Smart Door Lock

Project Overview

An IoT door lock system that uses an ESP8266, a solenoid lock, and a biometric sensor for secure, keyless entry.

Bill of Materials (BOM)

• ESP8266 microcontroller
• a Solenoid lock
• a Biometric (fingerprint) sensor
• a relay module
• and a suitable power supply for the lock.

Circuit Diagram & Component Arrangement

Follow the wiring diagram below. Each component connects to specific pins on the microcontroller. Use a breadboard for prototyping and ensure all connections are secure before powering on.

Wiring Summary: The biometric sensor is connected to the ESP8266 for user authentication. Upon a successful scan, the ESP8266 sends a signal to the relay module, which then switches power to the solenoid lock, unlocking the door.

Step-by-Step Procedure

1. Step 1 - Prepare Components: Gather all components from the BOM. Inspect for damage and verify ratings.
2. Step 2 - Breadboard Layout: Place the microcontroller on the breadboard. Arrange components for clear wiring paths.
3. Step 3 - Power Connections: Connect VCC and GND first. Ensure proper polarity for polarized components.
4. Step 4 - Signal Wiring: Connect sensors and actuators per the wiring table. Double-check pin assignments.
5. Step 5 - Upload Code: Connect USB, load the sketch, and upload. Verify serial output if applicable.
6. Step 6 - Test & Calibrate: Power on and test each function. Calibrate sensors if needed.
7. Step 7 - Enclosure (Optional): Mount in a 3D-printed or custom enclosure for durability.

Safety Notes

• Always disconnect power before making wiring changes.
• Use appropriate eye protection when soldering.
• Adult supervision is required for makers under 16.
• Do not exceed voltage ratings of components.