There are a number of components necessary to do remote temperature monitoring of a smoker with computer logging. Most of these require choices to be made. This is by no means a comprehensive list of all possible options, but here is what I have so far.
There are a few assumptions I have been making. First, the goal of the project should be for "open source" style hardware and software. The finished product should be something that a wide variety of people could build using as many off-the-shelf components as possible. Second, the product cost is crucial. A $1500 temperature monitor is probably of little use. Third, I want/require/need the ability to go to sleep and have the system "wake me up" when temps are out of control. I use my Mavrick now, but I really don't like the fact that the units can get "out of sync" and no alarm goes off. (this last part should be the easiest part of the whole operation however)
1) Thermometers. This is by far the easiest component to source. A variety of sensors is desirable. The temperature range needs to be in smoker and meat ranges, and this seems fairly easy to source. There are MANY sources for thermometers. The final product would have to pick a few that work with the device and provide model numbers.
2) DAC. This by far is the costliest part of the operation. You will require a Data ACquisition device to convert thermometer readings into signals that your computer can understand. There are a variety of options here, ranging in price A LOT. Here are some examples:
RS-232 - relatively low cost
http://www.superlogics.com/cpseries.asp
USB or Ethernet - Cost is going up significantly here (note: many of the USB ones that you will find are actually the labjack relabeled)
http://www.dataq.com/products/startkit/di158.htm
http://www.labjack.com/labjack_u12.html
There are many, many DAC options out there.
There are two problems with these DACs. a) Cost. Many are expensive and start at the $100 range. b) Wireless. How do you make them "wireless"?
3) So, assuming you go with a DAC and want to make it wireless, here are some options.
3a) Build your own. Actually, although this sounds hard, it may be a decent way to go. The design would only need to be done once, and then it is a "buy parts and solder" operation. You could take advantage of simple unlicensed bands to do the transmission. Range could be a limiting factor here.
3b) Wireless addons:
http://www.aircable.net/AIRcable/AboutUs.html Downsides are cost and it may not actually work for these applications depending on the DAC used.
3c) The "Dell Axim" solution. Actually, this idea is not specific to the Axim, but that is what I was looking at when the idea hit me. The concept is this. Why solve the wireless problem. A "Dell Axim" palmtop computer has 802.11b built in. You could put this handheld next to your smoker, hook your DAC up to it (To Be Determined, but I think USB should be possible) and write your software to work on the handheld. Let it post information back to your home network. This has dual benefit because it gives you a very nice "Local" temperature display. The only real downside here (besides cost) is that you would need to design a "weatherproof" enclosure for your Axim (rain, snow, etc).
3d) X10. I really haven't explored this. But rather than wireless, you could use a hard wired X10 interface to use your power lines as your transmission medium. This may be the CHEAPEST solution to the problem.
3e) Infrared. Wireless, but requires line of sight. IR transmitters and receivers are VERY cheap to make. Still requires a local controller to go outside, but a reciever can work on any standard computer.
3f) Cheat. Hard wire it. Distance is a big problem here though. Most DAC's aren't going to work well over a long distance.
Summary of Wireless section. a) Cost is a big issue here as well. b) Some of these solutions might allow you to perform local "control" funcitons as well (ie: 2 way communications). Why? You could emulate BBQ-Guru style control of your smoker.
4) Software - This is the area I know the most about. All things being equal, this is not a difficult area to deal with. Writing interface code for whatever DAC/Wireless solution is implemented on whatever platform is chosen (palm computer vs. full-blown pc) should be fairly straightforward. Nothing here is "inventing the wheel" as it were.
That's as far as I have gotten so far. I think the X10 solution deserves far more time than I have given it so far. It has the most promise to be the CHEAPEST solution out there.
-Matt
