Homebrew Temperature Monitor/Controller
Latest News
Version 2 of the controller is done. It's smaller, better,
faster, cheaper, and easier than the original.
The new controller is based on the Arduino board, which can be picked up for about $30. In another cost
saving move, I am now using the probes from the Maverick ET-73 temperature sensor. These are simple
thermisters and all the trouble of dealing with thermocouples is gone.
A wireless internet option is also available for the controller. You can connect to the controller with your
web browser to get information as well as change settings.
I just put this site up real quick - there will be more information soon.
The old version of the controller can still be found here.
Forum Discussion
There is a very long but very informative thread on The Virtual Weber Bulletin Board web site that
talks about other things people are doing with this controller. It is a long read, but I
highly suggest checking it out here.
Details
The hardware is very small, easy to work with, and modular. The Arduino has a concept of "shields" or stackable
modules that fit one on top of the other. I bought an off the shelf Arduino USB board from SparkFun:

Added a wireless ethernet shield from AsyncLabs on to that:

And build my circuit on an Arduino proto-board:

Plug them all together and you get the final system:

Parts List
The bare minimum would be the arduino, parts from the schematic, probes, and a blower. You could probably build it for around $50 if you
already have the probes. However, the LCD display is practically a requirement, especially if you don't ad the WiShield ethernet shield.
- Arduino Duemilanove - SparkFun $30
- (Optional) WiShield - Async Labs $55
- (Optional) ProtoShield - SparkFun $17
- (Optional) LCD DIsplay - SparkFun $17
- Resistors - 2*22K, 1*1K - Radio Shack $2
- Diode - Radio Shack $1
- Power transistor (IRF-510 family) - Radio Shack $1
- 12V DC blower - DigiKey part #P12902-ND $12
- Maverick ET-73 Probes - use your own, or buy replacements from Maverick Industries
There's actually a schematic this time - and it is quite simple:

Source code for the sketch (it is still rough, but it will get you going) is located here.
Feel free to contact me at
bbqcontroller@gmail.com I will
keep up as best as I can, at least until all the spammers get the address.