此文档是毕业设计外文翻译成品（ 含英文原文+中文翻译），无需调整复杂的格式！下载之后直接可用，方便快捷！本文价格不贵,也就几十块钱！一辈子也就一次的事！外文标题：Design of Liquid Crystal Digital Voltmeter Based on Single Chip Microcomputer外文作者：Wang Hui-feng ,Liu Xiao-hua文献出处:Consumer Electronics, Communications and Networks (CECNet), 2018 (如觉得年份太老，可改为近2年，毕竟很多毕业生都这样做)英文1847单词，11902字符(字符就是印刷符)，中文2879汉字。Design of Liquid Crystal Digital Voltmeter Based on Single Chip MicrocomputerAbstract: The design is based on Atmel51 microcontroller development platform and automatic control based on the principle of a digital voltage meter system The system uses Atmel89C52 microcontroller as the control core, ADC0832 for the sampled data system, The use of a zener diode for over voltage protection, and through the realization of analog switch achieves the input range automatic conversion, character liquid crystal display shows the measured voltage.Key words: Digital voltmeter;Atmel89C52; A/D converter;I. THE OVERALL SYSTEM DESIGN SCHEMEThis system realize the function mainly through thehardware design and software programming. First, according to the design requirements to produce complete the design of circuit diagram. The hardware circuit uses ATMELs AT89C52 as the main processor, the system is mainly composed of signal acquisition, A/D conversion, data processing and output, drive and display modules. Second, according to the circuit diagram of program control chip, the program design use assembly language programming, the compilation and simulation using Keil software. The SCM control A/D converter analog to digital conversion, and display the corresponding voltage value on the LED.Figure 1. System block diagramThe measured DC voltage is collected and quantified by A/D conversion unit, then the results of the A/D conversion are scale transformatied by microcontroller to get the value of measured voltage.SCM average logarithmicly over the results of all transformation, then output the average value through the SPI serial data interface to the display driving unit, the unit complete the decoding, and drive the digital display.II.THE HARDWARE DESIGN AND THE CIRCUIT CHARTA.Power Supply CircuitThree terminal regulator composed by some triode and resistor is a kind of integrated circuit element.when analyzing circuit, we can think it is a element adjusting the resistance automatically.when load current is large, resistance of three terminal regulator automatically becomes small, and when the load current is smaller, the resistance of the three terminal regulator change automatically, so we can maintain the output voltage constant.Wanting to output the voltage of 5V,we so the select 7805. The letter in front of 7805 may be different due to manufacturers. the maximum output current of LM7805 is 1A, there is current limit short circuit protection in it,so a short period of time, such as a few seconds, short circuit of output to ground (2 feet) will not make 7805 burned out. Three terminal regulator followed by a 104 capacitor, the capacitor has the effect of wave filtering and damping.Figure 2. Ower Supply CircuitB.The A/D Conversion ModuleDue to the type of analog conversion circuit, based on the precision, the conversion speed and stability, this design uses the ADC0832 conversion chip. The ADC0832 connected whith Single chip microcomputer through 3 wire interface is a serial interface of 8 bit A/D converter produced by National Semiconductor Corporation Ns. Bing of low power consumption, high cost performance, the ADC0832 is suitable to be used in intelligent instruments in the pocket. The ADC0832 is 8 bits resolution A/D conversion chip, the highest resolution can reach 256 level, can meet the general requirements for conversion of analog quantity. Double data output of the chip can be used as data verification, to reduce the error,besides,fast switching speed and stronger stability, independent of the chip make multiple devices connection and processing control becomes more convenient. Channel function choice can be achieved easily through the DI data input, can easily achieve. Its main features are as follows:1.8 bit resolution, successive approximation, the reference voltage is 5V;2.A single 5V power supply;3.Analog signal input voltage range of 0 5V;4.Input and output level with TTL and CMOS compatibility;5.In the clock frequency of 250Khz, the conversion time is 32us;6.With 2 alternative analog input channel;7.Low power consumption (15MW);8.Support SPI.C.The Interface ModuleAT89C52 MCU as the control unit system, convert analog to the amount of data into the single chip microcontroller through the A/D converter, and then sent to the display. In This scheme, all kinds of functions is easy to realize, low cost, low power consumption, stable display can set the power saving mode by software. The idle mode, the CPU suspended the work, while the RAM timing / counter, serial port, and interrupt system can continue to w