A few months back while searching for solutions to automate the observatory’s roof, I came across a small shop on Bulgary that sells USB and Serial relay boards, in various configurations. At the time I bought a couple of USB One Channel Relay Units and they sitted around for a while, while I finished some other small projects.

Today I finished the assembly of the board. I got a small plastic box, that turned out to be a tiny bit smaller that it should, forcing me to chop off a few millimeters at the corners of the PCB, cut a slot on one end for the USB port and power cable, and got a cheap triple extension cord from the local hardware store to make the thing useful.

The final result was this, with a unused board on the side:

To control it, I made a small C# application (.NET 2.0, Windows only), that presents a simple form with a button, and can be controlled from the command line. You can download it here (zip, 5Kb) if it’s useful for something.

To change the COM Port, you should edit HKEY_CURRENT_USER\Software\SigmaPower\COMPort on your registry (the key is created on first run)

To use it from the command line, you should pass it a single parameter: “ON” / “OFF”, or “1″ / “0″. Ex:

c:bin>SigmaPower ON

This one should be installed on the observatory by tomorrow!

From code.flickr via kottke.

Interesting analysis of client-side processing and data transmission…

From typeface’s website:

Instead of creating images or using flash just to show your site’s graphic text in the font you want, you can use typeface.js and write in plain HTML and CSS, just as if your visitors had the font installed locally.

You still a licensed font for this, but there’s tons of open source fonts out there…