【正文】 電阻的緣故。 P2口： P2口為一個(gè)內(nèi)部上拉電阻的 8位雙向 I/O 口， P2口驅(qū)動(dòng) 4個(gè) TTL 門電流，當(dāng) P2口被寫 “ 1” 時(shí)，其管腳內(nèi)部上拉電阻被拉高，且作為輸入口。 GND：接地。同時(shí)該芯片還具有 PDIP、 TQFP 和 PLCC 等三種封裝形式，以適應(yīng)不同產(chǎn)品的需求。 10V 時(shí)，可獲得滿量程四象限的可乘操作。 XFER 與 2WR 配合使用，構(gòu)成第二級(jí)鎖 存。 (2) CS ：片選信號(hào)，低電平有效。其邏輯表達(dá)式為 ? ? 11 WRCSILELE ??? 由此可知，當(dāng) 1?ILE ， 01??WRCS 時(shí)， ?? 11?LE ，允許數(shù)據(jù)輸入，而當(dāng) 11?WR 時(shí)， ?? 01?LE ，數(shù)據(jù)被鎖存。 DAC0832 是單電源供電，在 +5~+15V 范圍內(nèi)均可正常工作，基準(zhǔn)電壓的范圍為177。韓國(guó)制訂了“ GaN 半導(dǎo)體開發(fā)計(jì)劃 ”[3]。目前我國(guó)對(duì) LED 路燈尚未出臺(tái)國(guó)家標(biāo)準(zhǔn)，這也在一定程度上阻礙 了 LED 路燈技術(shù)的發(fā)展和 LED路燈的推廣應(yīng)用 [2]。而 LED 照明作為一種革命性的節(jié)能照明技術(shù)， 低碳技術(shù) 正在飛速發(fā)展。 在全球能源 短缺、環(huán)保要求不斷提高的背景下，世界各國(guó)均大力發(fā)展綠色節(jié)能照明和低碳經(jīng)濟(jì)。五邑大學(xué)本科畢業(yè)設(shè)計(jì) I 摘 要 本設(shè)計(jì)完成了以 AT89S52 單片機(jī)和 DAC0832 數(shù)模轉(zhuǎn)換芯片為核心的 LED 路燈低功耗智能控制裝置。 關(guān)鍵詞 恒流驅(qū)動(dòng)； 電路 故障；液晶顯示； 保護(hù) 電路 ； 聲光控制 五邑大學(xué)本科畢業(yè)設(shè)計(jì) II Abstract The core LED street lamp low power consumption intelligent control device is pleted with AT89S52 SCM and DAC0832 analogtodigital conversion chips. The design is posed of power supply module, LED by constant current drive power supply module and singlechip microputer control module, street lamp signal detection module, LCD display module, sound and light alarm module, key module, temperature sensing module. SCM is according to sound and light sensor to curb status of detection and clock chip DS12C887 setup time to control the D/A conversion chip and LED constant current driver together to acplish the street lamp brightness LED the automatic adjustment,through the realization of the control realy LED lamp switch,and of the diode protection circuit. Turn on the light, turn off the lights and instant time to get the time dynamic street light appeared circuit fault, the design also can appear sound and light alarm. The control system of the position, the hardware and software of the relate design and work principle are introduced in the paper. And the method of how to use AT89S52 devices control chip realize DAC0832 LED drive circuit is emphasized. Key words Constant Current Drive Circuit Fault LCD Display The Protection Circuit Sound And Light Control 五邑大學(xué)本科畢業(yè)設(shè)計(jì) III 目 錄 摘要 .................................................................................................................................................. I Abstract ...........................................................................................................................................II 第 1 章 緒論 ............................................................................................................................... 1 課題來源及研究的目的和意義 ................................................................................... 1 國(guó)內(nèi)外在該方向的研究現(xiàn)狀及分析 ........................................................................... 1 本課題研究的主要內(nèi)容 ............................................................................................... 2 第 2 章 本設(shè)計(jì)用到的主要元器件 ........................................................................................... 3 數(shù)模轉(zhuǎn) 換芯片 ............................................................................................................... 3 52 單片機(jī) ...................................................................................................................... 4 AT89S52 的特 點(diǎn) ................................................................................................. 4 管腳說明 ............................................................................................................. 5 駐極體話筒 ................................................................................................................... 6 光敏電阻 ....................................................................................................................... 7 電磁繼電器 ................................................................................................................... 7 時(shí)鐘芯片 ....................................................................................................................... 7 本章小結(jié) ....................................................................................................................... 9 第 3 章 硬件電路的原理與設(shè)計(jì) ............................................................................................. 10 概述 ............................................................................................................................. 10 系統(tǒng)設(shè)計(jì)原理框圖 ..................................................................................................... 10 供電模塊 ..................................................................................................................... 11 單片機(jī)控制模塊 ......................................................................................................... 11 LED 恒流驅(qū)動(dòng)電源模塊 ............................................................................................. 12 路燈信號(hào)檢測(cè)模塊 ..................................................................................................... 13 時(shí)鐘驅(qū)動(dòng)電路 ................................................................................................... 13 聲控電路 ........................................................................................................... 14 環(huán)境光線及故障檢測(cè)電路 ............................................................................... 14 聲光報(bào)警模塊 ............................................................................................................. 15 按鍵模塊 ..................................................................................................................... 15 顯示模塊 ..................................................................................................................... 16 本章小結(jié) ...................................................................................................................... 16 第 4 章 軟 件設(shè)計(jì) ..................................................................................................................... 17 概述 ...........................................................