NFC Smart Lock App with Dynamic Access Control

What is this?

A mobile security app developed as a group project for the Mobile Development course at university. The app uses email authentication and NFC to unlock doors based on user authorization. It features a role-based access control system, allowing users to manage and share access with configurable time limits, and includes a lock simulation for testing and demonstration.

Check out the demo to get a quick overview of the project!

About my role

• Designed and implemented the Android app frontend for intuitive and secure user interactions
• Collaborated with my teammate on building core features, focusing mainly on the frontend
• Helped with testing and demo preparation

Technologies I used

• Frontend: Android (Java)
• Database: PostgreSQL
• Authentication: Firebase (email-based authentication and role-based access control)

Features

User features

• Passwordless sign-in for quick access
• Create and configure new locks
• Share lock access with others, with configurable time limits
• Receive notifications when access is shared
• Unlock doors using NFC with proper authorization
• View access logs to track unlock events
• Edit lock details and manage access permissions

Management features

• Role-based access control for users
• Lock CRUD operations

Challenges & how I approached them

1. Learning Android development on the fly

• This was my first Android project, so I was essentially learning as I developed. I had to quickly get up to speed while making sure we could deliver the app on time.
• To overcome this, I actively sought help from my teammate and the course TA, breaking down tasks into manageable steps and focusing on completing my parts reliably.
• Also our project idea was quite ambitious. To demo the NFC lock, we needed to develop a mock app in addition to the main Android app, which added extra workload under a tight deadline. Therefore, my teammate built the demo quickly on iOS using a familiar framework, while I focused on the Android app.

2. Integrating APIs and managing UI state

• Integrating the backend API into the Android frontend and reflecting accurate UI states was challenging, especially as I was new to Android development.
• I spent quite some time doing research online to figure out how to properly handle different responses (e.g. locked/unlocked status) and update the UI accordingly, ensuring a smooth user experience.

So, what was the outcome?

• Earned an A grade for the project
• Delivered a functional Android app demonstrating an NFC smart lock with role-based access control, and presented it clearly with a working demo

Things I learned

• Gained hands-on experience with Android (Java) development, particularly API integration and managing UI state based on backend responses
• Learned passwordless authentication and role-based access control using Firebase for the first time
• Developed a stronger understanding of native mobile app architecture and development workflows