E&TC / ECE · Security and safety system · Final year project

Smart Door Receptionist with Smart Lock System

A smart doorbell and lock built with a Raspberry Pi. When a visitor rings, the camera captures their photo and sends it to the owner online, who can unlock the door remotely.

Components & cost

What is the Smart Door Receptionist with Smart Lock System project?

A smart doorbell and lock built with a Raspberry Pi. When a visitor rings, the camera captures their photo and sends it to the owner online, who can unlock the door remotely.

Key facts

Type
Final year project · Intermediate
Suitable for
Diploma capstone and B.E / B.Tech final year
Build time
4 to 6 weeks
Estimated component cost
₹6,400 – ₹9,400
Guidance from
₹9,999 (Hardware / IoT Final Year)

How the Smart Door Receptionist with Smart Lock System works

  1. 12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V.
  2. The Push buttons and switches provide manual inputs and the power switch.
  3. The Raspberry Pi 4 runs Linux and the main program, handles the camera, networking and heavier processing such as image recognition.
  4. The DC geared motor provides the driving motion.
  5. The Voice playback module with speaker plays recorded voice announcements.
  6. The LEDs indicate status.

Block diagram

Components list and cost

Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.

ComponentQtyWhat it doesApprox. cost
Raspberry Pi 4 (2 GB)1Runs Linux and the main program, handles the camera, networking and heavier processing such as image recognition.₹4,800
Push buttons and switches2Provide manual inputs and the power switch.₹80
DC geared motor1Provides the driving motion.₹250
Voice playback module with speaker1Plays recorded voice announcements.₹280
LEDs (assorted)1Indicate status.₹20
12 V power adapter / step-down transformer1Supplies stable low-voltage power from the mains.₹250
Button1Part from the design specification₹150*
Passive components, PCB and wiring kit1Capacitors (assorted), diodes, resistors (assorted), cables, connectors and jumper wires, ICs and IC sockets, crystal oscillator, transistors / MOSFETs and PCB / breadboard.₹445
Wiring, PCB, soldering and enclosure1Project overhead₹450
Demo model base / mounting board1Project overhead₹500
Testing spares and replacements1Project overhead₹300
Estimated totalVaries with brand, quality and city₹6,400 – ₹9,400

Prices are estimates for budgeting; items marked * depend on the exact size or model chosen. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.

How much does this project cost?

OptionWhat you getCost
Components onlyYou buy the parts and build it yourself₹6,400 – ₹9,400
Hardware / IoT Final YearWorking model or guided build, Circuit diagram and bill of materials, Firmware / code with explanationfrom ₹9,999 + components
Capstone Project (CPE)Working project or model, Black book in MSBTE format, Step-by-step explanation₹9,999 + components
Diploma ITR100% working source code, Project report PDF, PPT₹1,999 + components

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Download the project brief (PDF)

Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.

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What you submit with this project

  • Working model with circuit diagram and program code
  • Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
  • Presentation for the review and final viva
  • Synopsis for topic approval, if your college asks for one

E&TC / ECE viva questions on this project

What is the aim of the Smart Door Receptionist with Smart Lock System project?

A smart doorbell and lock built with a Raspberry Pi. When a visitor rings, the camera captures their photo and sends it to the owner online, who can unlock the door remotely.

Explain the working of your project in short.

12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V. The Push buttons and switches provide manual inputs and the power switch. The Raspberry Pi 4 runs Linux and the main program, handles the camera, networking and heavier processing such as image recognition. The DC geared motor provides the driving motion.

Why did you choose a Raspberry Pi instead of an Arduino?

The Raspberry Pi is a full computer with an operating system, so it can run Python, OpenCV and a web server. An Arduino is a microcontroller that is better for simple real-time control but cannot process images or run multiple programs.

Why is a pull-up resistor needed with a push button?

Without it the input pin floats and reads random values. The pull-up keeps it HIGH until the button connects it to ground.

Why is a geared motor used?

The gearbox reduces speed and multiplies torque, so a small DC motor can move a vehicle or mechanism smoothly. Torque increases roughly by the gear ratio.

How are voice messages played?

Recorded audio files on a micro SD card are selected by the controller through serial commands, and the module's amplifier drives the speaker.

Why is a resistor connected in series with an LED?

It limits the current to a safe value (about 10–20 mA). Without it, the LED would draw too much current and burn out. R = (supply voltage − LED voltage) ÷ current.

Explain the block diagram of your project.

The input section senses the real-world quantity, the Raspberry Pi 4 processes it according to the program, and the output section displays the result and drives the actuators. The power supply section feeds every block.

Which communication protocols are used between the modules?

UART (serial) for the GSM, GPS, Bluetooth or fingerprint modules. Each protocol was chosen because the module supports it and it uses the fewest pins.

What is the operating voltage of the circuit?

The controller and most sensors work at 5 V (ESP boards and some modules at 3.3 V). A 12 V adapter powers the board, and a regulator steps it down. Motors and relays get their own supply line so they do not reset the controller.

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Want to build Smart Door Receptionist with Smart Lock System?

Send your college, deadline and team size. We confirm the scope, cost and what you will submit.