USB Freeduino (Arduino-clone) $ 22.50
Adafruit Data logging shield $19.50http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=243
SD Card $ 6
Aluminum NoTrespassing Sign $ 2
Potentiometer 6639S-1-103-ND $12 (Digikey)
2 2”x 1/2” Mending plates $ 1
100ft Ethernet Cat5 cable $ 8 (Amazon)
2 Ethernet Couplers $1.40 (ebay.com)
Prices US dollars March 2011
Any USB Arduino should work but it is easier to wire it up to an Arduino shield so the clone would have to be shield compatible. There are some good deals on ebay for Arduino Duemilanove 2009 for about $18.
So why did I add the Adafruit Data Logging Shield, you may ask? Well, if I want to collect long term weather data say overnight, then I have to leave my computer on. With the data logger, I can record the data to an SD card and don’t have to keep the computer on all night.
The potentiometer is special in that it’s called continuous turn. Most potentiometers rotate about 350 degrees and stop. Those wouldn’t work for a weather vane. This one will keep rotating no matter what direction the wind comes from.