I'd like to know what the temperature is in a small server room (three full size racks, one L shaped desk, lots of shelves all around) .

I could buy some random thermomethers, and stick them to walls / and racks, but I would really like something that sends out an email when a threshold is met.

But, really, nothing more than that.
Is there something that can be connected via USB to a PC? Or maybe a network devices, wired or wireless, that can serve this purpose? Or, any other relatively inexpensive solution anybody would recommend?

Thank you!

I don't know of anything turnkey and cheap. There are however simple kits that you can get for reading the temperature via a PC serial port.

http://www.phanderson.com/tm125.html

Reading the values over the serial port is fairly easy, you then just need a script to email it or use one of the many graphic packages to generate a web page.

I bought a LaCrosse 8610 for this exact purpose. It has an RS232 connection and there is Linux software for it.

The problem is that it works fine for about a day and then gets stuck and fails to update data. It only does this when it's being read from by the Linux software. I've spent many hours trying to figure out the problem to no avail. (The serial protocol is insane. It's like a munged direct memory map.)

I haven't found anything else cheap and ready-made, though I'm sure it would be easy enough to make your own solution with a Dallas 1-wire thermometer.

I had to solve this problem once with zero budget. It was the single most clever thing I've ever done. I'm immensely proud of this.

I had a problem with my server room where, sometimes after a power outage, the HVAC would stop working (it wouldn't automatically start up again correctly after the power outage), and I'd come back after a long weekend to a cooking server room. I tried to get them to fix the HVAC and after about 20 visits they still couldn't fix it. My only solution was to reset the HVAC by hand when it happened. So I needed to know, via email and/or SMS, any time the server room busted a certain temperature threshold so I could go into the office and reset the HVAC.

I'd looked up all the existing devices for monitoring my server room temperature, they were all expensive. Such things exist if you're willing to pay for it: Google on Server Room Climate Monitoring.

But I needed to solve the problem without waiting for my company's purchasing process. So I did the following:

- We had one computer in the server room that was already dedicated to playing MP3s for the music-on-hold system. (We'd been using CD players but they kept breaking down; turns out a computer configured to boot into WinAmp is more reliable than a consumer CD player.)

- Because this one computer was playing music, it was the only computer in the server room with a SOUND CARD.

- Sound cards also have ANALOG JOYSTICK PORTS.

- Analog joystick ports are simply a way to read a resistance value on a couple of pins and turn it into a digital number from 0-255.

- I went to Radio Shack ("Tandy"), and for a couple of bucks, got some thermistors and crimped a couple of plug-pins onto the leads of the thermistors.

- I stuck the thermistors into the X and Y pinouts of the joystick port. (I discovered later had to do both X and Y even though I was only gonna use one of them).

- I wrote a VB program to read the joystick deflection value and send an email if it busted a certain threshold.

There was a lot more to the program than that, but on the surface, that's all it was. It solved my problem perfectly and gave me a chance to write a fun program and learn something new.

That's a cool solution

I am really bad with VB, but I may consider this, just for the fun of it.

Fortunately, I was actually having a very "corporate" approach to "unexpensive". So, I am in fact ok with spending 100-200 Euros on something that reliably lets me measure temp in the server room. As long as it is good. Really. Meaning: doing well what it is asked to do, "forever".

I found this, which is more expensive than what I was planning to spend, but I may be convincing myself to spend that money, once I decide it is a really good device.
Does anybody know this thing?

Also, I found this really cheap sensor, which supposedly can be controlled by simple windows software.

This is kinda silly, but it might do what you want. How about if you pointed a cheap webcam at a big dial thermometer on the wall of the server room?

tanstaafl.

Stick an empeg in the room, and just read it's temperature from the web interface.

Both webcam and empeg are pretty clever solutions, actually But, they do not send out emails when needed, which is what I need in a typical scenario: weekend, AC fails, server room melts down...

I have a product just exactly for this at work. It does EVERYTHING I want it to do. Now if I can just remember what it was called.

Ahh, yes. Here it is. The Molly 304. The logging software kinda sucks, but who cares? Mine is set to go off if the temp reached 74F. If that happens, it fires off an email.

It is not a complete solution, but I have built a few of the K145 sensor boards mentioned on This guy's page and also used his code for a while to log temps. If I can solder something, anyone can.

When it came time to get a more complete solution with email and SNMP we got a couple of units from IT Watchdogs, but then you are talking $200 and up.

I had a similar problem - after a power failure, the building's chillers (which we tied into) wouldn't reset, and our HVAC would overload and go offline. We had to do manual reset. Without AC, it took about 90 minutes for the server room to get so toasty as to wipe our firewall. Just a quick reload from backup, but it sucked on weekends.

I was no where as close to as clever as you, though: I used an APC sensor and device (it seems to have been replaced by a much more expensive "NetBotz" get-up) which sent a half dozen emails to personal email accounts and cell phones in the hope someone was available to drop everything and rush in.

If we got there in time, we could open a couple doors, set up our fans, and keep it barely cool enough indefinitely. Fortunately it only happened about once a quarter.

-jk

I used the Tony solution at home with relatively good results. However, if I was going to be monitoring lots of different points I'd look at the stuff Andy linked to. I've seen someone monitor their entire apartment with that stuff.

Yup, sounds like exactly the problem we had!

Did you come up with the same joystick-port trick on your own, or had you seen me mention it on the BBS before?

An arduino board with the ethernet daughtercard? I got one of these for random hacking and it's pretty sweet. The TCP stack is implemented within the ethernet controller itself, so the micro doesn't have to do much complicated to connect to an SMTP server and squirt data out.

There's likely even some sample code out there for this. Plus, it has multiple ADC channels so easy to hook up multiple thermistors.

Tony, it was a while ago, but I think I remember it being mentioned on the BBS but googled someone who had already documented it. ISTR choosing the right value of thermistor took a couple of goes to get right and I did need 2 of them for it to work.

Hugo, I have a couple of those ethernet shields which I was using for a remote control satellite dish positioner and I agree they are pretty cool, although at the time you had to hack the ethernet library to support UDP.

Funnily enough, I might have to put some temperature sensors in a new project I'm working on. So the plan is to use the same 1-wire temperature sensors and run a cut down SNMP stack on the arduino. I'm using the new 32KB atmegas so there's plenty of space for code. If not I could alway use the new Arduino Mega which is pretty neat. Although I had an early one which meant I had to replace a cap on the board to make it auto-reset properly. It's supposed to have been FITNR. I think that would be the coolest way to do it.

Interesting. I didn't know anyone else had done that same trick.



I got lucky, then. My Radio Shack only had one kind of thermistor.

For me, the reason I needed two of them was that I had to put one on the X joystick axis and one on the Y joystick axis. If I only plugged in one, Windows refused to detect the presence of a joystick and my code to read the joystick deflection wouldn't work.

Yes, that's what I meant, one on X and one on Y.

Yup, just google 'joystick port thermometer', there's a few of them.

The good is it's inexpensive. The bad...

It's intended to operate stand alone, be retrieved and read on a computer.

It only operates from the internal battery, which is not rechargeable. The usb port will not supply power to operate the logger.

When connected to the usb port it presents as a file system containing a csv file containing the logged times and temps.

There is an app that allows setting the log intervals. Longer intervals allows longer operation before the battery gives out.

While we are on about USB loggers, steer well clear of the USB temperature reading stick on DealXtreme. I my experience it doesn't work (which unfortunately describes most of the stuff I have bought from DX).

Did you end up going with any particular product?

My server room AC failed early Monday morning, and my ad-hoc temperature sensor failed before my threshold, so I never got notified.

Until someone came in Monday morning and noticed that there was something funny going on. The server room got up to 140°F (60°C). Holy crap.

So now my manager wants triple redundancy on the climate monitoring.

I'm inclined to go with the ITWatchdogs products — they seem to be well respected — but the fact that they have external power supplies, and direct plug-in ones at that, turns me off. I don't know that I need more than just the one, though, so maybe the PoE module would work fine for me.

Anyway, just thought I'd see if there was any new information.

I personally postponed the purchase, so I have not yet hands on experience.

But I happen to be about to (tomorrow, actually!) buy an AKCP Sensor Probe 8 (http://www.akcp.com/products/sensorprobe-series/sensorprobe8/) .

In fact, I found out that a friend I trust, working in another organization, is using them since years ago, and they seem to just work.

Those products look comparable in scope to the two IT Watchdogs units we have and perhaps even a bit more "industrial" and maybe better fit and finish.

They also have a chainable sensor probe for temp inputs so I am guessing that makes fewer ports go farther.

One thing we got for our primary Watchdog is a combined temp/humidity/airflow sensor for the discharge of our main AC unit. That's nice. One feature I don't see in the AKCP line is a light sensor. Our Watchdog has one built in and we've found that a much more reliable sensor for room entry than a simple contact closure. We like that a lot. Lights turn on. Phone rings.

http://cainetworks.com/products/webcontrol/webcontrol-faq.html

I bought a few of these as they were cheap for my home automation setup. You can find some on ebay at 50$ (+15$ of you want a case). The DS18S20 or DS18B20 temperature sensors (up to 8 can be connected) can be bought on many online stores or directly from maxim.

It has a basic web interface, email capability and can even do a little control via its 8 digital I/O (start a fan/buzzer if temperature is over xxDeg).

A flexible solution if you can do a little electronics.

Heh.. I'm presenting a tutorial at this year's Linux Symposium on controlling stuff over USB. And one of the demonstration projects is a temperature probe (I2C over USB).

I had dismissed the AKCP products because I absolutely hate companies that won't tell you how much their products cost.

What are you paying for it, if you don't mind me asking.

Will you post the slides afterwards?

I don't at all. Euro 700, with one temp sensor as a starting configuration. The reason why I am going with the probe 8 is that we are planning to expand it and we'll need more ports. I am sure you can find it cheaper in the US.