Welcome to another exciting IoT project by Yarana IoT Guru — the Smart Attendance System using ESP32 and 4G LTE Module!
This project demonstrates how we can build a powerful attendance tracking system that works completely without WiFi by using a 4G LTE module to send HTTP requests to a cloud server.
In most IoT projects, ESP32 uses WiFi for internet communication — but what if you’re in a remote location or your device is installed in an area without WiFi?
That’s where 4G LTE connectivity comes in! Using modules like SIM7600, SIM7000, or A7672, you can directly connect your ESP32 to the internet via mobile network, just like your smartphone does.
This project can be used for:
- 🏫 School & college attendance management
- 🏢 Office employee attendance
- 🔒 Access control systems
- 🏗️ Construction or field-site worker logging
- 🚪 Smart door logging and monitoring
By the end of this tutorial, you’ll understand how to:
✅ Interface ESP32 with a 4G LTE module
✅ Send HTTP requests using AT commands
✅ Create a PHP API for cloud storage
✅ Design a MySQL database for attendance data
✅ View logs online via browser
⚙️ Required Components
| Component | Description | Quantity |
|---|---|---|
| ESP32 Development Board | Controls the system & communicates with LTE module | 1 |
| 4G LTE Module (SIM7600/A7672/SIM7000) | Provides 4G connectivity & sends HTTP requests | 1 |
| RFID Sensor (RC522) | Detects card UID | 1 |
| LCD Display (I2C) | Displays user and status info | 1 |
| Jumper Wires | For connecting all components | – |
| Breadboard or PCB | For prototyping | 1 |
| 5V DC Power Supply | For stable operation | 1 |
🔌 Circuit Explanation
1️⃣ ESP32 ↔ LTE Module:
- TX2 (GPIO17) → RX of LTE
- RX2 (GPIO16) → TX of LTE
- GND → GND
- 5V → VCC of LTE
2️⃣ ESP32 ↔ RFID (RC522):
- SDA → D21
- SCK → D18
- MOSI → D23
- MISO → D19
- RST → D22
- 3.3V → VCC
- GND → GND
3️⃣ LCD Display (I2C):
- SDA → D4
- SCL → D5
The setup ensures seamless communication between all devices. The LTE module handles HTTP communication while the ESP32 processes logic and card data.
💡 Working Concept
Whenever a user taps an RFID card, the ESP32 reads the card’s unique ID (UID).
Then, using AT commands, it sends the data as an HTTP POST request to a PHP API hosted on a cloud server (for example, a cPanel or local web host like XAMPP).
The PHP script stores the UID, attendance type (IN/OUT), signal strength, and battery info into a MySQL database.
When the same card is scanned again, the system automatically toggles between IN → OUT or OUT → IN, creating a smart attendance log that shows who entered or exited and at what time.
All records are time-stamped automatically in MySQL, making this a reliable and WiFi-free attendance system.
🧠 Code Explanation
The project consists of two main parts:
1️⃣ ESP32 firmware (Arduino Code)
2️⃣ Cloud Backend (PHP + MySQL)
🎓 Playlist Description (By Yarana IoT Guru)
🧾 4G LTE IoT Series Overview
Welcome to the official 4G LTE IoT Series by Yarana IoT Guru!
Here, you’ll explore next-level IoT projects that run entirely on mobile networks — no WiFi needed.
Each project focuses on real-time automation, sensor data collection, and remote control using HTTP requests and cloud servers.
Projects include:
✅ RFID-Based Smart Attendance System
✅ 4G LTE Smart Home Automation
✅ IoT Sensor Cloud Dashboard
✅ Cloud Logging & Data Visualization
You’ll learn to:
- Send HTTP GET/POST requests using 4G modules
- Interface ESP32 with LTE devices like SIM7600 or A7672
- Upload sensor data to MySQL cloud databases
- Create your own IoT dashboards
🎥 Every tutorial includes:
✔️ Circuit Diagram
✔️ Complete Source Code
✔️ API Development Guide
✔️ Live Cloud Demonstration
👉 Learn, Build, and Automate — with Yarana IoT Guru, your IoT learning partner.
Subscribe now to explore the future of wireless IoT!
🔚 Conclusion
This Smart Attendance System using 4G LTE Module and ESP32 is not just a project — it’s a step toward next-generation IoT systems.
You can deploy it anywhere — schools, factories, construction sites — where WiFi isn’t available.
Using HTTP requests over LTE, you can log, store, and access real-time attendance data from anywhere in the world.
Developed and demonstrated by Yarana IoT Guru, this project bridges the gap between offline environments and cloud IoT ecosystems.
It’s practical, reliable, and scalable — the future of wireless automation! 🌍
💡 Learn | Build | Automate with Yarana IoT Guru
🔔 Subscribe now on YouTube to master IoT with ESP32 + 4G LTE!
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