Appendix: Cost Details

RCT-433-AS $2.24

RCR-433-RP $3.53

2 Prototyping breadboards (Free From Lab)

1 Keyboard (Scavenged Old keyboard)

PS/2 Socket $0.40

PS/2 Plug $0.99

2 ATMega32 Processors (Free From Lab)

1 STK 500 board (Free From Lab)

Miscellaneous electrical components (Free From Lab)

Total: $7.16

Note that originally we ordered the Radiotronix RCR-433-HP receiver for $11.29, but we received the RCR-433-RP receiver for $3.53 because the company was out of stock on the receivers which we wished to obtain. The difference between the two receivers is that the HP version has a longer range and it appears to have a more robust receiver design than the RP version we received. Although we can not say for sure, it is possible that if we did obtain the receiver chip we ordered, our keyboard would be more resilient to external interference.