1 #include <reg52.h>
  2 #define uint unsigned int 
  3 #define uchar unsigned char
  4     uchar keynum=0;
  5 uchar duan[]={0xc0,~0x06,~0x5b,~0x4f,~0x66,~0x6d,~0x7d,~0x07,~0x7f,~0x6f,~0x77,~0x7c,~0x39,~0x5e,~0x79,~0x71};
  6 /*              0     1    2    3      4     5     6     7     8    9       A    B     C     D      E     F       */
  7 void delay()
  8 {
  9   int i=200;
 10     while(i--);
 11 }
 12 void key44scan(void)
 13 {
 14   uchar t;
 15     P2=0xfe;
 16     t=P2;
 17     t=t&0xf0;
 18     if(t!=0xf0)
 19     {
 20       delay();
 21         t=P2;
 22         t=t&0xf0;
 23     if(t!=0xf0)
 24     {
 25         t=P2;
 26         switch(t)
 27         {
 28             case 0xee:keynum=0;break;
 29             case 0xde:keynum=4;break;
 30           case 0xbe:keynum=7;break;
 31           case 0x7e:keynum=12;break;
 32      }
 33         P3=duan[keynum];
 34      while(t!=0xf0)
 35      {
 36      t=P2;
 37         t=t&0xf0;     
 38      }
 39  }
 40 }
 41 /* *************************************************************************************** */
 42   P2=0xfd;
 43     t=P2;
 44     t=t&0xf0;
 45     if(t!=0xf0)
 46     {
 47         delay();
 48         t=P2;
 49         t=t&0xf0;
 50     if(t!=0xf0)
 51     {
 52         t=P2;
 53         switch(t)
 54         {
 55           case 0xed:keynum=1;break;
 56             case 0xdd:keynum=5;break;
 57           case 0xbd:keynum=9;break;
 58           case 0x7d:keynum=13;break;
 59         }
 60       P3=duan[keynum];
 61         while(t!=0xf0)
 62         {
 63     t=P2;
 64     t=t&0xf0;
 65         }
 66     }
 67 }
 68 /* *************************************************************************************** */
 69   P2=0xfb;
 70     t=P2;
 71     t=t&0xf0;
 72     if(t!=0xf0)
 73     {
 74     delay();
 75     t=P2;
 76     t=t&0xf0;    
 77     if(t!=0xf0)
 78     {
 79         t=P2;
 80     switch(t)
 81     {
 82           case 0xeb:keynum=2;break;
 83             case 0xdb:keynum=6;break;
 84           case 0xbb:keynum=10;break;
 85           case 0x7b:keynum=14;break;

 86       }
 87       P3=duan[keynum];
 88         while(t!=0xf0)
 89         {
 90     t=P2;
 91     t=t&0xf0;
 92       }
 93    }
 94     }
 95 /* *************************************************************************************** */
 96     
 97   P2=0xf7;
 98     t=P2;
 99     t=t&0xf0;
100     if(t!=0xf0)
101     {
102     delay();
103     t=P2;
104     t=t&0xf0;    
105     if(t!=0xf0)
106     {
107     t=P2;
108     switch(t)
109     {
110           case 0xe7:keynum=3;break;
111             case 0xd7:keynum=7;break;
112           case 0xb7:keynum=11;break;
113           case 0x77:keynum=15;break;
114       }
115         P3=duan[keynum];
116         while(t!=0xf0)
117         {
118             t=P2;
119        t=t&0xf0;
120             }
121             }
122         }
123     }
124 /* *************************************************************************************** */
125     
126     main()
127     {
128     
129     while(1)
130     {
131         key44scan();
132     }
133 }
134 
135
136 137 138 139 140 141 142 143 144 145 146