Abstract
This project presents the development of an RFID-based embedded security system using the AT89S52 microcontroller. Radio Frequency Identification (RFID) technology provides a reliable and low-cost method for automatic identification and access control.
The RFID reader detects passive RFID tags within a range of approximately 2 inches and transmits a unique identification code through serial communication at a baud rate of 9600 bps. The microcontroller processes the received data and validates the card information.
If the card is valid, the system activates a DC gear motor to open the gate. If the card is invalid, the system denies access and generates a buzzer alert.
Introduction to RFID Technology
RFID (Radio Frequency Identification) is a wireless technology used for identification and tracking. It consists of:
- RFID Tag
- RFID Reader
- Microcontroller
- Output Devices (Motor, LCD, Buzzer)
RFID systems are widely used in:
- Access control systems
- Inventory tracking
- Attendance systems
- Payment systems
- Vehicle security
System Components
Microcontroller – AT89S52
The AT89S52 microcontroller processes the RFID data and controls the motor, LCD, and buzzer.
RFID Reader
The RFID modem communicates with the microcontroller using serial communication (9600/4800 baud rate).
LCD Display (16×2 – HD44780)
Displays system status messages such as:
- “Access Granted”
- “Access Denied”
Motor Driver – L293D
The L293D IC drives the DC gear motor that controls gate movement.
Voltage Regulator – 7805
Provides regulated 5V power supply and eliminates voltage noise spikes.
Working Principle
- RFID tag is placed near the RFID reader.
- Reader sends tag ID to microcontroller via serial port.
- Microcontroller compares tag ID with stored valid IDs.
- If valid:
- Motor rotates and gate opens.
- LCD displays “Access Granted”.
- If invalid:
- Buzzer sounds.
- LCD displays “Access Denied”.
- After 30 seconds, gate automatically closes.
Technical Specifications
Hardware
- Microcontroller: AT89S52
- Crystal Frequency: 11.0592 MHz
- Serial Driver: MAX232
- LCD: 16×2 (HD44780)
- Motor Driver: L293D
- RFID Modem
- DC Gear Motor: 10 RPM
- Transformer: 12V Step-down
- Filter Capacitor: 1000µF / 25V
- Voltage Regulator: 7805
Software
- Keil MicroVision
- Proteus
- UC Flash
Applications
- Shopping malls
- Auditoriums
- Offices
- Secure access doors
- Industrial gates
This RFID based system provides reliable access control. For enhanced smart security integration, you may also check our Smart Based Security Access Control System.