The Smart Access Controller implements a multi-layered security system beginning with RFID authentication. Authorized users are identified through their RFID card UID (66 8B F8 04 for users, FA 4D 6C 3 for administrators), after which they must enter a secure PIN code (# for users, 1# for administrators) via the keypad interface. Three failed authentication attempts trigger a security lockdown with visual indication via RGB LED.
Once authenticated, users can navigate through an intuitive LCD menu system to monitor environmental conditions:
- Real-time temperature readings (ºC)
- Humidity levels (%)
- Luminosity values (LDR analog readings)
Administrators gain additional privileges to set threshold values for each environmental parameter. The system automatically activates response mechanisms when thresholds are exceeded:
- Servo-controlled cooling system when temperature exceeds setpoint
- Humidity control via secondary servo mechanism
- Relay-controlled lighting when luminosity drops below configured levels
The system architecture employs an Arduino Mega board with multiple integrated components:
- MFRC522 RFID module for secure authentication
- 4×4 matrix keypad for PIN entry and menu navigation
- 16×2 LCD display for user interface
- DHT11 sensor for temperature and humidity monitoring
- LDR sensor for light intensity measurement
- Servo motors for physical actuation
- Relay module for electrical control
- RGB LED for system status indication
The code implements state management for different operational modes (authentication, monitoring, configuration) and features debounced button inputs for reliable menu navigation. Environmental thresholds are stored in an array structure allowing for easy adjustment and expansion.
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