Web Server Building Block
By Brian Wilson
How small can a Web server be? We all seem to get a kick out of Web servers installed in matchbox-size cases, but wonder what they can really do. Case in point: I took the soda-can size CerfCube to work and showed it to my co-workers (all embedded-software developers). I was disappointed by their initial reactions, "Cute, but what can it do?"
While the diminutive CerfCube might draw attention, it has much more to offer than just its size. To fully appreciate the CerfCube, you have to get creative. For example, you could build a portable network intrusion detection system around it, which is configurable via its Web server. Another idea is to build a dial-on-demand/network firewall using an external modem from CerfCube's serial port. This uses only 2.5 watts (5 watts if you add a Compact Flash card), so it's ideal for applications that require appliances to be on continuously or to run on battery power.
Inside the CerfCube
The CerfCube is built into a three-inch cast aluminum cube. Inside are a 192 MHz StrongArm processor, 32MB of RAM, and 16MB of Flash memory. On the back you'll find a 10T Ethernet, a serial port, and USB connectors. The cube comes pre-installed with Linux or Windows CE; I tested the Linux version. I hooked it up to my network, connected the provided serial cable to my PC, started a terminal program, and plugged in the power supply. The CerfCube booted in 20 seconds and presented a Linux login prompt in the terminal window.
