tail -f ZS64.log

Measuring temperature in a PC should be easy: after all, most mainboards have extensive monitoring capabilities for temperature and voltage levels built-in. Unfortunately, very few of these facilities are documented properly, and software support is lacking. Instead of trying to navigate the maze that is lm-sensors (which isn’t even available for FreeBSD), I decided to look for some USB-based solution.

There’s a reasonably cheap chinese USB thermometer called TEMPer. I got mine from Brando for 12 Euros. It’s a USB-to-serial chip from WinChipHead. It’s DTR, RTS, and CTS lines are used to connect a LM75 I²C temperature sensor. To talk to the LM75, you need some bit-banging driver.

I’ve put together a command line utility for the TEMPer that can program the built-in thermostat (TEMPer has a LED connected to that output) and print out temperature measurement data. It does it’s job, and might serve as an example on how to do I²C over a simple interface.

If you have trouble with Flash segfaulting in Linux Firefox-3.5.2 (the symptom is a browser hang), I fixed that by downgrading Flash from Flash10 to Flash9. Of course Flash9 is full of security holes. In combination with the Flashblocker Firefox extension and only activating it on trusted sites it seems like a reasonable approach. Of course for all we know the newest Flash10 is full of security problems, too.