摘 要



時鐘計時器要求用單片機及6位LED數(shù)碼管顯示時、分、秒，以24（小）時計時方式運行，能整點提醒（短蜂鳴，次數(shù)代表整點時間），使用按鍵開關(guān)可實現(xiàn)時、分調(diào)整，秒表/時鐘功能轉(zhuǎn)換，省電（關(guān)閉顯示）及定時設(shè)定提醒（蜂鳴器）等功能。本設(shè)計大體思路是：采用獨立式按鍵進(jìn)行時間調(diào)整，六位數(shù)碼管動態(tài)掃描的顯示方法。其中AT89C52是核心元件，同時采用數(shù)碼管LED動態(tài)顯示“時”，“分”，“秒”。與傳統(tǒng)機械表相比，時鐘計時器具有走時精確,顯示直觀等特點。它的計時周期為24小時，顯滿刻度為“23時59分59秒”，另外具有校時功能等特點。該系統(tǒng)同時具有硬件設(shè)計簡單、工作穩(wěn)定性高、價格低廉等優(yōu)點。

本設(shè)計中各功能的具體實現(xiàn)主要從硬件和軟件兩部分入手。硬件部分：對硬件電路進(jìn)行模塊化設(shè)計，其中時鐘接口電路為單片機及整個硬件電路的工作提供統(tǒng)一的工作頻率；復(fù)位電路保證了系統(tǒng)可以有固定的初始狀態(tài)；LED顯示電路在視覺上直觀地顯示軟硬件電路所達(dá)到的效果，用74LS244作為AT89C52的線驅(qū)動，用三極管9012作電源驅(qū)動輸出，以提供共陽LED數(shù)碼管的列掃描驅(qū)動電壓；蜂鳴器電路在對系統(tǒng)的操作時有聽覺上的明確提示；按鍵電路實現(xiàn)對時鐘計時器的各功能間切換；電源電路提供系統(tǒng)的工作電壓，并分別給出各部分設(shè)計電路圖。軟件部分：根據(jù)設(shè)計要求功能設(shè)計程序，包括主程序及顯示子程序；用于時間計時的定時器T0中斷服務(wù)程序；用于指示時間調(diào)整單元數(shù)字的閃亮或秒表計數(shù)的定時器T1中斷服務(wù)程序，調(diào)時功腀@絳潁氡砉δ@@絳潁種郵奔瀋瓚üδ@@絳虻雀髯映絳頡�



關(guān)鍵詞：AT89C52 LED顯示 74LS244















Abstract



Clock timer asked to use SCM and six LED digital display hours, minutes, seconds, to 24 (small), the run time, to remind the whole point (short beep, the number of representatives of the whole time), using key switches can be realized hour, minute adjustments, stopwatch / clock function of conversion, energy saving (turn off the display) and the time set reminders (buzzer) and so on. General idea of this design is: A stand-alone keypad for time adjustment, six digital tube display dynamic scan method. AT89C52 which is the core component, while the use of digital tube LED dynamic display "time", "sub", "seconds." Compared with the traditional mechanical watch, clock timer with walking precise, intuitive display, and so on. Its time period is 24 hours, was full scale is "23:59:59", another time with school functions and so on. The system also has the hardware design is simple, high stability, low cost and so on.

The design of the concrete realization of the function of major hardware and software from the start of two parts. Hardware components: modular design of hardware circuits, and clock circuit for the microcontroller interface, and the work of the entire hardware circuits to provide a unified operating frequency; reset circuit to ensure the system can have a fixed initial state; LED display circuit directly in the visual shows the effect achieved by software and hardware circuits, with a line drive 74LS244 as AT89C52 used for power-driven output transistor 9012 to provide a total of Yang LED digital tube series scan drive voltage; buzzer circuit in the system's operation is hearing The clear tips; button on the clock timer circuit to switch between the various functions; power supply circuit provides operating voltage is not fixed, and each part of the design circuit are given. Software part: According to the design function of the design process, including the main program and the display routines; for the time time the timer T0 interrupt service routine; used to indicate time to adjust cell count of the number of flashes or stopwatch timer T1 interrupt service routine , transfer function of process time, stopwatch function procedures, alarm time setting function procedures and other routines.



Keywords: AT89C52 LED display 74LS244









目 錄



摘 要 i

Abstract ii

第一章 緒 論 1

第二章 設(shè)計方案的確定 2

第三章 系統(tǒng)硬件電路的設(shè)計 4

第一節(jié) 控制電路的設(shè)計 5

一、主芯片選定 5

二、主芯片時鐘電路的設(shè)計 12

三、復(fù)位電路的設(shè)計 13

第二節(jié) 顯示電路設(shè)計 16

一、顯示器的選擇 16

二、LED顯示結(jié)構(gòu)與原理 16

三、數(shù)碼管的驅(qū)動方式 17

四、驅(qū)動芯片選用 18

五、電源驅(qū)動輸出器件 19

第三節(jié) 蜂鳴器電路的設(shè)計 20

第四節(jié) 按鍵電路設(shè)計 20

第五節(jié) 電源電路設(shè)計 21

第四章 控制系統(tǒng)的軟件設(shè)計 23

第一節(jié) 主程序 23

第二節(jié) 顯示子程序 23

第三節(jié) 定時器T0中斷服務(wù)程序 24

第四節(jié) 定時器T1中斷服務(wù)程序 25

第五節(jié) 調(diào)時功腀@絳� 26

第六節(jié) 秒表功腀@絳� 26

第七節(jié) 鬧鐘時間設(shè)定功腀@絳� 26

第五章 控制程序的編制和調(diào)試 27

第一節(jié) 硬件調(diào)試 27

第二節(jié) 軟件調(diào)試 27

第三節(jié) 軟硬件聯(lián)調(diào) 27

第四節(jié) 性能分析 27

總結(jié)和展望 29

參考文獻(xiàn) 30

附 錄Ⅰ 時鐘計時器的硬件電路圖 31

附 錄Ⅱ 單片機匯編源程序清單 32

外文資料 54

中文譯文 61

致謝語 67