Since I still have some work to go to have my sensors and everything working fully, I thought I’d talk a little about some of my later plans, particularly automatic watering.

As I’ve said previously, my current greenhouse automation will turn the heater on when it gets too cold, but that’s it. Now that’s very useful and saves a lot of electricity over me having to go out there and turn it on and off when it needs to be done. To accomplish this, I have a power switch tail hooked up to my system that basically is a switch that switches 110 volts with only 3v. This is a pretty simple device to use, you plug one end into a socket (I use an extension cord), then plug the device into the other end. Next, you plug some wires from your micro controller (or in my case your micro computer) into the power and ground in the power switch tail.

Since I am able to control 110v devices with this device I can control a pump to move water from one place to another. So, my plan is to place a electric pump in a rain barrel and turn it on when the moisture level in the planters indicates that the soil is dry. I’ll hook the pump up to a drip system that will drip on all the trees.

This is the rain barrel and pump I plan on getting to accomplish this. I should be able to get both for maybe a little over $100. The one thing I kind of worry about is that the rain barrel only holds around 50 gallons and the pump will pump around 20 gallons per minute. I have to find out if there is a way I can tone it down a bit.

The other thing I have thought about is not wanting the pump to run when there is no water in the barrel. To do this I can use this float switch. When the water is below a certain level in the barrel I will set the code to not turn the pump on. I’ll have to drill a hole in the barrel to install it, but it should be easy to attach it to the ADC to determine if the switch is open or closed. I plan on running the program every 5 minutes to do all the logging and checking of the sensors.