[svlug] USB temperature sensor

[John Conover]

Akkana Peck writes:
> > Florin Andrei writes:
> > > Anybody using a USB temperature sensor that works well?
> 
> John Conover writes:
> > 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.
> 
> Maybe the same as the ones here: http://www.aagelectronica.com/aag/
> for which there's a Linux driver ("one-wire") on sourceforge.
> I have no personal experience with them (yet), but I've had them
> recommended to me for Linux use.
> 
> At a somewhat higher price point, Phidgets makes a temperature
> sensor, http://www.phidgets.com/products.php?category=10
> I've noticed phidgets drivers in the mainline kernel, but
> I haven't looked into which phidgets units are supported.
>

Although the original post was for "inexpensive" sensors, there are a
few outdoor 2 X AA battery RF remote thermometers, (like from Taylor,
so one doesn't have to run wire plumbing-good to about 50-100 ft.,)
which have serial/RS232 ports on the receiver-but they are a bit
pricy, at about $75 steet price. The complete weather stations,
(wind/rain/temp.,) run $150-$300+; most are USB, and some Linux
drivers are available.

In most metropolitan areas, http://www.wunderground.com/ (and type in
your zip code,) probably has one of these weather stations online, so
you can suck down weather data, (and history,) for free; its all in
HTML, so the data is easy to parse out-many have ASCII download for
daily and near real time data.

Just for completeness in this thread.

     John

BTW, I put my thermostat under control of a Linux box, with several
different types of temperature sensors, (all the ones above,) and a
month-by-month comparison between two years ago and this and last year
indicates about a 2X reduction in HVAC costs. It knocked it down a
complete PG&E tier. The software is available at
http://www.johncon.com/john/x10/, which can be hacked for the various
serial protocols, (those are really C templates for controlling serial
gadgets.) See:

    http://www.pge.com/tariffs/electric.shtml#TOUDATES
    http://www.pge.com/tariffs/rateinfo.shtml

for tier data.    

-- 

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