Web Based Thermometer?

brauhausjoe · 11-07-2007, 12:56 AM

Anyone made a web enabled thermometer? I have been looking around and so far I have found these:
http://www.lancos.com/webtherm.html
http://www.instructables.com/id/SD8ZT3SF1A4XWKO/
http://zedomax.com/blog/2007/05/07/diy-hack-build-your-own-altoids-digital-thermometer/

I was wondering if anyone has any other ideas or has done it them selfs? I would like to make it as economic as I can

brett · 11-07-2007, 01:15 AM

Simple question: Why?

brauhausjoe · 11-07-2007, 01:32 AM

If I can do it without much cost, I could put the temperatures on a web site and monitor when I am on the road, which for now is quite often. If temps go up when I am on the road, I can send an alert and get it fixed.

Not only that, it would be cool.

**CodeRage** · 11-07-2007, 02:40 AM

I've done all kinds of IO over the web but not anything DIY. I would recomend the first one since it appears to be the simplist and and the cheapest. You would only need one DS1621 any ways and could expand it fairly easy.

brauhausjoe · 11-07-2007, 03:06 AM

Thanks, that is what I am thinking too. I found this http://www.instructables.com/id/Temperature-sensor-%2f-weatherstation/ I think I'll try to use it as the sensor.

Spearo · 11-07-2007, 04:25 PM

I would think that after all is said an done. You would be better off buying an ethernet controller or PLC that has analog inputs and use a thermocouple or RTD input to the controller. I would question the accuracy of a DIY thermometer. Not all electronic components have the same tolerances. You might want to look at X10 or maybe some industrial PLC stuff at automationdirect.com.

brauhausjoe · 11-07-2007, 06:13 PM

I might end up going that route, but I would like to try it myself first. (I am one of those learn by doing guys)

I'll run some tests on the accuracy and post them here when I am done. I would think that if I am within 2 or so degrees, I should be good. I also already have most of the stuff I need at the house.

**CodeRage** · 11-08-2007, 03:57 AM

Check out the LM34. Super accurate and easy to interface. Thats what I use for everything temp wise. Hook it up to an A2D and bit bang it with a parallel port or put a micro in there to get it on a serial port and you're golden..

Buying a PLC to read it is just way overkill unless you can find something on the super cheap. I am thinking a Basic PIC kit from radio shack is more than adequate to get what you need done. If you are condfident with electronics order it directly from microchip.com. Hell you can probably get them to sample you one.

brauhausjoe · 11-08-2007, 01:07 PM

Sweet! and cheap, I already went and picked this stuff up:

Parts List:

PC Board Terminals 4@$2.49 $0.62ea Radio Shack
Resistor 1,5 kOhm 5@$0.99 $0.20ea Radio Shack
D-sub 9 female connector 1@$1.99 $1.99ea Radio Shack
circuit board 6x8” 1@$4.49 $4.49ea Radio Shack
Dallas Semiconductor
DS18S20 Temp Sensor 3@$15.12 $5.04ea www.newark.com
Schottky Diode (1N5818) 5@$0.35 $0.07ea www.newark.com
Zener Diode 6.2V (1N5234) 5@$0.24 $0.05ea www.newark.com
Zener Diode 3.9V (1N5228) 5@$0.24 $0.05ea www.newark.com

Soooooo....One thermometer would cost: $12.71 for hardware, my total cost for hardware was $25.91, I bought spares just in case I screwed something up. The software and Operating System (Linux) are free. I have an old PC laying around, and I might have a laptop if I can fix it.

The Dallas sensor is kind of pricey; I will defiantly try Virtuous's LM34 out next time. From a quick glance, looks like I might be able to simply replace the DS18S20 Temp Sensor? This is what I will be basing mine from: http://pihost.us/~stacato/digitemp/

The stuff I ordered will be here tomorrow,

Thanks for the ideas!

dinks · 11-08-2007, 07:37 PM

Here is the expensive way to do it.
http://www.nagios.org/products/environmental/esensors/em01b.php

Could always setup a webcam and point it at a thermometer.