Friday, December 02, 2011

Dual temperature Logger

Oh you poor neglected blog, I really should be paying better attention to you.  Here is a project I have started to work on that I believe belongs on this blog and not really in my homelife.  I have a friend that has a unfinished crawlspace that is easily accessible (read walk in height) that I've mused about placing a barrel for aging weird beers in.  The trouble is it is unregulated temperature, and I want to have an idea of the ranges I can expect from it before I lay my precious beer down there.

I purchased a TI Launchpad a while ago, for the purpose of having a cheap and available development board to play with.  These are great at $4.30+shipping you don't need to worry about ruining them and they have the USB host for programming them built in.  It is quite a nice dev-board for the price and I know Texas Instruments is just trying to buy market share here, but if it drives down the Arduino and Phrallax devboard prices I'm all for it.  I need an experiment and want some long tail results about the temperature inside the crawlspace vs the outdoor temperature to get a feel for how stable the temperature is.  My hope is that it stays above 40°F (his furnace and hot water tank are down there so it should be above freezing) and stays below 70°F in the summer.  Below 60°F would be really ideal, but for free you can only hope for so much.

My general plan was to get two temperature probes and tweet the temps a few times a day, hack-a-day posted this little project that has me thinking that I may use WUnderground for a destination to store the data.  I could I suppose roll my own CGI script to take a post datastream and keep it in a text file, or use a wireless accessory to get things really interesting.  This will probably have to be an ongoing post because I haven't decided how I want to proceed.  I can work on interfacing directly with the network using the Devboard and a Wifi module.  That route has some benefits and runs around $50 for the wifi module.  Another route is to use a bluetooth module and interface with an Android phone to do the heavy lifting for me.  I could just log the data to the phone on an SD card, and using No-IP access a webserver to just check on it from time to time.  The beauty of using the Android device is it has built in WiFi, storage a built-in battery backup and is really pretty compact.  A final option is to use the Open ADK and plug in via the usb port.  The drawback is it was designed for Arduino boards, so I'll be inventing the wheel here to make it work with the TI board.  I'm not opposed to buying something like the IOIO, given the costs fall pretty much in line with the cost of the WiFi module, I had just hoped to pull this off with the TI boards.