project
December 13, 2021
11 min read
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Smart Door Lock
An IoT door lock system that uses an ESP8266, a solenoid lock, and a biometric sensor for secure, keyless entry.
<h2>Project Overview</h2>
<p>An IoT door lock system that uses an ESP8266, a solenoid lock, and a biometric sensor for secure, keyless entry.</p>
<h2>Bill of Materials (BOM)</h2>
<ul>
<li>ESP8266 microcontroller</li>
<li>a Solenoid lock</li>
<li>a Biometric (fingerprint) sensor</li>
<li>a relay module</li>
<li>and a suitable power supply for the lock.</li>
</ul>
<h2>Circuit Diagram & Component Arrangement</h2>
<p>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.</p>
<p><strong>Wiring Summary:</strong> 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.</p>
<h2>Step-by-Step Procedure</h2>
<ol>
<li><strong>Step 1 - Prepare Components:</strong> Gather all components from the BOM. Inspect for damage and verify ratings.</li>
<li><strong>Step 2 - Breadboard Layout:</strong> Place the microcontroller on the breadboard. Arrange components for clear wiring paths.</li>
<li><strong>Step 3 - Power Connections:</strong> Connect VCC and GND first. Ensure proper polarity for polarized components.</li>
<li><strong>Step 4 - Signal Wiring:</strong> Connect sensors and actuators per the wiring table. Double-check pin assignments.</li>
<li><strong>Step 5 - Upload Code:</strong> Connect USB, load the sketch, and upload. Verify serial output if applicable.</li>
<li><strong>Step 6 - Test & Calibrate:</strong> Power on and test each function. Calibrate sensors if needed.</li>
<li><strong>Step 7 - Enclosure (Optional):</strong> Mount in a 3D-printed or custom enclosure for durability.</li>
</ol>
<h2>Safety Notes</h2>
<ul>
<li>Always disconnect power before making wiring changes.</li>
<li>Use appropriate eye protection when soldering.</li>
<li>Adult supervision is required for makers under 16.</li>
<li>Do not exceed voltage ratings of components.</li>
</ul>
M
Manish Bookreader
Electronics enthusiast, Embedded Systems Expert, Linux/Networking programmer, and Software Engineer passionate about AI, electronics, books, and cooking.
