标题: 单片机扫描方式的键盘输入实验 [打印本页]
作者: liuda    时间: 2015-1-21 23:30
标题: 单片机扫描方式的键盘输入实验
是用51hei单片机开发板 电路图详见：http://www.51hei.com/f/51hei-5.pdf  的数码管部分， 用2个74hc573 锁存，p0口作为数据口 ，注意图中要改一下p3.6和p3.7分别是段和位的锁存端口.P2口上面是按键 p1口上面是8个led灯.
  1. #include<reg52.h>
  2. #define uchar unsigned char
  3. #define uint unsigned int
  4. uchar code DIS_SEG7[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
  5. uchar code DIS_BIT[8]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
  6. uchar code SKEY[16]={1,2,3,10,4,5,6,11,7,8,9,12,14,0,15,13};
  7. uchar code act[4]={0xfe,0xfd,0xfb,0xf7};
  8. sbit D=P3^6;
  9. sbit V=P3^7;
  10. //=======================
  11. void delay(uint k)
  12. {
  13. uint data i,j;
  14. for(i=0;i<k;i++){
  15. for(j=0;j<121;j++)
  16. {;}}
  17. }
  18. //==============
  19. void delay10ms(void)
  20. {
  21. uint data i,j;
  22. for(i=0;i<10;i++){
  23. for(j=0;j<121;j++)
  24. {;}}
  25. }
  26. //================
  27. char scan_key(void)
  28. {
  29. uchar i,j,in,ini,inj;
  30. bit find=0;
  31. for(i=0;i<4;i++)
  32. {
  33. P1=act[i];
  34. delay10ms();
  35. in=P1;
  36. in=in>>4;
  37. in=in|0xf0;
  38. for(j=0;j<4;j++)
  39. {
  40. if(act[j]==in)
  41. {find=1;
  42. inj=j;ini=i;
  43.        }
  44. }
  45.   }
  46. if(find==0)return-1;
  47. return (ini*4+inj);
  48. }
  49. //============
  50. void main(void)
  51. {char c;
  52. uchar key_value;
  53. D=1;P0=0xff;D=0;V=1;P0=0xfe;V=0;
  54. while(1)
  55. {
  56. delay(5000);
  57. c=scan_key();
  58. if(c!=-1)key_value=SKEY[c];
  59. if(key_value==1){D=1;P0=0xff;D=0;V=1;P0=0xff;V=0;}
  60. }
  61. }
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