A compact embedded access-control system that reads RFID tags over a UART interface and grants or denies access by driving a DC servo motor. Firmware parses UIDs from the RFID reader, checks them against an authorized list, and logs access attempts over serial.

• Embedded C – bare-metal firmware development
• Keil µVision IDE – for compilation, debugging, and simulation
• Flash Magic – for programming LPC2129 via UART bootloader
• Serial terminal (via RS-232) – for UART debugging and monitoring
• GitHub – for version control and documentation

• LPC2129 ARM7TDMI development board (with inbuilt 12 MHz crystal oscillator)
• EM-18 RFID reader (UART interface, reads tag UIDs)
• 16x2 alphanumeric LCD (displays access status)
• DC servo motor (rotates to unlock when access granted)
• RS-232 cable (for UART debugging with serial terminal)
• Power supply, connectors, and passive components

1. On power-up, the LPC2129 microcontroller initializes the UART interface, LCD display, and servo motor, and loads the list of authorized UIDs into memory.
2. When an RFID tag is presented, the EM-18 reader transmits its UID over UART.
3. The firmware parses the UID and compares it against the stored authorization list.
4. If the UID is valid:
   • Servo motor rotates to unlock
   • LCD displays "Access Granted"
5. If the UID is invalid:
   • LCD displays "Access Denied"
6. After a short timeout, the servo returns to the locked position and the system resumes listening for new tags.