Project Hub /Security Surveillance & Defense/Smart Door Lock (Keypad/App/OTP)/ESP32 Cam-Based Smart Bluetooth Lock

Intermediate

ESP32

Project Specific

3 – 6 Hours

Partial Kit

ESP32 Cam-Based Smart Bluetooth Lock

Design a keyless and RFID-less smart door lock using an ESP32 Cam module connected via Bluetooth to a smartphone for password-based access.

Originally published on ElectronicsForU

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

ESP32 CAM WiFi Module Bluetooth with OV2640 Camera Rs. 810.00
USB to UART/ESP8266 Adapter Programmer for ESP-01 WiFi Modules with CH340G Chip Rs. 99.00
5V 1 Channel Relay Module Rs. 45.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: Solenoid / Electric Lock

Browse all components

How It Works

The ESP32 Cam-Based Smart Bluetooth Lock system operates by combining wireless communication, microcontroller logic, and electromagnetic actuation to achieve keyless door access. At the heart of the system is the ESP32 DevKit v1/ESP32 Cam module, which runs custom firmware developed via the Arduino IDE. This microcontroller hosts a Bluetooth server capable of pairing with a standard smartphone running a Bluetooth terminal app. When an authorized user inputs a matching password through the smartphone app, the terminal transmits this string wirelessly via Bluetooth to the ESP32 Cam. The microcontroller processes the received data, comparing it against a pre-programmed access string stored in its memory. If the credentials match, the ESP32 changes the state of its digital output pin connected to the relay module. The relay acts as an electrically operated switch, isolating the low-voltage control logic of the microcontroller from the higher-current DC power supply required by the physical solenoid lock. Once triggered, the relay closes the circuit, supplying power to the solenoid lock to retract its bolt and open the door. Connecting wires tie the entire circuit together, while an external power supply ensures stable operation for both the ESP32 module and the electromechanical lock.

Why Build This

Design and prototype a functional IoT-based keyless entry system suitable for smart home automation and modern office security integration.

Gain practical experience interfacing low-level microcontrollers with high-current electromechanical actuators like relay-driven solenoid locks.

Implement wireless human-machine interfaces by bridging mobile Bluetooth terminal applications with embedded microcontroller firmware.

Real-World Application

Keyless home entry systems, smart office door locks, and secure IoT-based enclosures.

Skills You'll Learn

Bluetooth serial communication

relay control and isolation

electromechanical actuator interfacing

microcontroller firmware development

serial programming via FTDI

Safety Precautions

Ensure correct wiring when interfacing high-voltage relays or DC power supplies with the microcontroller to avoid short circuits.

Technology Tags

ESP32

BLUETOOTH

IOT

SMART LOCK

ARDUINO IDE

SOLENOID LOCK

FTDI PROGRAMMER

Frequently Asked Questions

Can I use a standard USB cable to program the ESP32 Cam?

No, the ESP32 Cam module typically lacks an onboard USB-to-UART bridge, so you must use a dedicated FTDI programmer to upload your code from the Arduino IDE.

Why is a relay module necessary between the ESP32 and the solenoid lock?

The ESP32 digital pins operate at 3.3V and can only source a few milliamperes of current, which is far too weak to drive a power-hungry solenoid lock directly; the relay uses a low-power control signal to safely switch the higher external power required by the lock.

What kind of smartphone application do I need to unlock the door?

Any generic Bluetooth terminal app available on your mobile device's app store can be used to scan, pair, and send text-based password commands to the ESP32.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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