Record temperature to computer via serial port

[Alex]

Hi Everyone,

With electric costs going so high, I want to start monitoring the
temperature in my home via the computer and see the best way to program
my A/C to come on and off during the day and at night. I figure the
best way is to rig-up a temperature gauge to the computer via serial
port and write a small Linux script to take the temp and drop it into a
file with a time stamp.

Can someone suggest such a device which would give me this information?
I assume they are floating out there, but searching Google mainly
returned outdated pages for such devices (some going back to 1999) or
just plans on how to build one. Though I don't mind building such a
device, I've never built something like this from the component level
before.

Thanks for any suggestions or ideas on this ...

Alex

[Bob]

Look at a Weather Wizard from Davis. 'davisinstruments.com'

[Dave Houston]

http://froggyhome.com/

[eschuy...@thisadelphiaout.net]

Alex,

If you can do some simple soldering, take a look at the Temperature Data
Logger Kit at
http://www.electronics123.com/s.nl/it.A/id.379/.f?sc=8&category=69662
It comes with one sensor, but can handle up to four. It outputs the
temperature in Fahrenheit or Celsius in a simple format that's easily
logged on a PC. It's cheap too, only $21.80 + S/H.

A similar device which also keeps track of high and low temperatures for
each sensor can be found at http://store.qkits.com/moreinfo.cfm/VK011K (kit
at $29.95) or http://store.qkits.com/moreinfo.cfm/VK011 (assembled/tested
at $39.95).

Regards,
Eric

[Dave]

You may want to look into this:
http://www.phanderson.com/tm127.html
Dave

[Charles Sullivan]

If you're interested in an X10 approach, take a look at Smarthome's
TempLinc 1625 <http://www.smarthome.com/1625.HTML>. It'll transmit
the temperature data over the AC house wiring vi X10 signals so you
can plug in one or more (up to 16) at various places in the house
without extra wiring.

If you also have an X-10 CM11A computer interface (~$30), the
TempLinc is fully supported by the (free) HEYU software for
Linux, Unix, and Mac OS X <http://www.heyu.org>. Timestamped
temperature data can be automatically written to the HEYU log file.

(With the CM11A and HEYU, you can do a lot of other great home
automation stuff too.)

Regards,
Charles Sullivan

[Konnexman]

Hi!

Dave, have you thought on the possibility of daisy chaining the
temperature sensors with a rs485 pc card? If that exists :)

[Konnexman]

Google - rs485 temperature sensor

[AZ Woody]

Check into the Dallas one-wire devices. You can get a 1-wire to serial (or
USB) adapter for about $20, and each device (sensor) is in the range of
$1-$2. The wiring I use is cat3 or cat5, and multiple sensors can be hooked
to the same run (based on length, I wouldn't suggest more that 15-20).
Dallas provides demo code and drivers for windows and Linux, and the ones
I've used were written in C. The app I wrote started as 1-wire only, but
I've since added support for x1-10 with a cm15a (version linux only).

The temp sensors I use are in to92 packages (look like a transistor), and
have a few located around the house. You can find more info by googling
DS18S20 and probably find a bunch of sites with info (or DS18B20)

Check out homeauto dot usandthem dot com, in the section for the cm15a for a
bit more info, and a link to an email where you can reach me.

"Dave" <cheapsc...@yahoo.com> wrote in message
news:1154390860.6...@s13g2000cwa.googlegroups.com...

[Konnexman]

Charles,

That is a great way of doing this temperature monitoring, but you have
to take into account that to have a reliable temperature mettering, you
must place your sensors at 150cm from the floor.

Cheers!

[Charles Sullivan]

The TempLinc sensor is connected to the transmitting unit with a 6 foot
cable (or optional 12 foot cable) so appropriate sensor placement is
normally not a problem.