Smart Door Lock System: A Low-Cost Prototype with Local Fingerprint Authentication and IoT Monitoring

This paper documents a low-cost smart door-lock proof-of-concept with two separate control paths: local fingerprint authentication using an Arduino Uno and an R307 fingerprint sensor, and a Wi-Fi browser interface implemented on an ESP32-CAM. The biometric subsystem includes a relay, a solenoid lock, a 16×2 I²C LCD, and status LEDs. The ESP32-CAM firmware serves a browser page, a camera stream, and an HTTP action endpoint. Source-code inspection found no HTTP authentication, no JSON door-state endpoint, and no signal linking the Arduino’s biometric decision to the ESP32-CAM. The network control endpoint is therefore not protected by application-level authentication in the reviewed implementation. Because independently verifiable trial-level records were unavailable for this revision, quantitative biometric performance claims are not reported. Instead, the paper describes the architecture, firmware behavior, implementation limitations, and security improvements needed before deployment. No formal network penetration or biometric spoofing evaluation is claimed.