1概述.....................1.1研究背景...................................1.2設(shè)計思想及基本功能.........................2總體方案設(shè)計..................................................22.1方案選取.................................................22.2系統(tǒng)框圖.................................................32.3總體方案設(shè)計.............................................33硬件電路設(shè)計............................................3.2晶振電路.................................................53.3復(fù)位電路.................................................63.4鍵盤電路.................................................73.5顯示電路.................................................74系統(tǒng)軟件設(shè)計........................................4.1主程序軟件設(shè)計..........................................124.2鍵盤程序設(shè)計............................................134.3定時程序設(shè)計............................................134.4報警程序設(shè)計............................................155Proteus仿真........................................6總結(jié)............................................參考文獻(xiàn)................路燈的短暫倒計時，當(dāng)你玩游戲時游戲時間結(jié)束的倒計時?..，而這些不同功量輕、耗電省、可靠性高、價格低等優(yōu)點，開始不斷發(fā)展，AT89C51單片機(jī)是該倒計時牌采用廉價可靠的LED數(shù)碼管顯示，能夠根據(jù)使用合實際情況設(shè)置不同時間長度的倒計時，在設(shè)定的倒計啟動報警裝置，并且顯示恢復(fù)到初始狀態(tài)。利用專業(yè)的單片機(jī)仿真軟件離上對視覺上的觀察有一定的困難?；谝詧D2.1a方案（二）LCD1602液晶顯示器圖2.1b方案（二）12864液晶顯示器圖2.2方案（三）LED數(shù)碼管實物圖圖2.6倒計時牌結(jié)構(gòu)框圖圖3.2單片機(jī)晶振電路圖然后繼續(xù)從0000H單元開始執(zhí)行程序。在復(fù)位電路中提供機(jī)輸入指令，其中主要包括設(shè)定時間功能，是以及定時器的啟動。K2鍵，其作用主要是用于時間調(diào)整；復(fù)位鍵主要應(yīng)圖3.6LED數(shù)碼管顯示原理圖3.8MAX7219的時序圖?INIT:MOVA,#0FBHMOVB,#07HLCALLSENDMOVA,BLCALLSENDSETBP2.1MOVA,#0F9HMOVB,#00HLCALLSENDMOVA,BLCALLSENDSETBP2.1MOVA,#0FAHMOVB,#0CHLCALLSENDMOVA,BLCALLSENDSETBP2.1LCALLSENDMOVA,#0FCHMOVB,#01HLCALLSENDMOVA,BLCALLSENDSETBP2.1SEND:CLRP2.1MOVR4,#08HLP1:RLCAMOVP2.0,CCLRP2.2NOPNOPNOPNOPNOPSETBP2.2DJNZR4,LP1RET圖圖3.10蜂鳴器的驅(qū)動電路體的程序代碼見附錄。系統(tǒng)軟件設(shè)計主要包括單片機(jī)初始化程序、顯示子程圖圖4.1主程序流程圖此時邏輯電平是不穩(wěn)的，如果得不到正確處理的錯誤執(zhí)行。但本次設(shè)計中鍵盤的主要是利用圖4.2鍵盤程序流程圖圖圖4.3定時程序流程圖需求選擇等待下一次倒計時開始或倒計時結(jié)束。如下圖4.4給出圖4.4報警程序流程圖圖圖5.2倒計時時間設(shè)置圖5.3a倒計時時間顯示1圖5.3b倒計時時間顯示2圖5.4倒計時結(jié)束仿真圖進(jìn)一步的鞏固了單片機(jī)基礎(chǔ)知識。剛拿到題目的學(xué)習(xí)單片機(jī)的時候做過類似的題目，不過那時做小工程基礎(chǔ)，但在本次倒計時牌設(shè)計中還是遇到液晶顯示屏，但后來發(fā)現(xiàn)LCD液晶顯示屏顯示的字體太小、顯示功能其次，是在硬件電路的設(shè)計中，原本采用的是LED數(shù)碼管的靜態(tài)顯示，但在實際搭建電路的時候，軟件的圖紙根本放不下8位數(shù)碼管，即便使用總線、網(wǎng)絡(luò)標(biāo)號電路也略顯復(fù)雜。因此，我最終決定的一個驅(qū)動芯片-----MAX7219。MAX7219雖然功能實現(xiàn)上相對較難，但它極大悉駕輕就熟的C語言，還是對硬件電路理解比較深的匯編?LEDBITP1.7BUZZERBITP1.0LJMPMAINORG0003HLJMPINT_0ORG000BHORG0013HLJMPINT_1ORG0100HMAIN:LCALLINITCLRP1.0MOV30H,#00HMOV31H,#00HMOV32H,#00HMOV33H,#00HMOVR1,#00HMOVR2,#00HMOVR3,#20MOVTMOD,#01HMOVTH0,#3CHMOVTL0,#0B0HSETBEX0SETBET0SETBEX1LCALLZMZHINIT:MOVA,#0FBHMOVB,#07HLCALLSENDMOVA,BLCALLSENDSETBP2.1MOVA,#0F9HMOVB,#00HLCALLSENDMOVA,BLCALLSENDSETBP2.1MOVA,#0FAHMOVB,#0CHLCALLSENDMOVA,BLCALLSENDSETBP2.1LCALLSENDMOVA,#0FCHMOVB,#01HLCALLSENDMOVA,BLCALLSENDSETBP2.1RETCAIFEN:MOVB,#10DIVABMOVCA,@A+DPTRRETZMZH:MOVDPTR,#TABMOVA,33HACALLCAIFENMOV46H,AMOVA,BMOVCA,@A+DPTRMOV47H,AMOVA,32HACALLCAIFENMOV44H,AMOVA,BMOVCA,@A+DPTRMOV45H,AMOVA,31HACALLCAIFENMOV42H,AMOVA,BMOVCA,@A+DPTRMOV43H,AMOVA,30HACALLCAIFENMOV40H,AMOVA,BMOVCA,@A+DPTRMOV41H,ADISPLAY:MOVA,#00HMOV48H,#08HMOV49H,#08HMOVR0,#47HLP3:MOVA,48HLCALLSENDMOVA,@R0LCALLSENDSETBP2.1LCALLDELAYDEC48HDECR0DJNZ49H,LP3RETSEND:CLRP2.1MOVR4,#08HLP1:RLCAMOVP2.0,CCLRP2.2NOPNOPNOPNOPNOPSETBP2.2DJNZR4,LP1RETLCALLBZDELAYCLRLEDLCALLBZDELAYRETINT_0:PUSHPSWCJNER1,#05H,RE1SETBTR0MOVR1,#00HMOVR2,#0FFHRETIIT_0:MOVTH0,#3CHMOVTL0,#0B0HACALLDJSHIRETIINT_1:PUSHPSWPUSHACCCJNER1,#00H,TIMCHRETURN:POPACCPOPPSWRETITIMCH:CJNER1,#01H,MIAOMOVA,33HLCALLZMZHCJNEA,#60,RETURNMOV33H,#00HSJMPRETURNMIAO:CJNER1,#02H,FENMOVA,32HLCALLZMZHCJNEA,#60,RETURNMOV32H,#00HRETFEN:CJNER1,#03H,SHIMOVA,31HLCALLZMZHCJNEA,#24,RETURNMOV31H,#00HSJMPRETURNSHI:CJNER1,#04,RETURNMOVA,30HLCALLZMZHCJNEA,#100,RETURNMOV30H,#00HRETDELAY:MOV34H,#14HLP2:MOV35H,#8AHDJNZ35H,$DJNZ34H,LP2RETDJSHI:DJNZR3,LP4MOVR3,#20LCALLZMZHMOVA,33HCJNEA,#0FFH,LP4MOV33H,#3BHLCALLZMZHMOVA,32HCJNEA,#0FFH,LP4MOV32H,#3BHLCALLZMZHMOVA,31HCJNEA,#0FFH,LP4MOV31H,#17HLCALLZMZHMOVA,30HCJNEA,#0FFH,LP4CLRTR0MOV30H,#00HLCALLZMZHMOV31H,#00HLCALLZMZHMOV32H,#00HLCALLZMZHMOV33H,#00HLCALLZMZHLCALLFMLP4:RETBZDELAY:MOV36H,#0FAHL1:MOV37H,#0FAHL2:DJNZ37H,L2DJNZ36H,L1RETTAB:DB7EH,30H,6DH,79H,33H,5BH,5FH,70H,7FH,7BHEND:1001000012012FC2907530007531007532007533C1:100110000079007A0073C758AB072:10012000D2AFD2A8D288D2A9D2AAD28A120175742B:10013000FB75F0071201C3E5F01201C3D2A174F9F7:1001400075F0001201C3E5F01201C3D2A174FA7573:10015000F00C1201C3E5F01201C3D2A11201C37465:10016000FC75F0011201C3E5F01201C3D2A12275A2:10017000F00A8493229002B8E533316FF546E5F03A:1001800093F547E532316FF544E5F093F545E531F8:10019000316FF542E5F093F543E530316FF540E519:1001A000F093F54174007548087549087847E548AB:1001B0001201C3E61201C3D2A112024B154818D591:1001C00049EC22C2A17C083392A0C2A20000000028:1001D00000D2A2DCF222D2901202ABC2971202AB82:1001E00022C0D009B90506D28C79007AFFD0D0326E:1001F000758C3C758AB0515832C0D0C0E0B900054A:10020000D0E0D0D032B9010F0533E533120175B417:100210003CEE75330080E9B9020E0532E532120179:1002200075B43CDC75320022B9030F0531E531129B:100230000175B418CB75310080C6B904C30530E52B:1002400030120175B464B9753000227534147535F7:10025000