On May 1, 2012, at 3:39 PM, Ellen K. Wilson wrote:

[trimmed]

> This got me thinking about the top two suggestions in the library's feedback box - 1) we want a coffee shop and 2) it's too cold/hot in the library. I figure I covered number one by throwing in some Javascript on the page (*groan*) but I see an opportunity with the second one. We do have microclimates within the library, so while it may be hot on 3N, chances are good it's freezing on 4S. Given that actually fixing this is beyond the library's control, what if we put wireless temperature sensors throughout the building and displayed their readings on the library homepage?
> 
> So, if one were to attempt this:
> -How would you go about it? (hardware- or software-wise)
> -Could it be done for cheap?
> -Would it be OCLC-approved?

There exist USB-connected temperature sensors, so if you already have a machine on each floor already, you can connect them up, then use something like MRTG to generate graphs. ... but it looks like the current going price on the THUM sensors is $120 each:

	http://practsol.com/thum.htm

(we use them to monitor the offices that have mission-critical systems in them ... other people might not be willing to shell out that much)

It looks like cheaper ones exist, but some have some really bad reviews on Amazon, and any of the thumbdrive looking ones are going to need extra cabling to move it somewhere away from the computer.

	http://www.amazon.com/TEMPer-USB-Thermometer-w-Alerts/dp/B002VA813U/
	http://www.amazon.com/Powered-Thermometer-Temperature-Sensor-Data/dp/B0054U4YKI
	http://www.amazon.com/Extech-RHT10-Humidity-Temperature-Datalogger/dp/B001AFFVWQ/

... you might need to read up on the features, as I seem to recall that some were more the 'it collects data, and then you connect it up via USB, but you can't get it to record while it's connected', which make 'em pretty useless for this.

If you don't have a machine there already, you should be able to get one of the 'wall wart' PCs for ~$100.

...

Your other option is to have one monitoring system, and then have lots of remote sensors that you'd have to run cable to ... I know my roommate's done it before, but I think the serial adaptor that they were all connected to was in the $200 range, and then ~$10 per sensor.  And it's not really worth it unless you have some sort of cabling already in place.  (the ones he was using could run over cat5 or other twisted pair)

If you have lots of corners & nooks which tend to be cooler/hotter than others, this might be the better option as you don't need a full machine for each one, even if it means needing to run cabling.  (I'll have to check on the exact details of what he's using; prices have likely changed since he filled be in on the stuff he was doing ~2 years ago)

...

And if you're willing to do some soldering yourself, you could get it even cheaper per sensor:

	http://www.adafruit.com/category/35_56


-Joe

ps.  my only experience with wireless temp. sensors was trying to monitor my greenhouse from my kitchen (LaCrosse, not computer connected) ... I think I baked it, as it died once we hit summer, never to come back again.