 
			case 0xd7: KEY=2;break; 
			case 0xb7: KEY=3;break; 
			case 0x77: KEY=4;break; 
			case 0xeb: KEY=5;break; 
			case 0xdb: KEY=6;break; 	
			case 0xbb: KEY=7;break; 
			case 0x7b: KEY=8;break;
			case 0xed: KEY=9;break; 
			case 0xdd: KEY=10;break; 
			case 0xbd: KEY=11;break; 
			case 0x7d: KEY=12;break;
			case 0xee: KEY=13;break;
			case 0xde: KEY=14;break; 
			case 0xbe: KEY=15;break; 
			case 0x7e: KEY=16;break;
		}
        delay1(30);
	}
    P2=0xff;
}
#endif