key.h

单片机的按键扫描程序

/*******************检测到的4+4键盘键值（0，1，2......15)********************************************************************************/
unsigned char key;
/****************************************************************************************************************************************/

 
 /******************设置检测到的4+4键盘键值在LCD1602上显示的字符**************************************************************************/   
unsigned char getkey,sender,counterOne,counterTwo;  //检测到的4+4键盘键值需要在LCD1602上显示的代码地址存放处
unsigned char code keywords[]={0x30,0x31,0x32,0x33,	//0,1,2,3,	对应的在LCD1602上的代码地址
                               0x34,0x35,0x36,0x37,	//4,5,6,7,  
                               0x38,0x39,0x41,0x42,	//8,9,A,B
                               0x43,0x44,0x45,0x46};//C,D,E,F
/****************************************************************************************************************************************/
uchar code initialKeyboardCode[] = { 0xef, 0xdf, 0xbf, 0x7f }; //Set the initial keyboard code.
uchar code getKeyboardCode[] = { 0xee, 0xed, 0xeb, 0xe7, 0xde, 0xdd, 0xdb, 0xd7, //When the keyboard pressed
0xbe, 0xbd, 0xbb, 0xb7, 0x7e, 0x7d, 0x7b, 0x77 }; // down ,the mcu will get one of them.						

unsigned char i,j,temp;


void searchkey(void) //键值搜索子程序
{	
	getkey=0;
	 sender = 0x00;
	 counterOne = 0x00;
	 counterTwo = 0x00;
	for(counterOne=0x00; counterOne<4; counterOne++)
	{
		P0 = initialKeyboardCode[counterOne]; //Load the initialKeyboardCode
		sender = P0; //Get the keyboardCode when the keyboard press down
		for(i=50;i>0;i--)
          for(j=200;j>0;j--);//perhaps a delay here.
		for(counterTwo=0; counterTwo<16; counterTwo++)
		{
		
			if(sender==getKeyboardCode[counterTwo]) //When a geyKeyboardCode equal to the sender '
			{
				while(sender==P0);
		   		
				getkey=keywords[counterTwo];//Then load the display code from the theActioncode
				//You can write you control functions here too.
			}
		} 
	}
}



uchar keyb()
{  getkey=0;
   while(getkey==0)
    {
    searchkey();
    }
    return(getkey);
}