本例介绍一种用LED制作的电脑电子钟(电脑万年历)。其制作完成装潢后的照片如下图:
上图中,年、月、日及时间选用的是1.2寸共阳数码管,星期选用的是2.3寸数码管,温度选用的是0.5寸数码管,也可根据个人的爱好选用不同规格的数码管。原理图如下图所示:
上图中,CPU选用的是AT89C2051,时钟芯片选用的是Dallas公司的DS1302,温度传感器选用的是Dallas公司的数字温度传感器DS1820,显示驱动芯片选用的是德州仪器公司的TPIC6B595,也可选用与其兼容的芯片NC595或国产的AMT9595。整个电子钟用两个键来调节时间和日期。一个是位选键,一个是数字调节键。按一下位选键,头两位数字开始闪动,进入设定调节状态,此时按数字调节键,当前闪动位的数字就可改变。全部参数调节完后,五秒钟内没有任何键按下,则数字停止闪动,退出设定调节状态。
源程序清单如下(无温度显示程序):
start:do;$include(reg51.dcl)declare (sclk,io,rst) bit at (0b3h) register; /* p33,p34,p35 */declare (command,data,n,temp1,num) byte;declare a(9) byte;declare ab(6) byte;declare aco(11) byte constant (0fdh,60h,0dah,0f2h,66h,0b6h,0beh,0e0h,0feh,0f6h,00h);declare week(11) byte constant (0edh,028h,0dch,7ch,39h,75h,0f5h,2ch,0fdh,7dh,00h);declare da literally 'p15',clk literally 'p16',ale literally 'p17',mk literally 'p11',sk literally 'p12';clear:procedure;sclk=0;io=0;rst=0;end clear;send1302:procedure(comm);declare (i,comm) byte;do i=0 to 7;comm=scr(comm,1);io=cy;call time(1);sclk=0;call time(1);sclk=1;end;end send1302;wbyt1:procedure(com,dat);/*字节写过程*/declare (com,dat) byte;call clear;rst=1;call send1302(com);call send1302(dat);call clear;end wbyt1;wbyt8:procedure;/*时钟多字节突发模式写过程*/declare j byte;call clear;a(7)=A(6);a(6)=a(0);rst=1;call send1302(command);do j=1 to 8;call send1302(a(j));end;call clear;end wbyt8;RBYT1:PROCEDURE;DECLARE I BYTE;CALL CLEAR;RST=1;call send1302(0c1h);IO=1;DO I=0 TO 7;SCLK=1;SCLK=0;CY=IO;N=SCR(N,1);END;A(8)=N;CALL CLEAR;END RBYT1;send595:procedure;declare k byte;do k=0 to 7;data=scr(data,1);da=cy;clk=1;clk=0;end;end send595;send595_1:procedure;declare k byte;do k=0 to 7;data=scr(data,1);da1=cy;clk1=1;clk1=0;end;end send595_1;rb1:procedure(abc,j);DECLARE (I,j,abc) BYTE;CALL CLEAR;RST=1;call send1302(abc);IO=1;DO I=0 TO 7;SCLK=1;SCLK=0;CY=IO;N=SCR(N,1);END;ab(j)=N;ab(j)=dec(ab(j));CALL CLEAR;end rb1;rbyt6:procedure;call rb1(0f1h,0);call rb1(0f3h,1);call rb1(0f5h,2);call rb1(0f7h,3);call rb1(0f9h,4);call rb1(0fbh,5);call rb1(0fdh,6);end rbyt6;wbyt6:procedure;call wbyt1(8eh,0);/* write enable */call wbyt1(0f0h,ab(0));call wbyt1(0f2h,ab(1));call wbyt1(0f4h,ab(2));call wbyt1(0f6h,ab(3));call wbyt1(0f8h,ab(4));call wbyt1(0fah,ab(5));call wbyt1(0fch,ab(6));call wbyt1(8eh,80h);/* write disable */end wbyt6;rbyt8:procedure;/*时钟多字节突发模式读过程*/declare (i,j) byte;call clear;rst=1;call send1302(command);io=1;do j=1 to 8;do i=0 to 7;sclk=1;call time(1);sclk=0;cy=io;n=scr(n,1);end;a(j)=n;end;call clear;a(0)=a(6);a(6)=A(7);a(0)=a(0) and 0fh;if a(0)>6 then a(0)=0;CALL RBYT1;if (a(1)=0 and a(2)=0 and a(3)=0) thendo;do num=0 to 35;call time(250);end;temp1=1;end;if temp1=1 thendo;temp1=0;ab(4)=ab(4)+1;if ab(4)>99h thendo;ab(4)=0;ab(5)=ab(5)+1;if ab(5)>99h then ab(5)=0;end;call wbyt6;end;end rbyt8;display:procedure; /*jieya,yima,fasong*/declare (i,n,m) byte;n=a(0) and 0fh; /* send week */data=week(n);call send595;n=a(4);/* send date */n=n and 0fh;data=aco(n);call send595;n=a(4);n=shr(n,4);data=aco(n);call send595;do i=1 to 3; /* send second,minute,hour */n=a(i);n=n and 0fh;data=aco(n);call send595;n=a(i);n=shr(n,4);data=aco(n);call send595;end;do i=5 to 6; /* send month,year */n=a(i);n=n and 0fh;data=aco(n);call send595;n=a(i);n=shr(n,4);data=aco(n);call send595;end;n=a(8);/* send 19 or 20 */n=n and 0fh;data=aco(n);call send595;n=a(8);n=shr(n,4);data=aco(n);call send595;do m=0 to 5;n=ab(m);n=n and 0fh;data=aco(n);call send595_1;n=ab(m);n=shr(n,4);data=aco(n);call send595_1;end;ale=0;ale=1;end display;beginset:procedure;a(0)=06h;a(1)=58h;a(2)=59h;a(3)=23h;a(4)=30h;a(5)=06h;a(6)=97h;a(7)=00;a(8)=19h; /* set date/time (1997,7,1,8:00:00,week 3) */call wbyt1(8eh,0);/* write enable*/call wbyt1(80h,00h);/* start colock */call wbyt1(0beh,0abh);/*两个二极管与8K电阻串联充电*/command=0beh; /* write colock/date */call wbyt8;call wbyt1(0c0h,a(8));call wbyt1(8eh,80h);/* set write protect bit */end beginset;key:procedure;declare (i,time1,k1,tem) byte;call time(100);k1=7;time1=30;if mk=0 thendo;do while time1>0;week: if k1=0 thendo;do i=0 to 5;/* call hz(a(0));*/end;do i=0 to 3;/* call hz0; */end;end;tem=a(k1);if k1=7 then tem=a(8);a(k1)=0aah;if k1=7 then a(8)=0aah;call display;call time(254);call time (254);a(k1)=tem;if k1=7 then a(8)=tem;call display;call time(254);call time(254);call time(254);time1=time1-1;if mk=0 thendo;call time(100);/*MOD KEY PROCESS*/TIME1=30;IF MK=0 THENDO;k1=k1-1;DO WHILE K1=0FFH;K1=7;END;END;end;IF SK=0 THENDO;CALL TIME(100);/*SET KEY PROCESS*/TIME1=30;IF SK=0 THENDO;tem=tem+1;tem=dec(tem);DO CASE K1;DO WHILE tem=7;/*week*/tem=0;END;DO WHILE tem=60H;/*scond*/tem=0;END;DO WHILE tem=60H;/*minute*/tem=0;END;DO WHILE tem=24H;/*hour*/tem=0;END;DO WHILE tem=32H;/*date*/tem=1;END;DO WHILE tem=13H;/*month*/tem=1;END;DO while tem=100h; /* YEAR */tem=00;END;DO WHILE TEM>=21H;tem=19H;END;END;A(K1)=tem;if k1=7 then a(8)=tem;END;END;END;END;end key;main$program:mk=1;sk=1;temp1=0;num=0;p32=1;if sk=0 then call beginset;clk=0;da=0;ale=1;loop:do while mk=1 ;if a(0)>6 then a(0)=0;command=0bfh;call rbyt8;call display;do while mk=0;call key;call wbyt1(8eh,0);command=0beh;call wbyt8;call wbyt1(0C0H,A(8));call wbyt1(8eh,80h);end;end;goto loop;end start;