Introduction
In this project we will use IR sensors for person detection entering in garageWe will use linear keypad for entering password for door autorisation. If person entered correct password then our IR system will get deactivated.If person entered wrong password then buzzer will get activated. If not entered then shutter will shut down automatically. We are using TV remote to open the shutter .
Microcontroller provide a signal to the motor circuit. Motor is not directly connected with the microcontroller. For the safety of the main processor we interface the motor with optocoupler circuit. Here we use pc 817 ( 4 pin opto coupler) to interface the micro controller with the motor circuit. We use H bridge circuit with the motor. H bridge basically control the movement of the motor. With the help of this H bridge we change the direction of the motor. We use four transistor circuit with each motor. We are using four transistor circuit. Out of these four transistor two transistor is NPN and two transistor and PNP transistor. One NPN and One PNP provide a one direction voltage and motor moves on one direction. Second NPN and second PNP transistor again change the direction of the motor automatically.
WELCOME TO THE WORLD OF THE MICROCONTROLLERS.
Look around. Notice the smart “intelligent” systems? Be it the T.V, washing machines, video games, telephones, automobiles, aero planes, power systems, or any application having a LED or a LCD as a user interface, the control is likely to be in the hands of a micro controller!
Measure and control, that’s where the micro controller is at its best.
Micro controllers are here to stay. Going by the current trend, it is obvious that micro controllers will be playing bigger and bigger roles in the different activities of our lives.
So where does this scenario leave us? Think about it……
The world of Micro controllers
What is the primary difference between a microprocessor and a micro controller? Unlike the microprocessor, the micro controller can be considered to be a true “Computer on a chip”.
In addition to the various features like the ALU, PC, SP and registers found on a microprocessor, the micro controller also incorporates features like the ROM, RAM, Ports, timers, clock circuits, counters, reset functions etc.
While the microprocessor is more a general-purpose device, used for read, write and calculations on data, the micro controller, in addition to the above functions also controls the environment.
We have used a whole lot of technical terms already! Don’t get worried about the meanings at this point. We shall understand these terms as we proceed further
For now just be aware of the fact, that all these terms literally mean what they say.
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This circuit known as the H-bridge (named for its topological similarity to the letter “H”) is commonly used to drive motors. In this circuit two of four transistors are selectively enabled to control current flow through a motor.
Components required:
MCU 89S51
IR sensors
TSOP 1738
Microswitch for keypad
Crystal 11.592 MHz- 1 nos.
On/off Switch- 1 nos.
Diodes IN 4001- 10 nos.
Optocoupler 817- 2nos.
Cap 10µf,0.1 µf,330µf
Transistors -547or 548
Resistances 330 Ω,8.2kΩ,30pf
LED
IC7805 voltage Regulator
Motors dc
Infrared sensors set
Copper Clad board
Ply board
Ferric Chloride
Wires
Soldering iron
Soldering wire
Flux
Universal Programmer
Hardware required-
8051 programmer universal kit
CRO 20 Mhz
Digital multimeter
Software required:
Keil software- Microvision 2
ORCAD for PCB design 10.5
Proteus for simulation 7.4 version
ADVANTAGES
· Low cost
· Reliable
· Portable
· Flexible due to microcontroller
· Easy to use- system is very easy to understand
Applications:
· Automatic garage
· Door access control
· Home security Application