text1.c

单片机快速入门原程序

#include <reg51.h>
#include<stdio.h>
Uart_Init();
int nKeyNumber;
sbit P10=0x90;
sbit P11=0x91;
sbit P12=0x92;
sbit P13=0x93;
sbit P14=0x94;
sbit P15=0x95;
sbit P16=0x96;
sbit P17=0x97;
main()
{ 	nKeyNumber=0xFF;
	P10=0;
	P11=0;
	P12=0;
	P13=0;
	EX0=1;
	EA=1;
	Uart_Init();
	while(1)
	{	EX0=1;
		if(nKeyNumber==0xFF) ;
			//printf("No key pressed\n");
		else 
			{
				printf("key %d  Pressed\n",nKeyNumber);
				nKeyNumber=0xFF;
				}
				
			

	}
}

Uart_Init()
	{SCON = 0x52;    /* 设置串行口控制寄存器SCON*/
	 TMOD = 0x20;    /* 12M时钟时波特率为2400  */
	 TCON = 0x69;    /* TCON */
	 TH1 =  0xf3;    /* TH1 */
	}

void int0() interrupt 0 using 0
{
int i,j;
int Pin1;	
	EX0=0;            /* 关中断*/
for(i=0;i<4;i++)
	for(j=0;j<4;j++)
		{
	P1=0xFF&(~(0x01<<(3-i)));
		Pin1=P1;
			if(((Pin1>>(4+j))&0x01)==0)
				{nKeyNumber=i+j*4;
				return;
			
				}
		}
EX0=1;


}