Things used in this project

Software apps and online services

Story

📖 Project Story — B y Yarana IoT Guru

Security is one of the most important aspects of modern smart homes. Every day, we rely on locks, passwords, and keys — but what if you could unlock your door just by saying a command or by recognizing your face?

That’s exactly the idea behind my project — the Voice-Controlled Security Door Lock using ESP32 + Face Detection, one of the most advanced and exciting IoT + AI projects I’ve built so far as Yarana IoT Guru.

💡 The Inspiration

Traditional door locks are simple but limited — they need keys.Smart locks improved that with Wi-Fi and Bluetooth, but they still depend on apps or PINs.

I wanted to take it a step further — create a lock that combines Artificial Intelligence (AI) and IoT, giving the user the freedom to control access both by voice commands and by facial recognition.

This means:

You can say “Hey Google, unlock the door” using Google Assistant + IFTTT + Blynk.

• You can say “Hey Google, unlock the door” using Google Assistant + IFTTT + Blynk.

Or the system can automatically unlock when it detects your face via ESP32-CAM.

• Or the system can automatically unlock when it detects your face via ESP32-CAM.

It’s a dual-authentication smart door lock — powered by ESP32, running with cloud integration, and capable of both voice control and AI-based face detection.

🧩 The Idea and Concept

The project’s concept was to build a completely wireless, cloud-connected, AI-powered security door system that works seamlessly even without human contact.

Here’s how it’s designed:

ESP32-CAM handles face detection and recognition. When a known face is detected, it sends a signal to unlock the door.

• ESP32-CAM handles face detection and recognition. When a known face is detected, it sends a signal to unlock the door.

ESP32 main board is connected to a relay module that physically drives the electronic door lock or solenoid.

• ESP32 main board is connected to a relay module that physically drives the electronic door lock or solenoid.

Voice Control is achieved using Google Assistant + IFTTT + Blynk Cloud.

You simply say: “Ok Google, open the door.”

• You simply say: “Ok Google, open the door.”

The command triggers IFTTT, which sends a signal to Blynk Cloud, and finally to your ESP32 device to unlock.

• The command triggers IFTTT, which sends a signal to Blynk Cloud, and finally to your ESP32 device to unlock.
• Voice Control is achieved using Google Assistant + IFTTT + Blynk Cloud.You simply say: *“Ok Google, open the door.”*The command triggers IFTTT, which sends a signal to Blynk Cloud, and finally to your ESP32 device to unlock.

A manual override button is also added for emergency control.

• A manual override button is also added for emergency control.

So, the door can be unlocked three ways — face detection, voice command, or manual press — making it both smart and practical.

⚙️ Hardware Setup

The hardware includes:

ESP32-CAM for face recognition

• ESP32-CAM for face recognition

ESP32 NodeMCU for cloud communication & voice control

• ESP32 NodeMCU for cloud communication & voice control

Relay Module to drive the lock

• Relay Module to drive the lock

12V Solenoid Lock or Door Strike

• 12V Solenoid Lock or Door Strike

Power Supply (5V for ESP32 & 12V for lock)

• Power Supply (5V for ESP32 & 12V for lock)

Both ESP32 boards communicate either via serial or Wi-Fi (local network). The ESP32-CAM constantly streams video and detects faces using onboard AI models.

When your face is matched, it sends an HTTP signal to the main ESP32 board that activates the relay for a few seconds — unlocking the door.

💬 Voice Control with Google Assistant + IFTTT + Blynk

To make the system voice-controlled, I integrated Google Assistant using IFTTT (If This Then That).Here’s how the flow works:

Google Assistant listens for a specific command (like “Open Door”).

• Google Assistant listens for a specific command (like “Open Door”).

IFTTT receives this command and triggers a webhook.

• IFTTT receives this command and triggers a webhook.

The webhook sends an HTTP request to Blynk Cloud, updating a virtual pin.

• The webhook sends an HTTP request to Blynk Cloud, updating a virtual pin.

The ESP32 reads that pin and activates the lock relay.

• The ESP32 reads that pin and activates the lock relay.

Everything happens almost instantly — within a second or two — and the system provides real-time feedback via LED indicators or mobile app status.

🧠 Face Detection Logic

The ESP32-CAM uses its built-in AI image recognition library for detecting and identifying faces.I trained the module by adding multiple photos of authorized users via the ESP32-CAM web interface.

Once trained, it automatically recognizes faces in real-time:

If it detects a known user, it sends a success signal to unlock the door.

• If it detects a known user, it sends a success signal to unlock the door.

If it detects an unknown face, it remains locked and can send an alert (optional feature).

• If it detects an unknown face, it remains locked and can send an alert (optional feature).

This ensures that even if someone tries to enter without permission, the system remains locked and can optionally notify the owner via the Blynk app.

🌐 Cloud Integration

To make the system truly IoT-based, I used the Blynk IoT platform.Blynk acts as a middle layer between the ESP32 and cloud commands — handling both manual app control and voice triggers.

With the new Blynk 2.0 dashboard, you can easily monitor:

Lock status (Locked/Unlocked)

• Lock status (Locked/Unlocked)

Last unlock event

• Last unlock event

Connected device info

• Connected device info

Everything syncs in real time, whether you use Wi-Fi, mobile data, or even remote Google voice commands.

🔐 Safety Features

Security was a major focus for this project.I added several layers of safety to ensure reliability:

Face recognition accuracy >85%

• Face recognition accuracy >85%

Auto lock reactivation after a few seconds

• Auto lock reactivation after a few seconds

Manual reset button for local control

• Manual reset button for local control

Encrypted API keys for cloud requests

• Encrypted API keys for cloud requests

Optional buzzer alert for unauthorized access attempts

• Optional buzzer alert for unauthorized access attempts

The system is built not just to be cool — but actually secure for daily use.

🧰 Challenges Faced

During development, the hardest part was managing two ESP32 boards — one handling AI vision and the other handling cloud I/O.Synchronizing both in real-time without lag required optimizing Wi-Fi bandwidth and managing delays properly.

Face recognition under low light was another challenge, which I solved by adding a small LED flashlight near the ESP32-CAM lens for better illumination.

🚀 Final Results

After testing, the results were amazing — the lock opened instantly when a recognized face appeared or when I used the Google command.The combination of AI + IoT + automation worked flawlessly.

It felt futuristic to walk up to the door, have it recognize me, and unlock — all without a key or phone touch.

This project proves that AI + IoT integration isn’t just possible, it’s accessible for makers and students.

🧩 Real-World Applications

Smart Home Security Systems

• Smart Home Security Systems

Office and Lab Access Control

• Office and Lab Access Control

Hostels and Apartments

• Hostels and Apartments

AI-based entry systems for schools or IoT labs

• AI-based entry systems for schools or IoT labs

It’s scalable, low-cost, and highly reliable.

🎬 The Yarana IoT Guru Touch

Every part of this project — from hardware connections to Blynk setup and IFTTT automation — is documented step-by-step on my YouTube channel: Yarana IoT Guru.

This project combines AI (Face Detection), IoT (Voice + Cloud Control), and real hardware automation — all explained in detail for students and enthusiasts who want to learn modern IoT systems.

It’s not just a door lock — it’s a demonstration of how future smart homes will work, where AI recognizes you and IoT listens to your voice.

🏁 Final Thoughts

The Voice-Controlled Security Door Lock with ESP32 + Face Detection is the perfect example of what happens when AI meets IoT.It’s secure, modern, and completely touchless — ideal for today’s smart home generation.

It represents the next step in home automation — a system that recognizes you, listens to you, and protects your home.

💬 Built and documented by Yarana IoT GuruWatch full tutorial and source code on YouTube: Yarana IoT Guru

💬 Built and documented by Yarana IoT GuruWatch full tutorial and source code on YouTube: Yarana IoT Guru

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Code

Credits

Thanks to Yarana IoT Guru.