CAR PARKING SYSTEM
Introduction:
In the project Car Parking System we have shown the concept of an automatic car parking system. As in the modern world everything is going automatic we have built a system which will automatically sense the entry and exit of cars through the gate and then display the number of cars in the parking lot. Even we can set a maximum capacity of cars with the help of user interface given in the hardware in the form of switches so that there is no congestion. We have deployed a microcontroller which is used to sense the movement of cars and depending upon whether there is a capacity of cars to enter, it either opens the gate or not. It is also possible to open a gate when any car enters in the parking lot or close the door when a car exits from the parking lot.
There are two sets of sensors: one on the first gate (entry gate) and one on the second gate (exit gate). When a car arrives at the door the microcontroller receives the signal from the entry sensors and then checks whether there is a capacity of cars to be accommodated. Simultaneously it will also display the number of cars present in the parking lot on a LCD screen and also opens the gate. When a car moves out of the parking area the microcontroller reduces the count displayed accordingly and also closes the gate. The user will have an option to set the maximum count for the cars with the help of switches connected to the microcontroller.
The sensing of entry and exit of cars is done with the help of Infrared transmitters and receivers. Before the door the Infrared transmitter is mounted on one side and the receiver is placed directly in front of the transmitter across the door. When a car arrives the Infrared beam is blocked by the car and the receiver is devoid of Infrared rays and its output changes. This change in output is sensed by the microcontroller and accordingly it increments the count and opens the door if there is some capacity. The procedure for the exit of the cars is similar as the entry.
Block Diagram of the Project:
Microcontroller unit:
Microcontroller used in the project is AT89s52. This part is the heart of the project. It checks for the entry and exit of the car. It continuously polls the pins from where we receive the signal from the intruder circuits.When it detects the car from the entry gate then it checks whether there is any vacant space in the parking lot. If there is vacant space then it opens the door and increases the over all count in the parking lot by one. And after 3 seconds automatically closes the door. And if it detects the car from the exit gate then it decreases the count by one.
Interfacing with switches (keypad):
Interfacing with keypad makes instrument menu driven user friendly. This will help to the user to select the maximum capacity of the parking area.
Display unit (LCD)
LCD makes this instrument user friendly by displaying everything on the display. It is an intelligent LCD module, as it has inbuilt controller which convert the alphabet and digit into its ASCII code and then display it by its own i.e. we do not required to specify which LCD combination must glow for a particular alphabet or digit.
Stepper Motor:
Stepper motor is used to open and close the door. It is interfaced with microcontroller and takes command from the microcontroller to rotate some particular specified angle. It can be interfaced with MCU as shown below:
The switching circuit is comprises of an optocoupler which will isolate the controller from the outer spikes or fluctuations or from the external hardware and at the same time it drives a power transistor i.e. make it on when a signal from the controller pin is applied to it. Optocoupler actually comprises of a diode and a phototransistor. It comes in a DIP IC package. Thus signal from the MCU is given to the LED part or the driving part. When LED begins to glow then the phototransistor acts as on switch or short circuit. This output is given to power transistor, which will amplify the current of the signal and then use it to drive winding of the Motor. Ground is directly given to the common of the Motor. And +vcc is provided to the motor winding through the amplifier.
If user wants to switch ON the Motor winding, then the microcontroller is sending a signal to the optocoupler then ultimately that supply to that winding is ON. Reverse is the case when MCU does not send any signal and thus, supply to that winding is OFF.
Intruder:
The 555 timer is used in the Infrared transmitters and receivers. At the transmitter it is used to produce a pulse of 38 kHz. This pulse is then fed to the Infrared LED so that it produces bursts of Infrared energy at the rate of 38 kHz. The reason of transmitting frequency being this much particular value is that the Infrared receiver (i.e. TSOP 1738) works at maximum efficiency when the Infrared rays falling on it, are of 38 kHz. At the receiver the 555 timer is used to pass the output of the Infrared receiver to the microcontroller. We are using the 555 timer in mono- stable operation where one external resistor and capacitor control the pulse width. The 555 timer has a number of features. When there is a person between receiver and transmitter then the trigger pin gets low due to which at the output pin of timer we get a high pulse. This high pulse is applied to the pin of microcontroller which in turn senses this pin and activates the next task.
NC
A
1
1
Monday, January 01, 2001
Title
Size
Document Number
Rev
Date:
Sheet
of
0
COMMON
Q1
BC547
1
2
3
3
K1
RELAY SPDT
3
5
4
1
2
TO MICROCONTROLLER GROUND
4
TO MICROCONTROLLER PORT 2.1
8
R1-100K, R2-1K, R3-470E, R4-47K
6
R1
R
D1
PHOTODIODE
1
2
7
C1-22MF/25V, C2-104PF
5
IR LED
1
+
C2
CAP NP
0
_
IR LED
12V DC
555 IC
C1
C
NO
INTRUDER SENSOR
D2
R4
R
R2
R
R3
R
2
NC
A
11Monday, January 01, 2001
Title
SizeDocument NumberRev
Date:Sheetof
0
COMMON
Q1
BC547
1
2
3
3
K1
RELAY SPDT
3
5
4
1
2
TO MICROCONTROLLER GROUND
4
TO MICROCONTROLLER PORT 2.1
8
R1-100K, R2-1K, R3-470E, R4-47K
6
R1
R
D1
PHOTODIODE
12
7
C1-22MF/25V, C2-104PF
5
IR LED
1
+
C2
CAP NP
0
_
IR LED
12V DC
555 IC
C1
C
NO
INTRUDER SENSOR
D2R4
R
R2
R
R3
R
2
Entrance or Exit Detector:The entrance or the exit of a person in the room is detected by using two infrared modules. Each module will contain an IR transmitter and an IR receiver. Before the door the Infrared transmitter is mounted on one side and the receiver is placed directly in front of the transmitter on the other side of door. Infrared transmitter will continuously transmit IR waves and the receiver will continuously receive IR waves. The IR transmitter will use an IR LED. This LED can transmit IR whenever it is supplied from a 5-volt voltage source. The receiver can either be photodiode if the width of the door is less or a special IR receiver known as the IR eye. Now whether a person enters or exits, the beam of each module will be interrupted that is the output from the two receivers which actually is the pulse output from two different monostable multivibrator using 555 timers. Thus the outputs from the two receivers are in the form of pulse.
BLOCK DIAGRAM FOR IR RECEIVER
O/P TO MCU OUTPUT IR INPUT
At the receiver side the IR eye or the IR demodulator will demodulate the IR signal and then give its output to the trigger of a 555 timer, which is mounted as a monostable vibrator. Thus whenever there is an interrupt in the IR beam then corresponding trigger will go from high to low thus the output from the 555 timer will be a pulse which is then generated as in monostable mode by applying a ve voltage at the trigger a pulse is generated.
Features of the Project:
Powered by +5V & +12V supply
Current consumption 0.45mA for Microcontroller circuit, 0.75mA for switching circuit, 200mA for amplification circuit
Automatic detection of any incoming/outgoing car
Automatic opening and closing of entry gate
User interface using LCD and switches
Always display the number of cars present in the Parking Lot
Various Components used in various Modules of the Project along with specifications and quantity:
Power Supply Unit1 (+5V):
S. No.
Component
Specification
Qty.
1.
PCB
Designed
1
2.
Transformer
9-0-9, 500mA
1
3.
Diode
1N4007
4
4.
Cap.
1000 F
1
5.
Regulator
7805
1
Power Supply Unit2 (+12V):
S. No.
Component
Specification
Qty.
1.
PCB
Designed
1
2.
Transformer
9-0-9, 500mA
1
3.
Diode
1N4007
4
