Please note that there's a Git repo for code at:
If you'd like the latest fixes or would like to contribute. Thanks Jonny Ervine!
I had some issues with Kingston SD Cards, but the SanDisk cards I'm using now have run for weeks without issues, so I'm changing the parts list to reflect that.
Also, after some 49 days, 16 hours, the display flatlines, as the reading routines start returning the same number over and over again. A reboot clears it, so just reboot once a month until I figure out what's up.
Over the past summer, my vacation home had a small water leak for three months, and I realized that had I been measuring the humidity in the effected area, I'd have
seen it go to 100% for a long time and I could have dispatched someone to fix the small problem before it became a big one.
And since I've been playing with Raspberry Pi computers for a while now, and saw an inexpensive temperature/humidity sensor on AdaFruit, I had all the pieces I needed
to implement an inexpensive network-connected monitor.
The Bill Of Materials (BOM):
1) Raspberry Pi Model B
3) SD Card
4) Temperature/Humidity sensor
5 ) Power Supply (I use PoE splitters, but any 5V 1A Micro-USB supply will work)
I used the following exact parts, but obvious substitutions can be made to match local conditions and the state of your junk box. Shipping and the availability of bundles
may effect your final price.
$35.00 RPi http://www.newark.com/raspberry-pi/raspbrry-modb-...
$ 8.12 Case http://thepihut.com/products/classic-raspberry-pi... (5.99 Euros)
$ 6.99 SD Card (Sandisk, not Kingston)
$15.00 Sensor http://www.adafruit.com/products/393
$15.99 PoE Splitter http://www.newegg.com/Product/Product.aspx?Item=N...
And a few other miscellaneous things like hand tools, soldering iron, hot melt glue gun, small pieces of plastic wood, etc.