Friday, February 21, 2014

Gardening with the arduino post one

The Arduino is an easily programmable mircocontroller that can make a seemingly insurmountable electronics engineering feat into a completely doable project with a little circuit design and C programming know how.

From the website:
 Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists and anyone interested in creating interactive objects or environments.

This project will eventually monitor a cold frame air temperature and soil moisture.  When the air temperature gets over a threshold fans will turn on.  When the soil dries out the irrigation will be turned on.  I will also be able to log the temperature and turn on the fans or irrigation remotely through the home wifi.  The inspiration came from a Make magazine article called Garduino and an article by the same author.

Post one is about the power source.

This will be battery controlled and solar charged.

Here is the complete power setup.  The 10 watt solar panel was one of the most expensive components at $39.99.

At 12 volt 8AH battery.   This cost $32.99 at Batteries Plus.  They are normally used for home alarm systems.  They are a good choice since they are designed to be recharged and sealed for low maintenance.

This is the voltage regulator.  The battery supplies 12v but the arduino needs either a steady 5v or 9v-12v if you use the on board voltage regulator.  Since step down regulators are more efficient than the on board regulator and this project will be solar powered I invested the $7.22 to buy a step down regulator to save some power.

This is the charge controller.  At 3 amp it is more than will be needed. It also prevents over charge and night time flow back discharge.  Cost $14.90.

With some taxes in it for about $94 (free shipping!) just to power the project.  I think those fresh veggies in November will be tasty enough to justify the cost.

The next post will be about the sensors.

Solar dehydrator

It seems like all I have done for the past 10 years is work on house projects.  As I am two thirds of the way though my third house remodel I can say that I am sick of home repair.

That is a big reason why there have been no updates for so long.

Oh look, another tile job.

Wheee, more dry wall...

Lately I have started to take some time to work on garden projects again.  Last year I made raised beds and planted fruit trees.  Also made a solar dehydrator last August.  After reading about all sorts of dehydrators I went with a basic design.  The down draft variety looked interesting but I just won't have that much to dehydrate.

The collector is about 2' x 4'

It runs off of an old 5 watt panel that I had laying around.  About as simple as can be.  When the sun shines the fan spins.

Coffee can painted black.  After being in the sun for a couple of hours the shady side of the can was over 130 F.

The solar panel connects to the fan through a couple of bolts in the wall.  This make disconnecting the panel super easy.

A 120mm computer fan that I bought used.  They move over 120 CFM at full speed.  If I had known how good these fans were I would have bought all they had.  After a couple of hours in the sun with the fan going close to full speed the inside ranged from 120 F to 140 F.  Colorado is so dry that the heat is dehydrating as much as the air moving over the food.

5 screens that are about 2' x 3'.  There is room for 3 more if I ever need them.

This was one of those special projects that I did not have to buy a thing for.  Finally it payed off to have a garage full of junk.  The panels were left over house siding.  The fan and solar panel were from old projects.  The screen has been floating around my garage since the 90s.  The paint and hardware weren't as old but still had been moved at least twice.

So far I haven't dried much more than strawberries.  They turned out great but were eaten before a picture could be taken.  The plan is to dry the apple surplus to feed to chickens in the winter.