The Arduino Internet Gizmo consists of an Arduino, a RFID card reader, a bunch of LEDs and other components mounted in a recycled PC power supply case connected to a PC as shown in the first diagram. The Arduino is running software that will read an RFID card when it is placed near the reader. When a card is read, the Arduino makes the LEDs on the top of the gizmo light up in sequence and appear to race around in circles. The RFID card's ID is then sent to the PC via a USB cable that connects the Arduino and the PC. On the PC, a Python program is running in a loop waiting for data from the Arduino. When it receives the RFID card id from the Arduino, it looks up the RFID card ID in a table to see what web site is associated with that card. If it finds the card in the table, it opens a new tab in the default web browser for the computer and loads the web site. If the RFID card ID is not in the table, the Python program creates a simple HTML page with an error message and the RFID card ID and displays the information in a new tab in the browser (as shown in the third image). When the Arduino Internet Gizmo is powered on, it illuminates a set of red-green-blue color changing LEDs to indicate that the gizmo is operational.
The second figure and the attached PDF file show the circuit schematic for the Arduino Internet Gizmo. The RFID card reader is connected the Arduino pins 3 and 4. Pin 3 is used for sending the RFID card data to the Arduino and pin 4 is used to enable or disable reading. Arduino pins 6 - 13 are used to control the illumination of the LEDs on top of the gizmo. Arduino pin 5 is used to turn on the red-green-blue LED color changing circuit. Pin 5 connects to an optocoupler that turns the color changing LED circuit on and off. I used the optocoupler circuit rather than connect the color changing LEDs directly to the Arduino because the color changing LEDs draw varying amounts of current as they change color and with five of them, I wasn't sure what effect that would have on the Arduino, so I felt it was better to use the optocoupler and power the color changing LEDs independently.
Details on how the software works is covered in step 20.
More information on how the RFID card reader works can be found in the data sheet for the Parallax serial RFID card reader