Connecting a Biometric Fingerprint Device to a Rails Web App Using Python — A Complete Walkthrough

👋 Introduction When I was building a gym management system for a real gym in New Delhi, one of the most interesting challenges was connecting a physical biometric fingerprint device to my cloud-hosted Ruby on Rails app . The gym wanted to: ✅ Track member attendance via fingerprint scanning ✅ Automatically deny access to members with expired subscriptions ✅ Prevent duplicate check-ins ✅ See attendance on the admin dashboard in real-time The catch? The biometric device only speaks to the local ne