Open source folks are naturally lazy. Anything mundane task they can automate, they will. So what does an open source developer do when faced with planning, planting, and tediously watering a garden? Automate! Lazy hackers will appreciate the Garduino, an open hardware Arduino to automatically water your garden and tweet at you when your plants are thirsty. Want a frost alert on your android phone so you know to cover your precious tomato starts? How about a tool that tells you when to start seeds, when plants will be harvested, and whether you’re going to have too much lettuce in July? (Automatic seed planter not included.) Come discover open source tools for all types of garden hackers.

1. Growing Food
with Open Source
OSCON 2011
Sarah Sharp
@sarahsharp

2. Hello!

3. ✔ Linux Kernel hacker

4. ✔ Gardener

5. I'm still a lazy hacker

6. github.com/sarahsharp/GardenGeek

7. Problem #1: Scheduling

16. Garden Calendar tool
● 904 lines of C
● Object oriented representation of plants
● Takes a CSV file for input
● 11 magic fields
● not all are required
oregon spring tomatoes,1,7,3,2010-04-13,0,75,.80,6,14,0

17. Garden Calendar tool: Phase I
● Started Feb 21, 2010
● Plain text output on Mar 7, 2010

18. Issues with Phase I
● Worked pretty well
● Seed germination
rates are optimistic!
● Often forgotten
● No integration with
other calendaring
tools

19. Garden Calendar tool: Phase II
● Goal: output iCalendar and integrate with
google calendar.
● Issues: RFC 2445

21. Issues with Phase II
● Google calendar update lag
● Really should be a todo list
● Integration with Remember The Milk?
● Need an easy way to defer tasks
● Web front end?
● Storage for users

22. Problem #2: Frost

23. How Frost Works

24. How Gardeners deal with frost

25. Dealing with Spring Weather:
“Cold Snaps”
Data Source: WunderGround.com,
Portland, Oregon, USA,
April 2010

26. Lazy Hacker: Polling vs. Interrupts

27. Search for the Perfect Android App
● Need an alert for frosts
● Alert must be timely
● Nice: open source app
Weather Checker

28. Search for the Perfect Android App
● Need an alert for frosts
● Alert must be timely
● Nice: open source app
Weather Checker
● Alerts too often
● Alerts at the wrong time
● “average” temperature?

29. DIY

31. “You may not use the Wunderground
Data Feed for use in a mobile
application for mass distribution, even if
there is no monetary cost for the mobile
application.”

32. Open Government Data
● NOAA weather data
● No history, only future predictions
● Only for the United States
● SOAP interface that returns XML

33. Garden Weather Alert

34. Garden Weather Alert TODO
● Add a background task for alerts
● Alert on hail, wind, extreme heat
● Use GPS coordinates
● Support international locations
● Options for °F vs. °C

35. Automatic Watering
with Arduinos

36. Garduino: Gardening + Arduino
● Automatically
waters your plants
based on soil
moisture
● Good tutorial on
instructables.com
http://www.instructables.com/id/Garduino-Gardening-Arduino/

37. Soil Moisture Sensor
http://www.cheapvegetablegardener.com/2009/11/how
-to-make-cheap-soil-moisture-sensor-2.html

38. Soil Moisture Sensor Science
V=I*R
R = infinite ohms R is finite
I = 0 amps I > 0 amps
V = 0 volts V > 0 volts

39. Garduino Step 1:
Build Soil Moisture Sensors

40. Garduino Step 2:
Hello Blinky LEDs

41. Garduino Step 2:
Hello Blinky LEDs

42. Garduino Step 2:
Hello Blinky LEDs

43. Garduino Step 3:
Hello digital output

44. Garduino Step 4:
Set up watering system

45. Garduino Step 4:
Set up watering system
http://powerswitchtail.com/

46. Garduino Step 5:
Calibrate System
● Soil moisture sensor takes a while to react
● Need Arduino code to:
● Limit how often the pump runs
● Don't water more often than N seconds
● Issues:
● No RTC on the Arduino
● Use milliseconds from start
● ~80 lines of code (with detailed comments)

47. Final Garduino
Arduino wall
power
soil power
moisture tail
sensor switch

48. Garduino
Demo

49. What's next?
● Wireless communication
● JeeNodes - $22 kit
● Finish irrigation system

50. Want get involved?
● http://www.gardengeek.org
● http://github.org/sarahsharp/GardenGeek
● Twitter/Identica: @gardengeekery

51. Thank you!