key.h

LCD12864+51单片机 C语言例程 (此为在主程序

#define rowkey() (~P1)&0x0f
#define port P1
#define NULL 0
uchar CODE[]={'7','8','9','-',
			  '4','5','6','+',
			  '1','2','3','=',
			  '0','*','/','.'};
uchar getKey()
{
	uchar scan,keyin,col,row;
	scan=0xef;
	for(col=0;col<4;col++)
	{
		port=scan;
		keyin=rowkey();
		if(keyin!=0)
		{	
			for(row=0;row<4;row++)
			{
				if(keyin==(0x01)<<row)return CODE[col+row*4];
			}
		}
		scan=(scan<<1)|0x01;
	}
	return NULL;
}