keyboard.c

数字频率合成器DDS9851控制系统的单片机源代码

////////////////////////////////////////////////////////////////////////////
//////////////////////////////
//	  0   1   2		    P1^n//
//----------------- 3 ///////
//	  |	  |	  |		  ///
//----------------- 4 ///
//	  |	  |   |		  //
//----------------- 5 ///
//	  |	  |	  |		  //
//----------------- 6 ///
////////////////////////
//////////////////////////
////////////////////////////////////////////////////////////////////////////
#include <reg52.h>

#define 	keyboard	P1			 //管脚定义

extern	void	delay_ms(unsigned char time);

unsigned char check_key(void)	 //按纽检查函数，返回键码  取消（10）  确认（11）
{
  unsigned char readkey;
  unsigned char xtemp,ytemp;
  while(1)
  {
  	keyboard = 0x07;
  	xtemp = keyboard & 0x07;
  	if(xtemp == 0x07) continue;
	keyboard = 0xf8;
	ytemp = keyboard & 0xf8;
	readkey = xtemp | ytemp;
	readkey =~readkey;

	switch(readkey)
	{
		case 0x09: readkey = 1;break;
		case 0x0a: readkey = 2;break;
		case 0x0c: readkey = 3;break;
		case 0x11: readkey = 4;break;
		case 0x12: readkey = 5;break;
		case 0x14: readkey = 6;break;
		case 0x21: readkey = 7;break;
		case 0x22: readkey = 8;break;
		case 0x24: readkey = 9;break;
		case 0x41: readkey = 10;break;
		case 0x42: readkey = 0;break;
		case 0x44: readkey = 11;break;
	}
	keyboard = 0x07;
	while(keyboard != 0x07);		//等待按纽松开
	return readkey;
  }
}