Thursday, September 30, 2010

Sweet CLT


Cool evening tonight complete with sun-showers.  Even saw a rainbow over the BOA building.

Wednesday, September 15, 2010

Another Arduino Plant Watering System

Since my previous plant watering system was much too complex (using wifi, ftp, a hacked cell phone, and power line communication) I decided on a bit more low-level technique:  home built sensors and the Arduino platform.

In comparison this method is:
  • Reliable.  If there is a power outage watering will begin again upon power return.
  • Equipment is safer.  The water level must test positive before the pump is cycled on, preserving pump life.
  • Intelligent.  Software modifiable instruction.
  • Independent.  Isolated system is not affected by remote issues.
  • Much cooler.
Everything is boxed in an exterior double gang receptacle container, which I deemed appropriate considering the 110v AC involved.  The expandable sensor assortment currently contains two (2) RCA jacks to connect to a low-water-level sensor as well as a moisture sensor (placed in the pot most likely to dry out).

Since there is no water supply on my balcony, a pump is cycled on at proscribed times to supply drip irrigation lines.

If the pump runs dry it will seize, so prior to usage a low-water-level sensor is polled.  If the test fails, it will not run.  The test will be reconsidered at the next scheduled watering time.

In my current configuration, it's difficult to over-water due to the building configuration and elevation.  The Arduino is set to water everyday for five (5) minutes.  In addition to that, two (2) more times a day it will test for dryness at the most susceptible pot.  If it's below the set threshold it will water more.

There is also an alarm pin that will provide an indication of low water level, should I not be paying attention.

I'll post more specifics later on.