I. Topics and Requirements of Graduation Design (II) 1. Design requirements for the Y-△ start of motor controlled by single chip microcomputer: 1) The controller is a single chip microcomputer and the motor is a three-phase asynchronous motor; 2) The startup time is 3 seconds; 3) Set the motor Y-△ to run and stop by pressing the key. 2. Design requirements of adjustable DC regulated power supply based on single chip microcomputer control: 1) The controller is single chip microcomputer, the voltage output range is 0- 10V, and the voltage accuracy is 0.1v; ; 2) display the voltage value through the digital tube; 3) Set the voltage value by pressing the key. Second, the main software (and functions) used in graduation design The main software (and functions) used in graduation design: Keil 5 1 (source code compilation), Proteus (circuit simulation), AutoCAD (drawing), Visio (drawing flow chart), Protel 99SE (schematic circuit design, PCB board production) Third, the graduation design requirements of single chip microcomputer are 65438. 2. Learn to use Proteus circuit simulation software to simulate the designed hardware circuit. 3. When writing graduation thesis, learn to draw program flow chart and circuit schematic diagram with software such as Word, AutoCAD, Visio and Protel 99SE. Friends, take 5 1 single chip microcomputer as an example. 5 1 Now it is all online debugging of simulators, and each company's simulators will have their own programming software, which is not much different from keil. The steps are as follows: 1. Create a new program. 2. Connect the emulator or writer. You can set up an emulator or writer at this step, depending on their descriptions. 3. Compile the program. This step will automatically check whether your program is correct. If you are wrong, you can't go to the next step. If you use an emulator, you can run it directly after this step is compiled successfully. 4. If you use writer, the software and debugging methods will be somewhat different, but they are generally the same, and some debugging tools are also described in detail. The measurement technology of chemical parameters involves a wide range, especially when the micro-voltage, micro-current, high voltage and the intensity of the signal to be measured are very different, it is technically difficult to ensure the measurement accuracy of weak signals and give consideration to the measurement range of strong signals. When traditional low-cost instruments measure voltage and resistance, they use the method of manually selecting gear to change the range. In use, when you forget to shift gears, the measuring accuracy of the instrument will be reduced or damaged. Modern electronic measurement requires higher accuracy and intelligence of the system. On the premise of ensuring the measurement accuracy, full-range automatic range conversion voltmeter and resistance meter are widely used without manual range conversion. This paper introduces an intelligent multimeter based on AT89S52 single chip microcomputer. The instrument completes the measurement of DC voltage, resistance and DC current under the control of single chip microcomputer. In the current measurement part, a simple I/V conversion circuit is used to complete the test. In the voltage measurement part, analog switch CD405 1 and operational amplifier OP07 are used to form a program-controlled amplifier to realize automatic range conversion. The resistance measurement part also combines the analog switch CD405 1 and the operational amplifier OP07 to complete the automatic range conversion under the control of the single chip microcomputer. The final measured signals of current, voltage and resistance are collected by 12-bit A/D converter TLC2543 under the control of single chip microcomputer, and the collected signals are displayed by LCD( 12864) after being processed by single chip microcomputer. The measurement results can also be saved by CPU memory with serial EEPROM and monitor's X25045. Key words: TLC2543 automatic range conversion program-controlled gain amplifier voltage, resistance and current directory abstract 1 abstract 2 Chapter 1 Introduction 5 1. 1 overview 5 1. 2 Intelligent Instruments/Overview of Instrument Development at Home and Abroad 5 1. 3 The purpose and significance of the study 6 Chapter 2 Introduction to the system structure and function 8 2. 1 System function and performance index 8 2. 1 instrument function 8 2. 1.2 performance index 8 2. 1.3 local characteristics 8 2.65438.5438+0. 4 system description 9 2. 2 Overview of the working principle of the system 9 Chapter III Scheme Design and Demonstration 1 13. 1 Design and Demonstration of Scope Selection 1 1