Building an Open Source "Clicker"?

fieldtest asks: "Most Slashdot readers have read about "clickers", remote control style devices that students use to wirelessly answer a teacher's questions. Unfortunately, as a college student, I have had less than stellar experiences with these clickers. I hear complaints from my professors and fellow students often as well. So, I want to build an open source clicker system for all universities to use. I believe that this is a prime opportunity to show how powerful free software can be. So, what do the talented people of Slashdot recommend?" "The problem is this: a clicker system requires...clickers. What I need are remote controls that have a minimum of 6 buttons (for users to select options with). The sticking point comes when a button is pressed -- the remote must send the option choice, as well as a unique ID specific to the remote, so the clicker software can distinguish between different students.

I've experimented and Googled around. I've tried standard TV remote controls combined with an USB-UIRT receiver, but the range was too low. Googling shows some interesting programmable remotes, but they're far too expensive ($100+) to have each user purchase one.

How should I go about building the perfect clicker and receiver system? Any suggestion is welcome, from IR to radio, from Bluetooth to ZigBee based communications. Recommend a commercial product, or a do it yourself solution. Please also recommend a receiver device, and a way to connect it to a computer. Also, if you recommend that I just build a custom circuit board for the remote control, please give some references and examples of how it should be implemented."

Comments

Try these Cypress chips

[Savantissimo]

www.cypress.com
CY7C601xx
CY7C602xx
About $3-$5 in quantity
Development kit: CY3655 $350

(also check out their wireless USB products)
* Wireless enCoRe(TM) II -"enhanced Component
Reduction"
o Crystalless oscillator with support for an external crystal or resonator. The internal oscillator eliminates the need for an external crystal or resonator
o Configurable IO for real-world interface without external components
* Enhanced 8-bit microcontroller
o Harvard architecture
o M8C CPU speed can be up to 24 MHz or sourced by
an external crystal, resonator, or signal
* Internal memory
o 256 bytes of RAM
o Eight Kbytes of Flash including EEROM emulation
* Low power consumption
o Typically 10 mA at 6 MHz
o 10-A sleep
* In-system reprogrammability
o Allows easy firmware update
* General-purpose I/O ports
o Up to 36 General Purpose I/O (GPIO) pins
o High current drive on GPIO pins. Configurable 8- or 50-mA/pin current sink on designated pins
o Each GPIO port supports high-impedance inputs,
configurable pull-up, open drain output, CMOS/TTL
inputs, and CMOS output
o Maskable interrupts on all I/O pins
* SPI serial communication
o Master or slave operation
o Configurable up to 2-Mbit/second transfers
o Supports half duplex single data line mode for
optical sensors
* 2-channel 8-bit or 1-channel 16-bit capture timer. Capture timers registers store both rising and falling edge times
o Two registers each for two input pins
o Separate registers for rising and falling edge capture
o Simplifies interface to RF inputs for wireless
applications
o Internal low-power wake-up timer during suspend
mode
o Periodic wake-up with no external components
* Programm