self automated solar tracker

I just bought an Arduino Duemilanove, and I wanted to build a self automated solar tracker. Anyone think they can give me a few instructions on how to get started? I have an OWI 535, and 4: 1V 400mA solar panels, any way I could implement these components in to making a self automated solar tracker? IF you have previous projects like this with instructions, please feel free to email me at dmontaej@gmail.com

Have you tried a google search?

I know I can just google it, I've tried, but I enjoys others input, to vary my options

Have you tried a google search?

LMGTFY - Let Me Google That For You

Although I did find that quite funny, the whole "Have you tried google" thing is a little counter productive.....and could really be a reply to 99% of forum posts.

This looks like a well documented project with well noted code
http://arduinofun.com/blog/2009/10/21/arduino-solar-tracker/

I have seen 2 different methods to doing this. You can use a row of 2 or 3 photo resistors and check each one. With 3 it can move in either direction so that the middle photo resistor has the light center on it. With 2 you have it move in a single direction. Another method with just 2 sensors is on stays out in the open. Its purpose is to to be a reset for the system when the sun goes down. Thus telling the unit to return to the start position. The other one will have a tube around it. That way its only able to see direct sun light. If it is not receiving direct sunlight the unit turns to the west. The sun only tracks one way so the tracking sensor only needs to tell it to move in one direction.

As for the code i wouldn't know where to begin. But i hope i made some since there.

Another answer:

Bear with me... a little model would make things easier!

On the panel that must point at the sun: Mount, in the plane of the panel, 4 phototransistors, arranged in a square, about 5cm apart.

Attach two vertical "fins" at right angles to the plane of the panel and at right angles to each other, such that each phototransistor is in a "corner" of the "cross" the fins make if viewed from above.

If I've managed to descrive that, then you will see that whenever the panel isn't right, one or more of the phototransistors will be in a shadow.

But all of it isn't really necessary.

You can program the panel to point to where the sun SHOULD be. You don't need to actively "follow" it... any astronomical almanac (or re-invented junior version) will tell you where the sun will be. All you need is date and time of day.

And you don't need half of that.

The problem is in two parts.... tracking across the sky daily and "up" and "down" the sky by season.

The former: by Arduino driven timer and electro-mechanical means.

The latter by a crank you turn by hand once a month. You'll want to check the panel from time to time anyway, won't you?

Of course, active tracking would be more fun!

If you're still interested, arduino sun tracker code:

http://www.mowcius.co.uk/suntrackercode.html

Accuracy of at least 0.5deg

Mowcius[/url]