keyscan.c

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#include <reg52.h>
sbit key1=P3^4;
sbit dula=P2^6;
sbit wela=P2^7;
#define uint unsigned int
#define uchar unsigned char
uchar num,temp,num1;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71,0};
void delay(uint z);
uchar keyscan();
void main()
{
	dula=1;
	P0=0;
	dula=0;
	wela=1;
	P0=0xc0;
	wela=0;
		
	while(1)
	{
		num1=keyscan();
		dula=1;
		P0=table[num1-1];
		dula=0;
	}
}	
uchar keyscan()
{
		P3=0xfe;
		temp=P3;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			delay(5);
			temp=P3;
			temp=temp&0xf0;
			while(temp!=0xf0)
			{
				temp=P3;
				switch(temp)
					{
						case 0xee:num=1;
							break;
						case 0xde:num=2;
							break;
						case 0xbe:num=3;
							break;
						case 0x7e:num=4;
							break;
					}
				while(temp!=0xf0)
				{
					temp=P3;
					temp=temp&0xf0;
				}			
			}
		}

		P3=0xfd;
		temp=P3;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			delay(5);
			temp=P3;
			temp=temp&0xf0;
			while(temp!=0xf0)
			{
				temp=P3;
				switch(temp)
					{
						case 0xed:num=5;
							break;
						case 0xdd:num=6;
							break;
						case 0xbd:num=7;
							break;
						case 0x7d:num=8;
							break;
					}
				while(temp!=0xf0)
				{
					temp=P3;
					temp=temp&0xf0;
				}							
			}
		}	

		P3=0xfb;
		temp=P3;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			delay(5);
			temp=P3;
			temp=temp&0xf0;
			while(temp!=0xf0)
			{
				temp=P3;
				switch(temp)
					{
						case 0xeb:num=9;
							break;
						case 0xdb:num=10;
							break;
						case 0xbb:num=11;
							break;
						case 0x7b:num=12;
							break;
					}
				while(temp!=0xf0)
				{
					temp=P3;
					temp=temp&0xf0;
				}	
			}
		}	

		P3=0xf7;
		temp=P3;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			delay(5);
			temp=P3;
			temp=temp&0xf0;
			while(temp!=0xf0)
			{
				temp=P3;
				switch(temp)
					{
						case 0xe7:num=13;
							break;
						case 0xd7:num=14;
							break;
						case 0xb7:num=15;
							break;
						case 0x77:num=16;
							break;
					}
				while(temp!=0xf0)
				{
					temp=P3;
					temp=temp&0xf0;
				}	
			}
		}		
return num;	
}
void delay(uint z)
{
	uint x,y;
	for(x=z;x>0;x--)
		for(y=110;y>0;y--);
}