基于51单片机的时钟调整系统.docx

单片机研究性教学题 目：基于51单片机的时钟调整系统学 院：机电学院提交日期：2012年 5 月 29 日前言 时钟是人类生活中必不可少的工具，从挂式的、手机上的、电脑上的以及手表等。学完单片机后，我们基本了解到了单片机时钟的工作原理以及实现方式。借此研究性教学的机会，我们打算用单片机的知识完成对单片机电子时钟的设计以及制作。该设计不仅可以锻炼我们的动手能力，而且可以加深我们对单片机的认识和激发我们对机电控制的探索。基于单片机的数字时钟采用独立式按键来进行时间调整， MAX7219、AT89C51是其主要芯片，并利用数码管LED动态显示“时”，“分”，“秒”的现代计时装置。与传统机械表相比，它具有走时精确，显示直观等特点。它的计时周期为24小时，显满刻度为“23时59分59秒”。它不仅仅可以显示时间，还可以显示星期。总而言之该系统同时具有硬件设计简单，工作稳定性高，价格低廉等优点。关键词:时钟 、LED显示、MAX7219、AT89C51、点阵LED显示器一、 任务设计一个单片机时钟显示调整系统，其中扩展连接6个8段LED数码管显示器，利用MAX7219显示驱动器驱动LED用于时钟显示和调整，利用8*8点阵LED显示器显示星期。连接3个独立式按键分别控制系统的显示模式切换和时间值增减调整。二、 方案硬件选择：MAX7219驱动器、AT89C51单片机、6位LED显示器、8*8点阵LED、74LS14、74LS245、电阻、CAP电容、PCELECT4U763V电容、晶振、按键、电源三、 功能要求1、 六位数码管显示时、分、秒，以24小时运算2、 点阵LED显示星期3、 可实现对秒、分、时、星期的加减调整四、 程序设计1、主程序设计中计时采用定时器T0中断完成。主程序循环调用显示子程序和查键，当端口有开关按下时，转入相应的功能程序。流程图如图1所示。图1 主程序流程4、 显示子程序 显示由MAX7219驱动的六位显示器和点阵LED显示器共同完成，首先对其进行初始化，然后用单片机控制显示器显示。MAX7219驱动器显示流程图图2 显示子程序5、 定时器T0中断服务程序定时溢出中断周期设为50MS，中断进入后先进行定时中断初值校正，当中断累加到20次时，对秒计数单元进行加1操作。时钟最大计时值为23时59分59秒。在计数单元中，采用十进制BCD码计数，满十进位。流程图如图3所示在程序中采用12MHZ晶振频率，精度为1MS，定时初值为50MS，用循环程序进行20次循环可到1S。当1S到时调用加1程序并判断秒、分是否为60，当秒为60时，秒清零，分加1；当分为60时，分清零。当时满24时，星期加1，时清零，星期由1至7循环。终端结束时，计时单元数据移入对应显示单元。三、按键设置本时钟设置P1.0，P1.1，P1.2接3个按钮开关，用于调时。其中P1.0用于选择调时模式（对星期，小时，分钟，秒的选择），P1.1完成对所选的项目进行增一的操作，P1.2完成对所选项目进行减一的操作。四、程序KEY1BITP1.0KEY2BITP1.1KEY3BITP1.2CLKBITP1.3LOADBITP1.4DINBITP1.5SECONDDATA30HMINUTEDATA31HHOURDATA32HDAY DATA 33HORG0000HAJMPMAINORG000BHAJMPTIMER0MAIN:MOVSP,#60HMOVTMOD,#01HMOVTH0,#0B1HMOVTL0,#0E0HSETBET0SETBEAMOVR2,#50SETBTR0MOVSECOND,#00HMOVMINUTE,#00HMOVHOUR,#00H MOV DAY,#00HMOVA,HOURANLA,#0F0HSWAPAMOV79H,AMOVA,HOURANLA,#0FHMOV7AH,AMOVA,MINUTEANLA,#0F0HSWAPAMOV7BH,AMOVA, MINUTEANLA,#0FHMOV7CH,AMOVA,SECONDANLA,#0F0HSWAPAMOV7DH,AMOVA,SECONDANLA,#0FHMOV7EH,AMOVR3,#00HACALLINT7219 LOOP:ACALLKEYACALLDISPLAYAJMPLOOPINT7219:MOV50H,#0FHMOV51H,#00HMOVR0,#50HACALLSEND7219MOV50H,#0CHMOV51H,#01HMOVR0,#50HACALLSEND7219MOV50H,#0BHMOV51H,#05HMOVR0,#50HACALLSEND7219MOV50H,#0AHMOV51H,#09HMOVR0,#50HACALLSEND7219MOV50H,#09HMOV51H,#0FFHMOVR0,#50HACALLSEND7219 ACALL D1RETDISPLAY:MOV50H,#01HMOV51H,79HMOVR0,#50HACALLSEND7219MOV50H,#02HMOV51H,7AHMOVR0,#50HACALLSEND7219MOV50H,#03HMOV51H,7BHMOVR0,#50HACALLSEND7219MOV50H,#04HMOV51H,7CHMOVR0,#50HACALLSEND7219MOV50H,#05HMOV51H,7DHMOVR0,#50HACALLSEND7219MOV50H,#06HMOV51H,7EHMOVR0,#50HACALLSEND7219 ACALL D1RETSEND7219:CLRLOADMOVR4,#02HCLRCLOP1:MOVR1,#08HMOVA,R0LOP2:RLCAMOVDIN,CSETBCLKCLRCLKDJNZR1,LOP2INCR0DJNZR4,LOP1SETBLOADRET D1: MOV R6,#0FEH MOV R1,#08H MOV A,33H RL A RL A RL A MOV R4,A LP: MOV P3,#0FFH MOV A,R4 INC R4 MOV DPTR,#DTAB MOVC A,A+DPTR MOV P0,A MOV A,R6 MOV P3,A RL A MOV R6,A ACALL DEL DJNZ R1,LP RET DEL: MOV R7,#02H DL0:MOV R0,#0FFH DL6:DJNZ R0,DL6 DJNZ R7,DL0 RETKEY:JNBKEY1,KK1JBKEY1,$INCR3CJNER3,#05H,JMPKK3MOVR3,#00HJMPKK3:AJMPKK3KK1:JNBKEY2,KK2JBKEY2,$MOVA,R3RLAMOVDPTR,#KJMP1JMPA+DPTRKJMP1:AJMPDISCLKAJMPSINCAJMPMINCAJMPHINC AJMP DINCSINC:MOVA,SECONDADDA,#01HDAAMOVSECOND,ACJNEA,#60H,DISS1MOV30H,#01HDISS1:AJMPDISSMINC:MOVA,MINUTEADDA,#01HDAAMOVMINUTE,ACJNEA,#60H,DISM1MOVMINUTE,#00HDISM1:AJMPDISMHINC:MOVA,HOURADDA,#01HDAAMOVHOUR,ACJNEA,#24H,DISH1MOVHOUR,#00HDISH1:AJMPDISHDINC: MOV A,DAY ADD A,#01H MOV DAY,A CJNE A,#07H,DISD1 MOV DAY,#00H DISD1: AJMP DISDKK2:JNBKEY3,KK3JBKEY3,$MOVA,R3RLAMOVDPTR,#KJMP2JMPA+DPTRKJMP2:AJMPDISCLKAJMPSDECAJMPMDECAJMPHDEC AJMP DDECSDEC:MOVA,#9AHCLRCSUBBA,#01HADDA,SECONDDAAMOVSECOND,ACJNEA,#00H,DISS2MOVSECOND,#59HDISS2:AJMPDISSMDEC:MOVA,#9AHCLRCSUBBA,#01HADDA,MINUTEDAAMOVMINUTE,ACJNEA,#00H,DISM2MOVMINUTE,#59HDISM2:AJMPDISMHDEC:MOVA,#9AHCLRCSUBBA,#01HADDA,HOURDAAMOVHOUR,ACJNEA,#99H,DISH2MOVHOUR,#23HDISH2:AJMPDISHDDEC: MOV A,#9AH CLR C SUBB A,#01H ADD A,DAY DA A CJNE A,#99H,DISD2 MOV A,#06H DISD2:MOV DAY,A AJMP DISDKK3:MOVA,R3RLAMOVDPTR,#KJMP3JMPA+DPTRKJMP3:AJMPDISCLKAJMPDISSAJMPDISMAJMPDISH AJMP DISDDISCLK:MOVR0,#79HMOVR1,#HOURMOVR4,#03HCFLOOP:MOVA,R1SWAPAANLA,#0FHMOVR0,AINCR0MOVA,R1ANLA,#0FHMOVR0,AINCR0DECR1DJNZR4,CFLOOPSETBTR0RETDISS:CLRTR0MOVA,SECONDSWAPAANLA,#0FHMOV7DH,AMOVA,SECONDANLA,#0FHMOV7EH,AMOV79H,#0FHMOV7AH,#0FHMOV7BH,#0FHMOV7CH,#0FHAJMPKK5DISM:CLRTR0MOVA,MINUTESWAPAANLA,#0FHMOV7BH,AMOVA,MINUTEANL A,#0FHMOV7CH,AMOV79H,#0FHMOV7AH,#0FHMOV7DH,#0FHMOV7EH,#0FHAJMPKK5DISH:CLRTR0MOVA,HOURSWAPAANLA,#0FHMOV79H,AMOVA,HOURANLA,#0FHMOV7AH,AMOV7BH,#0FHMOV7CH,#0FHMOV7DH,#0FHMOV7EH,#0FH AJMP KK5 DISD: CLR TR0 MOV 79H,#0FH MOV 7AH,#0FH MOV7BH,#0FHMOV7CH,#0FHMOV7DH,#0FHMOV7EH,#0FHKK5:RETTIMER0:PUSHACCPUSHPSWMOVTH0,#0B1HMOVTL0,#0E0HDJNZR2,NEXTMOVR2,#50MOVA,SECONDADDA,#01HDAAMOVSECOND,ACJNEA,#60H,NEXTS1:MOVSECOND,#00HMOVA,MINUTEADDA,#01DAAMOVMINUTE,ACJNEA,#60H,NEXTS2:MOVMINUTE,#00HMOVA,HOURADDA,#01HDAAMOVHOUR,ACJNEA,#24H,NEXTS3:MOVHOUR,#00H MOV A,DAY ADD A,#01H DA A MOV DAY,A CJNE A,#07H,NEXT MOV DAY,#00HNEXT:POPPSWPOPACCRETI DTAB:DB 00H,08H,08H,08H,08H,08H,08H,00H DB 00H,04H,24H,24H,24H,24H,04H,00H DB 00H,02H,52H,52H,52H,52H,02H,00H DB 00H,0FFH,91H,0F1H,81H,0F1H,91H,0FFH DB 91H,91H,91H,0FFH,91H,91H,9FH,01H DB 20H,22H,24H,0A8H,60H,28H,24H,22H DB 00H,00H,0FFH,91H,91H,0FFH,00H,00HEND