【正文】 作。 接口工作時序 有關(guān) AT24C 的啟動條件、停止條件、應(yīng)答信號、非應(yīng)答信號、數(shù)據(jù) 的傳輸、數(shù)據(jù)的接收等時序 由于 AT24C 是標(biāo)準(zhǔn)的器件詳見部分。 在訪問 I2C 器件時 ，緊跟在器件地址后要訪問存儲器單元地址， 對于 AT24C01/02，單個字節(jié)的存儲器地址已經(jīng)足夠表示想要訪問的任何一個存儲器空間。 ● WP，寫保護引腳。對于不具備 I2C 總線硬件接口的有些單片機來說為了檢測起始和終 止信號 ，必須保證在每個時鐘周期內(nèi)對數(shù)據(jù)線 SDA 采樣兩次。在傳輸數(shù)據(jù)開始前，主控器件應(yīng)發(fā)送起始位，通知從器件做好接收準(zhǔn)備，在傳輸數(shù)據(jù)結(jié)束時，主控器件應(yīng)發(fā)送停止位，通知從器件停止接收。兩線 ―― 串行數(shù)據(jù)（ SDA）和串行時鐘 （ SCL）線在連接到總線的器件間傳遞信息。 無錫科技職業(yè)學(xué)院畢業(yè)設(shè)計（論文） 基于單片機的多功能電表設(shè)計 9 LED 數(shù)碼管 led 數(shù)碼管（ LED Segment Displays）是由多個 發(fā)光二極管 封裝在一起組成“8”字型的器件，引線已在內(nèi)部連 接完成，只需引出它們的各個筆劃，公共電極。 是 單 片機的核心 單 元，通常由算 術(shù)邏輯運 算部件 ALU 和控制部件構(gòu)成。 主復(fù)位 ( MR________) 輸入端上的一個低電平將使其它所有輸入端都無效 ，同時非同步地清除寄存器，強制所有的輸出為低電平。 無錫科技職業(yè)學(xué)院畢業(yè)設(shè)計（論文） 基于單片機的多功能電表設(shè)計 6 4， AD7755 是對 ESD(靜電放電 )敏感的器件 ,在人體和測試設(shè)備上的靜電荷很容易累計高達 4000V,并 在沒有察覺的情況下被放電 ,雖然有 ESD 保護電路 ,但高能量的放電仍能造成器件的永久性損壞 ,因此應(yīng)該采取靜電放電預(yù)防措。在 AVDD 上升到 4V 之 前 ,ADE7755 一直保持在復(fù)位狀態(tài)。兩通道之間的增益校準(zhǔn)在器件外部進行調(diào)整。電流通道中的 HPF 濾掉電流信號中的直流分量 從而消除了由于電壓或電流失調(diào)所造成的有功功率計算上的誤 差。引腳 CF 以較高頻率形式輸出有功功率瞬時值 ，用于校驗或與微控制器接口。本課題研究的功能電能表能夠讓居民可以方便的完成電量繳費，用戶對用電量更加清晰明了。電能表又俗稱電度表或千瓦時表。電能可以轉(zhuǎn)換成各種能量。 AT24C16 通過 I2C 總線和單片機連接，單片機將居民的用電量實時寫入 AT24C16 AT24C16 仍能保存數(shù)據(jù)，再次上RS485 總線與抄表集中器相連，接收抄表集中器下達的抄表，或預(yù)付費、清零等命令。 74HC164 串入并出 8位移位寄存器和 LED 顯示器能夠?qū)崟r循環(huán)顯示 8戶居民的用電量。 關(guān)鍵詞： 功率測量 、 AT89C51 單片機 、 ADE775 LED 顯示 無錫科技職業(yè)學(xué)院畢業(yè)設(shè)計（論文） 基于單片機的多功能電表設(shè)計 ii Electricity automatic controller Abstract： Along with the material life of the rich, many people move into the city, as the 1 part of your life. We use FM3307\/8 microcontroller as the core of the 8 households electricity consumption measurement, let everyone know what how to use single chip microputer to measure the amount of power. 8 pulse output electric energy metering chip AD7755 to the residents of the electricity into a certain number of pulses. 74HC164 series input and output 8 bit shift register and LED monitor can display realtime circulation of 8 households of electricity. AT24C16 through the I2C bus and the singlechip is connected with the MCU will residents consumption realtime write AT24C16 when power AT24C16 can still save the data once again after power on the MCU will save the data read in order to achieve powerdown protection. Electric energy meter through the RS485 bus and the concentrator is connected to receive the meter reading concentrator reading or prepaid, reset mand. Meter reading concentrator has GPRS munication module MC55 to realize data ， the upload or mand through GPRS munication work and center puter connection issued. When working, voltage through the resistor divider, a current through the current transformer in the sampling resistance after sampling, into the special power chip for processing, and converted into digital signal is sent to the CPU calculation. Due to the adoption of a special power chip, the voltage and current sampling resolution is improved greatly, and have enough time to more accurate measurement of electric energy metering, so that the electric power meter accuracy has been significantly improved. CPU is used for timesharing charging and processing a variety of input and output data, the special power chip via the serial interface to read data, and according to the preset time plete the timesharing active electric energy metering and demand maximum measurement function, according to the need to display the data munication transmission, infrared or RS485 interface, monitoring and operation parameters store all kinds of data, records. Let the puter according to the different price of electricity time division point of the realization of multirate 無錫科技職業(yè)學(xué)院畢業(yè)設(shè)計（論文） 基于單片機的多功能電表設(shè)計 iii function table. Computer users will advance purchase power into electric energy meter when in power to 0 of the control port， P4 action to cut off power supply. Key Words: power measurement、 AT89C51 MCU、 ADE775 LED display 無錫科技職業(yè)學(xué)院畢業(yè)設(shè)計（論文） 基于單片機的多功能電表設(shè)計 iv 目錄 前言 ................................................................................................................................ 1 第一章 論述 ................................................................................................................ 2 課題的 背景及應(yīng)用范圍 ...................................................................................... 2 課題的目的 ..................................................................................