Note: All picture labels are located at the bottom of the picture or diagram to which they refer.

Summary:

Our project will consist of an RFID reader which will read in numbers from cards similiar to those used by students and staff to enter the Seaman Center. The RFID reader will send the card number scanned to a server via USB port. The server will search a database to see if that card is authorized to open the door, and if it finds that the user is authorized, it will send a signal to the lock to open it.

We also plan to include an online website on the server that will allow the customer to open the door remotely. The applications for this include the ability for a customer to open their front door while at work so a repair man could enter, allowing a child into the house after school, and so on and so forth.

Schematic 1 shows a basic outline of the system we plan to build.

Schematic 1.

Cost Information:

-RFID Card Reader Serial Price: $39.99
-Boarduino (all parts listed): $25.00
-Relay: $2.00
-Enclosure: $3.79
-Fail Safe Electric Door Strike: $38.96

RFID:

The RFID reader we will be using is produced by Parallax Inc. Click HERE for the reader's data sheet. The Parallax RFID reader is low cost capable of reading passive RFID trasponder tags from up to 1&3/4 to 3 inches away. The RFID reader requires 5V of DC supply, has a bi-color LED to identify activity taking place. The RFID reader includes four pins to connect to power, ground, and the access control microprocessor, which are labeled in the legend below.

Parallax RFID Reader Module.

Parallax RFID Reader Pin Legend

Boarduino:

The final architecture of our lock-access control microprocessor-RFID is still undecided, but we have gotten the Parallax RFID reader working with a Boarduino USB solderless breadboard. The Boarduino is a copy of an Arduino Board--it comes with a chip pre-programmed with the Arduino bootloaderwith--a few noteable differences are:

* Shields cannot be used as the form factor is so different
* There are two versions, a DC version and a USB version
* For the DC version there isn't an on-board USB chip. This means you need to use a USB-TTL cable or a MiniUSB (or any other FTDI breakout board) which is not included. There are also no rx/tx LEDs and no rx/tx 1K series resistors.
* For the USB version, there is an on-board USB chip but there isn't a DC jack or 5V regulator, you can power it through the USB jack. There is a rx 1K resistor so you can use this to talk to serial accessories.
* 16.00 MHz ceramic resonator is used instead of crystal, so cycle speed may be off by +- 0.3nS (0.5%). This isn't relevant for UART timing, servo drivers, PWM, etc. but could be an issue if you need nanosecond-precision timing. Note that the Arduino software only provides millisecond-precision timing for general sketches (1 second = 1000ms. 1ms = 1,000,000 ns)

The Boarduino we've selected to use is powered and sends data to a PC via a USB cord. The USB Boarduino has the following specifications:

The specifics for the USB boarduino include:

* Designed to plug into a breadboard for easy prototyping
* Petite size, only 2.75 " x 0.8" (75mm x 20mm)
* All 'standard' pins are brought out - Digital 0 thru 13, Analog 0 thru 5, ARef, 5V, Ground, 3.3V and Reset
* 2 LEDs, green power and red "pin 13" LED just like the Arduino Diecimila
* Standard Reset button
* ATmega168, running at 16.00 MHz, just like the NG and Diecimila
* 6-pin standard ICSP header
* Standard USB jack
* USB or external power, selectable with a jumper
* 500mA fuse protects your computer from current overdraw
* Auto-reset capability
* Available as a low cost kit with standard parts, so its never out of stock
* All through-hole parts are easy to solder - SMT chip is presoldered & tested when purchased as a kit

Here is a picture of the USB Boarduino, fully assembled.

USB Boarduino.

The official Arduino board website is located at www.arduino.cc/.

The parts sheet for the USB Boarduino is located at www.ladyada.net/make/boarduino/usb-parts.html.

Electric Door Strike:

Electric Door Strike (Seco-Larm SK990A)

-Fail Secure
-Remains locked during outages
-2,500 lb Forcing Strength
-Driven by 12V relay

The door will remain locked during power outages, preventing a security breech should the power shut off.

The specifications for the door strike is located at www.asihome.com.

Relay:

-Relay driven by ATMega168 pin (~25 mA)
-500Ω Coil Resistance
-5V/500Ω = 10 mA < 25 mA

Website:

The website will allow remote users to log in online and remotely unlock the door. The website will include the following parameters.

-Server running Windows Server 2003
-ASP.NET 2.0
-MSSQL Server Database Backend
-Connected to Access Controller via RS-232
-Dynamic DNS Client
-Located in close physical proximity to door being controlled

This part of the project has a great deal of expansion potential. A camera could be added to provide a video feed or snap pictures every few seconds and provide identification of the person being allowed through the door being opened remotely. Opening the door via iPhone or BlackBerry is also an area into which future research could be done. There is also potential to make money off monthly subscriptions for the use of this service for homeowners, or to make money in the set-up and up-keep of such systems for corporate users.