San Diego Tech Fest, Spring 2011

Teacher's Award for Most Original, Best Done Project

When appropriate, the teacher selects one project that meets this criteria:

1. The project has never been completed at this school before. (Or not in the last few years.)
2. The project is built and programmed from scratch. (No kits, no downloaded code from the Internet.)
3. The project works flawlessly.

This is that project. Mr. Nevins and his partner constructed a Radio Frequency Identification (RFID) system.

Here is a photo of the project and a description of the main components:

On the left is the main detection unit. Near the top, it contains what looks like a blue printed circuit board with a hole in it. This is the sensor. It is actually a coil that sends a radio frequency signal to any nearby RFID device. At the bottom is a Liquid Crystal Display (LCD) module that prints the status of the device. If the RFID device placed near the sensor is authorized, an 'Authorized' message will appear. In the center, mounted on the wall of the enclosure is the Basic Stamp 2 microcontroller programmed in PBASIC that runs the device.

The black box in the center is a prototype doorway. A little hard to see here, but the front of the box is the clear plexiglass door. Behind you see a gear that is connected to a servo. When an authorized person swipes a valid RFID tag, the servo opens the door to permit entry. The laptop on the right is used to write, edit and download the program to the microcontroller. And at the bottom right, you can see three round devices with white tags. These are the actual 'keys' used to gain access to tht system.

Here, Mr. Nevins shows one of these keys to the class during his presentation. Several of these keys were coded with a valid 10-bit binary number, and one was coded with a 'bad' number. When the valid keys were swiped, the LCD properly identified the person the key identified, and when the 'bad' key was swiped, an unauthorized entry message was displayed.

The project was demonstrated flawlessly twice. First to his classmates (left photo) and later to another electronics class studying radio frequency theory and their instructor, Mr. Benny Simmons, far right in the right hand photo.