Friday, August 17, 2012

DIY Temp/Humidity via Arduino

The motivating factor here is my garden.  I grow veggies.  Not too many but more than my family of four can possibly consume in the short time it takes for them to go from feeding us to feeding the flies.

There are ways to properly store vegetables for the long term without resorting to canning and pickling.  These were called root cellars and they naturally maintained a constant temperature and humidity.

Flash forward to the modern age.  Root cellars are gone and we have houses with concrete floors.  Agriculture science can tell us the precise temperature range at which specific varieties of fruits and veggies can be stored for 2 - 3 months, sometimes longer.

There are no shortage of articles from the agricultural extensions with directions on how to properly store squash.  One such article, http://www.ces.ncsu.edu/depts/hort/hil/hil-24-c.html, says that after the curing period butternut squash should be maintained at a temperature of approx. 50 degrees Fahrenheit.

I could build or buy a box specifically for this purpose.  But I'm storing a variety of material, squash, cucumbers  tomatoes, peppers, onions.  Each requires it's own storage conditions.  Easily achievable by storing things at the top or bottom shelf in a small room.  Also, you should not store fruits near squashes as they emit ethylene gas.

My problem:
How the heck am I supposed to know what room in my house is best suited for storing veggies?  I need environmental data.  Moreover, as environmental conditions change within my house how do I know when to opt for environmental controls?

Pre-packaged solutions are expensive:
http://www.amazon.com/Temperature-lert-TM-WIFI220-WiFi-Edition/dp/B002YKU2Q6/ref=sr_1_4?ie=UTF8&qid=1345250935&sr=8-4&keywords=Wifi+Temperature+Sensor  $300!? YUCK!  Not only is it expensive but it doesn't solve my data problem.  I need long term data to monitor graph and watch the ever changing conditions in my house.

My idea (roughly):
Get an Arduino
Solder on a temperature sensor: http://learn.adafruit.com/tmp36-temperature-sensor
Get a wifi Arduino shield: http://store.arduino.cc/ww/index.php?main_page=product_info&cPath=11_5&products_id=237
Use this example code to send the data to Google: http://www.open-electronics.org/how-send-data-from-arduino-to-google-docs-spreadsheet/

Just an idea right now but it looks possible.