[svlug] USB temperature sensor

[John Conover]

Florin Andrei writes:
> Anybody using a USB temperature sensor that works well?
> 
> I've found a few sensors on-line but I'm not sure how well they actually 
> work on Linux, so I'm trying to find someone who's actually using these 
> things.
>

Florin, if you use a 2.6 kernel, yes. Most look like a USB tty device,
(using the same chip as found in the serial->USB dongles.)

However, make sure you can return the device since not all tty devices
are supported, (some are weird $MS drivers, only, supplied a CD,) and,
or course, it doesn't say that on the packages.

Dmesg(8) will tell you immediately when you plug the device in.

I never got one to work on a 2.4 kernel, but 2.6 has USB drivers for
most of them, (at least Ubuntu and Knoppix do.)

Almost any serial program will work, cu(1), minicom(1), etc., but you
will probably have to hack the protocol, (most just return the
temperature in ASCII in response to a CR, 8 bits, no parity-setting F
or C requires a little more hacking.)

       John

BTW, I don't know how much you want to put into your project, but if
cost is an issue and you have time on your hands, there are Linux
drivers for the "one wire" thermometers from Maxim, (or whatever its
called these days after the merger with Dallas Semi.) These are really
inexpensive-under a buck each. There is also PIC code floating around
that makes a bunch of thermometers mulitiplexed into Linux.

-- 

John Conover, conover at rahul.net, http://www.johncon.com/