RFID Door Lock

What is it?

The RFID Door Lock allows my parents and family to unlock their front door without the use of traditional keys. When somebody with an RFID tag on their person appraoches the door, the tag is automatically and wirelessly scanned. Assuming that the tag's unique idenity matches an entry in the lock's table, the door will unlock. Feedback is provided to the user via an LED in the doorbell. For example, the doorbell will light green upon seccessfully unlocking. The door will automatically lock itself a few seconds later, forever eliminating the problem of forgetting to lock the door when leaving the house. This concept also eliminates the problem of lost keys, due to the fact that each tag is unique. Replacing a lost key is as simple as buying a new one (~$1), I have found that this is actually cheaper than most traditional keys. There is also no need to worry about having to change the locks, as each key is unique. An individual tag can be removed from the system without effecting any others.

About the Lock

This was a project of mine devised to fufill the requirements of my High School Senior Graduation Project. My installation of this type of lock builds upon the many others in the fact that the installation is completely hidden. The build pics are captioned explaining each part of the system. Since installation, I have modified and improved several parts of the system allowing it to be installed in / at almost any house / door.

The Code

The "base" code (as well as inspiration) for this project came from a similar setup by Brett Martin designed for easy access to his homebrew equipment. You can download some code to get you started from his Website or his Instructable, both are great resources. I am currently experimenting with configuration / datalogging using the Arduino's serial port. I plan to post my own version once it is finalized.

Build Pics

Some are better quality than others, I was in a hurry at the time. Click on the thumbnails to view or download a higher quality version.

Front Door with (Completely Concealed) RFID Lock Installed

Access Denied - Doorbell flashes red in response to an unauthorized key.

Access Granted - Doorbell lights green & door unlocks in response to an authorized key.

A side view of the modified doorbell.

RFID Reader PCB embedded in door frame.

The backside of the modified doorbell & RFID Reader.

Closeup of the electromagnetically driven strike.

Enclosure containing the lock's Arduino driven controller as well as relevant power supplies.