Design of a GSM-Based Biometric Access Control System

Access control systems restrict access to a secured premise or other secured devices (like a safe) only to authorized persons. In this design a biometric (fingerprint based) access control system was developed with added versatility: remotely Adding/Removing users and monitoring the system’s operation via a GSM Phone. The administrator phone sends SMS commands to the system to put it in the desired operating modes (as security situations arise) and to add/remove users of the premise; thus, the system can work both independently and as dictated by the administrator. The main components are a Fingerprint Module, a GSM/GPRS modem, the door & its control circuitry, and an AT89C52 microcontroller. The microcontroller polls the SMS received by the GSM modem, interprets it to puts the system in the desired mode, sends appropriate SCAN/DELETE/ADD command to the fingerprint scanner, opens/closes the door at each access request by any user (registered or not) based on the present system mode and command it receives from the scanner. The microcontroller’s code is written in ASSEMBLY language using KEIL MICRO-VISION3 emulator/debugger. At completion, the system quite responded in the four set modes: it adds/deletes user fingerprints appropriately, shuts-off when instructed, opens/closes the door when a registered fingerprint is recognized, displays messages appropriately on the LCD screen and receives/sends the appropriate SMS to the Administrator’s phone.