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Automatic Parking Fee Management System Based on Single Chip Control
[Abstract]:
Introduces an automatic temporary parking lot fee management system based on single chip 89C51. It adopts the infrared detection method to compute the parking fee, which is better than the traditional methods. It can compute the parking fee automatically, query and show the parking area state in real time, print the information, open and close the parking lot gate automatically, change the charge standard at any moment, it also can be installed, debugged and used easily, and the cost is low. The system will solve the fee management problem in parking lot completely.
[Keywords]: Single Chip Control; 89C51; Infrared Detection; Parking Fee Management
0 Introduce
With the growth of economy, more and more people buy the cars. A surge in car parking Spaces, and a shortage of parking space, stop Yard management fee concerns, especially a temporary halt to the big supermarket Yard management fee more difficult
1 the existing parking fee management system
The current parking fee management system usually adopt the following two kinds Charging:
(1) camera billing way: in the parking lot entrances place a respectively Camera, through the camera under the car license plate number, sent to MCU Or computer processing. Then through calculation of the single chip microcomputer parking time and cost, And control the door open. The solution requires a larger informative Storage capacity, the software design of complex, high cost.
(2) credit card billing way: the owner to the designated place for IC card, Through punching in and out of the parking lot, and through the IC card payment. But the way more Suitable for a long-term fixed parking parking in the parking lot.
In order to solve the shortcomings of traditional billing methods above, the author designs A temporary parking lot based on 89 c51 single chip microcomputer automatic parking fees Management system. This system adopts the infrared detection microcontroller billing way, The required storage capacity is small, possess the function of automatic closed their doors open, since Dynamic pricing, display (display parking lot status), query functions And print function, and charging method can adjust, make the system more spirit Activity. The whole system operation is simple, low cost, easy installation and debugging, Can satisfy the requirements of the management of temporary parking lot.
2 system framework and work process
2.1 system framework
According to the functional division, the temporary parking fee management system is divided into seven Big modules,
(1) infrared detection module: installed in the station entrances and exits, and each Yard of pass in and out of a parking space, used to detect the car door and a parking space Signal and MCU make corresponding processing. By infrared detection module Line of transmission circuit and infrared receiving circuit. The receiving circuit again Divided into the door infrared receiving circuit and the parking space infrared receiving circuit.
(2) the door control module: collaboration with infrared detection module, execution The parking lot, doors open and close function.
(3) the single-chip microcomputer control center: using 89 c51 single chip microcomputer system, it is the core part of this system, the main function is to monitor the state of the keyboard, place Manage the operation of the keyboard input information; Monitoring parking state, control gate Timing starts after the open and close, have a car into the parking space, the car out of a parking space After the stop time, will stop time conversion for the parking fee information; control The display shows all kinds of information as required; The printing process control information.
(4) parking status display module: show parking lot status signals. Yellow light said in and out of the car is in processing; Green says more space; The red light said full stadium parking lots, and cars are not permitted to enter.
(5) the digital tube display module: stop all kinds of information, including Beijing time, parking Spaces, parking time, space, parking fees, business Total, fee standards, and operating hints, etc. This module USES eight Yang digital tube display static and save the cost.
(6) operating keyboard module: through the 4 * 4 keyboard (16 switch group Into the ranks of the array) for a variety of artificial operation, including display, query Information, modify the charge standard, calibration (Beijing time), print the currently displayed Capacity, etc.
(7) miniature printer module: choose TP mu P - 40 a, print invoices And the total turnover.
Among them, the keyboard module, digital tube display module, the parking lot State display module, miniature printer module and single-chip microcomputer control center As the center control circuit.
2.2 the working process
When the car pass or parked in a parking lot, infrared detection module Will inform SCM cars in and out, SCM according to the parking lot State control of doors opening and closing of the parking lot, parking time calculation And cost, and send the display, printer, dealing with the keyboard Shown, query, modify requirements. Parking fee standards for n yuan /hour, more than Regardless of the 30 minutes in an hour meter. The system can also act as a clock.
3 working principle of the infrared detection module
Infrared detection module is the main modules of this system. This section will Introduced the working principle of the module.
3.1 infrared transmitter
As shown in figure 2, infrared emission circuit including a distance apart Two infrared transmitters D3 and D4 to launch infrared beam. Two pieces of NE555 timer chip constitute a multivibrator, first Only 0.67 KHz, the output on the one hand, to the second oscillator 4 feet (21 KHZ square wave), modulation of it, the final output To light up D3 and D4; On the one hand to IC5 as the clock signal, control The opening and closing of the gate.
3.2 infrared receiver
The infrared beam to the infrared receiving circuit TSOP1738 respectively(0) and TSOP1738 (1), if the two beams of infrared beam is blocked, Received circuit output is 1, and output is 0, pulse trigger after processing Broken, send single-chip microcomputer processing, as the car pulled out into the yard, or a parking space The signal. Parking space infrared receiving circuit as shown in figure 3 (the door red Perimeter receiving circuit is similar, but reduces the decline set in the trigger A monostable trigger 74121).
Infrared receiver TSOP1738 for collector output form Type, two infrared beam to the infrared receiver U1, U2, respectively. When the infrared beam is not block by a car, U1, U2 output of 0 v, such as The fruit of the beam is blocked output + 5 v level respectively. So only when the two of them Infrared beam was blocked, U1, U2 just output level, + 5 v Don't sent to increase delay trigger and decrease delay trigger integrated monostable trigger U4, U5, make 74121 output pulse OUT1 and OUT2, sent to 74 ls148 decoder, priority for cars in and out of the interruption of parking Spaces Number. When the car into the parking space, single chip microcomputer system at this time Send corresponding between RAM, when the car out of a parking space, single chip microcomputer to take again The system time of the time, and initial time is presupposed, and time Parking is the total time, and give the corresponding RAM.
4 the design of the single chip microcomputer control center
All the signals in the single-chip microcomputer control center controls the system input, Processing and output, link modules organically, it is the system The core of the part.
4.1 hardware setup
The control center using 89 c51 single-chip microcomputer system. Because the system Storage capacity is not big, so only use internal RAM is 89 c51 But, don't need outside enlarge RAM. The microcontroller using electricity and reset button Circuit, internal clock frequency of 12 MHZ, through software system the clock. T0 timer is set to the highest interrupt priority, guarantee the accuracy of the system time .
In the I / 0 interface on the set of single chip microcomputer P0 port as a data port, P0.0 ~ P0.7 respectively with the micro printer DB0 ~ DB7 even. P1.0 ~ P1.5 as an external interrupt source extension. P2.0 ~ P2.2 and respectively Red, green, yellow light is linked together, as a parking lot state signal lamp.
Automatic parking fee management system to deal with interrupt more (package Sail in and out of a parking space suspend for the suspension of enclosed car in the parking lot, etc.), and And require a response quickly, so adopt the method of software query Don't interrupt priority queue can meet requirements. This system USES Extension 74 ls148 priority encoder microcontroller external interrupt source, corresponding no With the interrupt processing (such as start and stop time, billing, etc.), and send Display shows.
Single-chip microcomputer control circuit diagram centre (included in the center control circuit) is more complex, due to the limitation of space, here to omit it.
4.2 the program design
The single chip microcomputer control center using MCS51 assembly language program write, efficiency is higher. The main procedures are:
(1) the main loop program: for internal RAM, and a variety of interruption, constantly scanning the keyboard, make corresponding operation, and send the display. According to the system requirements, the flow of main loop program as shown in figure 4
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(2) a line program: complete invoice or sales information to print work Can. Print invoice will also remove the parking parking information.
(3) switch display subroutine: 4 x 4 return key on the keyboard can be cut In display (Beijing time), the number of slots, the parking information (including parking Spaces, stop
Total time, parking fee), record and displays a status for the print A subroutine is used. Show parking information, if you can't display all at the same time Content, can be displayed by turn, the key switch on. Initialization time is shown In Beijing time.
(4) the F3 key operating subroutine: F3 of 4 * 4 keyboard function Key is mainly used for various data query, set standards and calibration of Beijing Time.
(5) timer interrupt service routine: MCU internal system clock the clock, the program sets the clock to 24-hour, and fix the clock Number of units.
5 the knot language
Traditional way of parking there are some deficiencies, for these Insufficient, designed a adopts the infrared detection microcontroller billing method new automatic parking fee management system, provide a temporary parking lot a simple operation, low prices, and effective management measures. This System of the actual development use will greatly save the temporary parking management Cost and manpower, and improve the use efficiency of temporary parking lot.
Reference
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[2]xiaoting he, etc. electronic system design. Zhejiang: zhejiang university press, 1998
[3]yachen lingmu, transistor circuit design (third edition), Zhou Nasheng (eds). Beijing: Science press, 2006
[4] electronics, tsinghua university classrooms. Digital electronic technology base. 1997
[5] huaguang kang. Electronic technology foundation for digital part (fourth edition). Beijing: higher teaching Education press, 2002
