Core Service
IoT System Development
Connected system design spanning devices, firmware, communications, data flow, and operator-facing interfaces.
- Connected device architecture
- Sensor integration
- Firmware development
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IoTClient ProjectCompleted Prototype
RFID-Based Attendance System
A fast and reliable ESP32-based attendance system using RFID cards, local SD-card storage, a 1.3-inch OLED display, captive-portal configuration, and battery backup.
An ESP32-based RFID attendance system designed for reliable daily use. It supports local and offline attendance storage on an SD card, a compact OLED user interface, captive-portal configuration, and backup power operation.
Project Snapshot
- Category
- IoT
- Project Type
- Client Project
- Status
- Completed Prototype
- Date
- Jul 13, 2025
- Application Areas
- Attendance Monitoring, Access Systems, Connected Devices
- Related Services
- IoT System Development, Embedded Systems Development, Hardware Prototyping
Implementation Notes
Overview
The RFID-Based Attendance System is a compact attendance-recording device built around the ESP32.
Users tap an RFID card to record attendance, while the device provides immediate status feedback through a 1.3-inch OLED display.
Offline Data Storage
Attendance records are stored locally on an SD card, allowing the system to continue recording data even when network connectivity is unavailable.
This makes the device suitable for environments where continuous internet access cannot be guaranteed.
User Configuration
A built-in captive portal allows users to configure device settings through a phone or computer without modifying the firmware.
This simplifies setup and makes the system easier to install and maintain.
Hardware
- ESP32 microcontroller
- RFID reader
- RFID cards
- SD card module
- 1.3-inch OLED display
- 5 V power adapter
- battery backup system
- status and control electronics
- protective enclosure
Key Features
- fast RFID attendance recording
- local and offline data storage
- 1.3-inch OLED status display
- Wi-Fi configuration through captive portal
- ESP32-based embedded control
- battery backup during power interruption
- compact and reliable design
- easy device configuration
System Flow
RFID Card → RFID Reader → ESP32 → Attendance Record → SD Card
The OLED provides immediate user feedback, while the captive portal is used for device configuration.
Current Status
The system was developed as a completed working prototype combining RFID identification, embedded control, offline storage, local user feedback, and configurable Wi-Fi functionality.
It provides a practical attendance solution designed to remain functional even when network connectivity is unavailable.
Related Services
Firmware & Device Logic
Embedded Systems Development
Firmware-focused development for microcontroller-based systems, sensor interfaces, device logic, and hardware integration.
- ESP32 firmware development
- Embedded C/C++ implementation
- UART, I2C, SPI, and GPIO integration
Proof of Concept
Hardware Prototyping
Prototype-oriented engineering for evaluating sensors, modules, power approaches, and early connected-system ideas.
- Proof-of-concept development
- Sensor evaluation
- Microcontroller selection
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