/*  3x4矩陣鍵盤的掃描程序
按相應的按鍵，數碼管顯示相應的數字，星號鍵和井號鍵分別顯示為E和F
*********************************
Created by 芮亞楠 
*********************************
測試通過*/ 

/*此程序不包含多個按鍵被按下的情況*/
#include


unsigned char code table[]={0xC0,0xF9,0xA4,0xB0,0x99, //0~4
       0x92,0x82,0xF8,0x80,0x90, //5~9
       0x88,0x83,0xA7,0xA1,0x86,0x8E}; //A~F

void KeyScan();
void delay10ms(unsigned char time);
void Dispaly(unsigned char k);

unsigned char key,temp;

void main() //主程序
{
 while(1)
 {
  KeyScan();
 }
}

/*
      P1_7   P1_6   P1_5 
        |      |
P1_3--------------------------
        |      |
P1_2--------------------------
        |      |
P1_1--------------------------
        |      |
P1_0--------------------------
        |      |
*/

void KeyScan() //按鍵掃描子程序
{
 P1=0xFF;  //使用P1口作為四行三列的矩陣，初始化全部置高
 P1_3=0;  //先掃描第1行，第一行置零 
 temp=P1;  //當前值為1111 1011
 temp&=0xF0; //如果沒有按鍵按下，則為 1111 0000
 if(temp !=0xF0) //不為F0，說明P1_4 - P1_6有按鍵按下
 {
  delay10ms(1); //去除抖動
  temp=P1;
  temp&=0xF0;
  if(temp !=0xF0)
  {
   temp=P1;
   temp&=0xF0;

   switch(temp)
   {
   case 0x70: //表示P1_7按下
    key=1;break;
   case 0xB0: //表示P1_6按下
    key=2;break;
   case 0xD0: //表示P1_5按下
    key=3;break;
   }
   Dispaly(key);
  }
 }

 P1=0xFF;
 P1_2=0;
 temp=P1;
 temp&=0xF0;
 if(temp !=0xF0)
 {
  delay10ms(1);
  temp=P1;
  temp&=0xF0;
  if(temp !=0xF0)
  {
   temp=P1;
   temp&=0xF0;

   switch(temp)
   {
   case 0x70:
    key=4;break;
   case 0xB0:
    key=5;break;
   case 0xD0:
    key=6;break;
   }
   Dispaly(key);
  }
 }

 P1=0xFF;
 P1_1=0;
 temp=P1;
 temp&=0xF0;
 if(temp !=0xF0)
 {
  delay10ms(1);
  temp=P1;
  temp&=0xF0;
  if(temp !=0xF0)
  {
   temp=P1;
   temp&=0xF0;

   switch(temp)
   {
   case 0x70:
    key=7;break;
   case 0xB0:
    key=8;break;
   case 0xD0:
    key=9;break;
   }
   Dispaly(key);
  }
 }

 P1=0xFF;
 P1_0=0;
 temp=P1;
 temp&=0xF0;
 if(temp !=0xF0)
 {
  delay10ms(1);
  temp=P1;
  temp&=0xF0;
  if(temp !=0xF0)
  {
   temp=P1;
   temp&=0xF0;

   switch(temp)
   {
   case 0x70:
    key=14;break;
   case 0xB0:
    key=0;break;
   case 0xD0:
    key=15;break;
   }
   Dispaly(key);
  }
 }
}

//延時程序
void delay10ms(unsigned char time)
{
 unsigned char a,b,c;
 for(a=0;a  for(b=0;b<10;b++)
   for(c=0;c<120;c++)
   ;
}

void Dispaly(unsigned char k) //顯示程序
{
 P0=table[k];
 P2_1=0;
}