Password Based mostly Door Lock System utilizing 8051 Microcontroller is an easy venture the place a safe password will act as a door unlocking system. Conventional lock methods utilizing mechanical lock and key mechanism are being changed by new superior methods of locking system. These methods are an integration of mechanical and digital gadgets and are extremely smart. One of many outstanding options of those revolutionary lock methods is their simplicity and excessive effectivity.

Such an computerized lock system consists of digital management meeting, which controls the output load by way of a password. This output load could be a motor or a lamp or another mechanical/electrical load.

Right here, we developed an digital code lock system utilizing 8051 microcontroller (a Password based mostly Door Lock System utilizing 8051 Microcontroller), which offers management to the actuating the load. It’s a easy embedded system with enter from the keyboard and the output being actuated accordingly.

This technique demonstrates a Password based mostly Door Lock System utilizing 8051 Microcontroller, whereby as soon as the proper code or password is entered, the door is opened and the involved individual is allowed entry to the secured space. Once more, if one other individual arrives, it’ll ask to enter the password. If the password is fallacious, then door would stay closed, denying entry to the individual.

Building and Output Video

Really useful Studying: Digital Code Lock System utilizing Single Transistor

Precept Behind the Circuit

The primary part within the circuit is 8051 controller. On this venture, a 4×Four Matrix Keypad is used to enter the password. The password which is entered is in contrast with the predefined password.

If the entered password is appropriate, then the system opens the door by rotating door motor and shows the standing of door on LCD. If the password is fallacious, then the door is stays closed and shows “PWD is fallacious” on LCD.

Circuit Diagram of Password Based mostly Door Lock System


Password Based Door Lock System Circuit Diagram

Parts Required

{Hardware} Necessities

  • 8051 Microcontroller
  • 8051 Growth Board
  • 8051 Programmer
  • 4×Four Matrix Keypad
  • 16×2 LCD
  • L293D Motor Driver Board
  • DC Motor
  • 10KΩ Potentiometer
  • Connecting wires
  • Energy Provide
  • If 8051 Growth Board shouldn’t be used, then the next elements are wanted.
    • 11.0592 MHz Quartz Crystal
    • 2 x 33pF Ceramic Capacitors
    • 2 x 10 KΩ Resistor (1/Four Watt)
    • 10 µF Capacitor (Polarized)
    • Push Button
    • 2 x 1 KΩ Resistors (for pull up)

Software program Necessities 

  • Keil µVision IDE
  • Willar Programmer
  • Proteus (for circuit diagram and simulation)

The best way to Design Circuit of Password based mostly Door Lock System?

Password based mostly door lock system utilizing 8051 microcontroller circuit design makes use of 5 main elements – a Microcontroller, an L293D Motor Driver, a DC Motor, a 4×Four Matrix Keypad and a 16×2 LCD. Right here, an AT89C52 Microcontroller is used and it’s an 8-bit controller. This controller requires a provide voltage of +5V DC. With a view to present regulated 5V DC voltage to the controller we have to use 7805 energy provide circuit. We will use 9V DC battery or 12V, 1A adaptor as an influence supply.

Reset Circuit Design: The reset pin of the microcontroller is saved lively until the facility provide is within the specified vary and a minimal oscillation stage is maintained.  In different phrases to make sure the provision voltage doesn’t falls under the edge stage of 1.2V and the reset pulse width is bigger than 100ms (advisable for 89C52),  we have to choose the values of resistor and capacitor such that RC >=100ms.  Therefore, we chosen a 10KΩ resistor and a 10µF electrolytic capacitor.

Oscillator Circuit Design: An 11.0592MHz crystal oscillator is used to supply exterior clock sign to the microcontroller. To make sure clean operation, we have to join two ceramic capacitors within the vary of 30pF to 40pF. This crystal oscillator is related between pin 18 and 19 of the microcontroller. Right here, we used two 33pF capacitors.

Interfacing LCD, Keypad and Motor Driver: First, a 10KΩ Potentiometer is related to the LCD Show’s Distinction Modify Pin (Pin 3). RS, RW and E of LCD are related to P3.0, GND and P3.2 pins respectively. The eight information traces of the LCD are related to PORT1.

The 4 ROW pins of the Keypad are related to P2.Zero to P2.Three and the 4 COLUMN pins of the Keypad are related to P2.Four to P2.7 pins respectively. The IN1 and IN2 of (1A and 2A) of the L293D Motor Driver are related to PORT0 pins P0.Zero and P0.1. Motor is related between OUT1 and OUT2 (1Y and 2Y) pins of L293D.

Compilation of Microcontroller Code: As soon as the circuit is designed and drawn on a chunk of paper, the subsequent step is to write down and compile the code. Right here, we used the Keil µVision software program to write down this system in C language.

Previous to writing the code, common steps must be adopted like creating a brand new venture and deciding on the goal system or the required microcontroller. As soon as the code is written, we have to put it aside with .c extension after which add it to the supply file group below the goal folder.  The code is then compiled by urgent F7 key.

As soon as the code is compiled, a hex file is created.  Within the subsequent step, we use Proteus software program to attract the circuit. The code is dumped into the microcontroller utilizing an exterior programmer and Willar Software program.

Advocate Studying: Password Based mostly Circuit Breaker Undertaking Circuit Diagram and Working.

Password Based mostly Door Lock System Circuit Simulation Video

Earlier than going to learn the working of this circuit, Watch the next simulation video to get clear concept about how the above circuit works.


Password Based mostly Door Locking System Circuit Operation

As soon as the circuit is powered ON, microcontroller sends instructions to the LCD to show “enter password” on LCD.  Now we have to enter the password utilizing the keypad. As soon as password is entered, it shows 5 stars on LCD to point that controller learn password efficiently.

Now the controller compares the entered password with predefined password. If the password is matched, then the microcontroller makes P0.Zero HIGH and P0.1 LOW, so the motor driver will get the enter alerts for ahead movement of the motor.

Consequently, the Door Motor rotates in ahead route to open the door. After a delay of 10seconds, the microcontroller makes P0.Zero LOW and P0.1 HIGH, so the motor driver will get the enter alerts for reverse movement. Consequently, the Door motor rotates in reverse route to shut the door.

If the password shouldn’t be matched, then microcontroller maintains each P0.Zero and P0.1 LOW. Therefore, the door motor is stationary in order that door stays closed.

NOTE: Whereas giving the connections, make it possible for there isn’t any frequent connection between AC and DC provides.

Password Based mostly Door Lock System Algorithm

  1. Initially, declare the PORT1 to LCD information pins and management pins (RS and E) to P3.Zero and P3.2. Additionally, declare PORT2 to keypad. Additionally use P0.Zero and P0.1 for motor driver.
  2. Then, show the message “enter password” on LCD.
  3. Now learn the 5 digit password from the consumer.
  4. Evaluate the entered password with the saved password.
  5. If password is appropriate, then make P0.Zero pin HIGH and P0.1 pin LOW to open the door. Throughout this time, show “Door opening” on LCD.
  6. After a while, make P0.Zero pin LOW and P0.1 pin HIGH to shut the door and after this show “Door closing” on LCD.
  7. If the password is fallacious, then show “Flawed Password” on LCD.
  8. After some delay once more ask to enter password.

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Benefits of Password Based mostly Door Lock System

  • This venture offers safety
  • Energy consumption is much less
  • Used generally obtainable elements
  • Undertaking is straightforward and straightforward

Purposes of Password Based mostly Door Lock System

  • This easy circuit can be utilized at residential locations to make sure higher security.
  • It may be used at organizations to make sure approved entry to extremely secured locations.
  • With a slight modification this Undertaking can be utilized to manage the switching of masses by way of password.

Limitations of Password Based mostly Door Lock System

  • It’s a low vary circuit, i.e. it isn’t potential to function the circuit remotely.
  • If you happen to neglect the password it isn’t potential to open the door.


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