The content and significance of graduation project
Graduation design content:
1. Be familiar with the design method of single chip microcomputer system, and complete the circuit and program design independently.
2. Use PROTEUS to debug and simulate the system.
3. Design, manufacture and debugging of hardware system.
4. Complete relevant software documentation.
Technical documents to be completed for graduation design:
1.3000 words graduation project opening report, 2000 words English reference translated into Chinese.
2. Graduation design thesis (15000 words or more).
3. Provide design schematic diagram and corresponding program.
The significance of graduation project:
With the development of the times and the acceleration of modernization, the demand for road lighting and road lighting engineering is increasing, the contradiction between supply and demand of energy is becoming more and more prominent, and the requirements for energy saving and green lighting are becoming more and more urgent and higher. Nowadays, the traditional methods of manual control and clock control of lighting system can no longer meet the requirements. How to make full use of high-tech means to solve the above contradictions has become a new and urgent topic in the field of lighting control. Street lamp lighting is an indispensable public facility in daily life. The electricity consumption of street lamps accounts for about 15% of the total electricity consumption, and all parts of the country are facing various problems caused by power shortage. In the face of power shortage, street lamp inspection is a job that requires a lot of manpower from the state. Various temporary emergency power-saving measures are widely used: turning off lights at night intervals, adjusting the switching time of street lamps, turning off landscape lighting on power shortage days, etc. These measures may be put on hold after the peak electricity consumption, and everything will start again when the peak electricity consumption comes next year. This energy-saving measure not only relieves power shortage, but also brings waste of resources and negative impact on people's daily life. The best and effective way to alleviate the shortage of electricity consumption is to implement intelligent management of electricity consumption, reduce waste and make the best use of it! Advanced street lamp monitoring system can be used to uniformly turn on and off street lamps, monitor and manage night lighting system and street lamps in real time, ensure efficient and stable operation all day, control unnecessary "all-night lighting" and effectively save power consumption. For school public lighting system, adopting intelligent management system is a scientific solution to realize energy saving, reduce resource waste, meet people's living needs and show modern campus.
At present, a small number of campuses refer to the energy-saving measures of street lamps, and turn down the brightness of the lights in the latter half of the night, or use the way of lighting at equal intervals to save electricity, but this method brings the problem that the street lamps are too bright or too dark:
1. Inverse control
The way of switching lights is relatively backward: at present, street lamp control still stays in manual, light control and clock control modes. Affected by seasons, weather and human factors, the level of automatic management is low, and it is often on and off, which is easy to cause great energy waste and increase financial burden.
2. Inconvenient control
Insufficient control ability, unable to remotely modify the on-off time, unable to timely correct and modify the on-off time according to the actual situation (sudden weather changes, major events, festivals).
3. Unknown lighting conditions
Without street lamp monitoring, the existing lighting facilities management mainly adopts manual inspection mode, which not only has a large workload, but also wastes manpower, material resources and financial resources. The fault basis mainly comes from the lack of initiative, timeliness and reliability of patrol personnel's reports and citizens' complaints, and the inability to monitor the running status of street lamps in the city in real time, accurately and comprehensively, and the lack of effective fault early warning mechanism.
4. It didn't work well in the first half of the night.
Because it uses the normal brightness of more than 6 hours in the first half of the night, it will waste power resources when there are no pedestrians and vehicles on the campus road. Except for the peak hours from 6 pm to 9 pm, the flow of people and vehicles is relatively small, so we think that campus lighting has greater energy-saving potential.
Based on the analysis of the current energy-saving situation, an efficient and intelligent energy-saving street lamp is designed. The street lamp controller should be equipped with both light control and time control modules, which obey the photometric control first and then the time control, so as to meet the requirements of turning on and off street lamps at a certain luminosity and at a specific time. At the same time, we think that street lamps should be improved into infrared induction street lamps. Street lamps are divided into energy-saving state and standard state according to the height of campus traffic peak hours. During the peak hours of people and vehicles, such as the early and late off hours of 18-2 1, the street lamp should maintain a continuous standard brightness, but in the middle of the night, the street lamp will turn into an energy-saving state, and it will only light up when people and vehicles pass by through infrared induction. Using infrared sensing, compared with voice control, the sensing accuracy is higher, and some noises are avoided to make the lights flicker ineffectively. All street lamps are connected to the single chip microcomputer, which communicates with the computer, and the computer controls the working state of the street lamps. Automatic control mode and manual control mode can be set. The automatic control mode can control the working mode of street lamps according to the law of solar activity and the actual situation. When night falls, or when the light is already dark, it can be turned on automatically, although it has not yet reached the set time. During peak hours, it should be fully lit continuously; After the peak period, enter infrared sensing to realize intelligent energy-saving control. Manual control mode can set the switching time and opening ratio of street lamps at any time or control the opening and closing of street lamps separately. In addition, through the working state of the street lamp, the damage of the street lamp can be alarmed in real time, and the specific position can be displayed to remind the maintenance personnel to maintain it in time. The central controller has a clock chip with EEPROM, which can save the working parameters of the single chip microcomputer. Even if there is a communication error, the street lamp can work according to the final procedure.
Literature review
I. Design scheme
In this design, STC89C52 single chip microcomputer is selected as the core component of the system to realize the control and processing functions of the system. The functions of each module are as follows: (1) infrared module: detect whether there are pedestrians at night. (2) Display module 12864: display the corresponding time and date information. (3) Clock module: switch the time manually and set the startup time by yourself. (4) The photosensitive resistance sensor module is used to detect the intensity of ambient light, and if the intensity is lower than the standard value, the street lamp is turned on.
Second, the hardware circuit design
1. main controller STC89C52
STC89C52 is a low-power and high-performance CMOS8-bit microcontroller produced by STC company, with built-in 8K in-system programmable flash memory. STC89C52 adopts the classic MCS-5 1 kernel, but many improvements have been made to make the chip have functions that the traditional 5 1 single chip microcomputer does not have. On a single chip, STC89C52 adopts intelligent 8-bit CPU and in-system programmable Flash, which provides highly flexible and efficient solutions for many embedded control application systems.
STC89C52 has the following standard functions: 8 kilobytes of Flash, 5 12 bytes of RAM, 32-bit I/O port line, watchdog timer, built-in 4KBEEPROM, MAX8 10 reset circuit, 3 16-bit timers/counters and 4 external interrupts. And a 7-vector 4-level interrupt structure (compatible with the traditional 565438). In addition, STC89C52 can be reduced to 0Hz static logic operation, supporting two kinds of idle mode, when CPU stops working, allowing RAM, timer/counter, serial port and interrupt to continue working. In the power-off protection mode, the RAM content is saved, the oscillator is frozen, and all the work of the single chip microcomputer stops until the next interruption or hardware reset. The maximum operating frequency is 35MHz, and 6T/ 12T is optional.
2. Infrared module
This design adopts HC-SR50 1 infrared module, which is an "automatic control module" based on infrared technology. The design of LHI778 probe imported from Germany is adopted. With high sensitivity, strong reliability and ultra-low voltage working mode, it is widely used in various automatic induction electrical equipment, especially in automatic control products powered by dry batteries. The module is used to detect whether there are pedestrians passing by at night, thus generating high ground level, and the level signal is processed by software.
3. Photosensitive resistance sensor module
This design adopts 3-wire photosensitive resistance sensor module, which is a sensitive photosensitive resistance sensor. The output of the comparator with clean signal, good waveform and strong driving ability exceeds 15mA. At the same time, it is equipped with an adjustable potentiometer to adjust the brightness of the detection lamp, which is used to detect the intensity of ambient light. If the light intensity is lower than the standard value, turn on the street lamp.
4. Display components
This design uses LCD 12864 to display the time and date. The first line of the LCD screen displays the year, month and day, and the second line displays the real-time clock. The data port of 12864 in the hardware circuit is connected to the P 1 port of the single chip microcomputer, and the pins 4, 5 and 6 of the digital tube are respectively connected to P3.0-P3.2 of the single chip microcomputer, and various information is displayed on the LCD screen through the information processing of the single chip microcomputer.
Fourthly, software design.
The main program mainly designs the call of subroutines in each part, which consists of two parts: clock program and display subroutine. After the program is initialized, the infrared module subroutine judges whether there are pedestrians and outputs signals, which are processed by the software. 12864 LCD subroutine mainly consists of receiving the signal sent by the main program, inputting its settings as a mode subroutine, initializing the LCD subroutine, displaying the date subroutine and displaying the time subroutine.
Verb (abbreviation of verb) simulation realization
The software simulation of the system adopts Proteus software. When the system is turned on, the system enters the initialization interface, and the liquid crystal displays the first behavior time information and the second behavior date information. Turn on the light intensity and infrared judgment during the day, and turn on the street lamp at the same time. Set button to manually change the time information.
References:
1. Hu. Principle of single chip microcomputer and its interface technology [M]. Beijing: Tsinghua University Publishing House .2001.7.
2. Proteus in MCS-51&; Application in ARM7 system [M]. Beijing: Electronic Industry Press. 2006.2008+00.
3. The design and simulation of 5 1 series single chip microcomputer based on Proteus by Hou Yubao [M]. Beijing: Electronic Industry Press .2008.8
4. Zhang,, et al. PROTEUS design and simulation of single chip microcomputer system [M]. Beijing: Electronic Industry Press .2007.4
5. Lou Ranmiao, et al. Curriculum Design Guidance of Single Chip Microcomputer [M]. Beijing: Beijing University of Aeronautics and Astronautics Press .2007.7
6. Zhou, et al. 5 1 Series of Single Chip Microcomputer Application and Practice Course [M]. Beijing: Beihang University Press .2008.5
7. Li Gonglin. Principle and application of single chip microcomputer-based on case-driven and Proteus simulation [M]. Beijing: Science Press 20 10.5
8. Xue Junyi Zhang. MCS Series Single Chip Microcomputer and Its Application [M].Xi An: Xi Jiaotong University Press. 1997
9. He Limin. Design of single chip microcomputer application system. [M] Beihang University Press
research contents
Use of infrared module
Single chip microcomputer reading clock chip
Display relevant data with LCD.
Draw a logical diagram
research project
1 Week-Week 2: Write down the graduation design task book and define the design requirements. Consult and collect relevant materials of graduation project. Begin to translate relevant English materials, and be familiar with the related development knowledge of PROTEUS software and single chip microcomputer.
The third week-the fourth week: summarize the literature and write the opening report. Complete the demand analysis of graduation project and determine the system block diagram.
Week 5-Week 6: Scheme demonstration and hardware circuit design. The designed circuit is analyzed and the software design idea is put forward. Preliminary examination of graduation design.
Week 7-Week 8: Software and hardware design and debugging in PROTEUS. Analyze the problems in debugging, improve and re-debug to meet the technical requirements.
Week 9-Week 10: Test the hardware and software circuits as a whole, and modify and improve the program; Mid-term exam of graduation design.
1 1 week-week 12: design and manufacture printed circuit boards; Complete hardware installation and debugging. Complete the software and hardware debugging of the whole system.
Week 13-Week 14: Summarize the research work and write the graduation thesis.
Week 15-week 16: paper revision and review, paper defense.
Characteristics and innovation
The street lamp controller should be equipped with both light control and time control modules, which obey the photometric control first and then the time control, and can meet the requirements of turning on and off the street lamp at a certain luminosity and at a specific time. At the same time, the street lamp is an infrared induction street lamp. Street lamps are divided into energy-saving state and standard state according to the height of campus traffic peak hours. During the peak hours of people and vehicles, such as working hours in the early morning and at 18-23 o'clock in the evening, the street lamp should maintain a continuous standard brightness, but in the middle of the night, the street lamp will turn into an energy-saving state. Through infrared sensing, it will only light up when people and vehicles pass by.