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Suggestion for a project - solar tracker


I want to throw out a project idea I have had for a a long time. I am interested in any feedback you have to offer.

I am very interested in creating a DIY solar tracker and making the plans freely available to anyone who wants them.

A solar tracker essentially determines where the sun is in the sky and then drives actuators to point something at the sun - presumably solar panels or mirrors but perhaps also an Illudium PU-36 Explosive Space Modulator.

I have seen DIY analog electronic projects that use two pair of light sensing diodes. A pair of diodes on each of two axis determines which direction is brighter and drives the actuators to move the whole assembly. This is generally accurate with the exception of extreme overcast weather and nighttime. I assume that it would be really easy to reproduce a more intelligent version of this using a FEZ and some sensors.

The other idea that I think would be a lot more fun would be to use a GPS to determine lat, long and time of day. From these variables you can do the math to figure out where in the sky the sun should be. Unfortunately I am too new to the concept of sensors to even know what is available. I assume that there is some sort of compass sensor, correct?

I have tried for a long time to create a .NET library that is able to do the solar calculations but they are based on some crazy math and Julian dates - stuff that is a wee bit beyond my intellect - and all of the examples I can find are written either as mathematical formulas or in javascript, perl, etc and my translations to C# have not yielded correct results. I’ve also found that I get wildly different results when using math functions in the NETMF than with the full .NET Framework.

Frankly I am just blown away that this kind of project has not been done yet (that I can tell) and that the solar calculation code is not abundantly available.

Anyway, I am just throwing this idea out there to see if there is any interest or suggestions.


You can do this the easy way…have few light sensors like this one, sold here,

Not you can see what sensor gets the most light and through that you can determine the most sun exposure.

If you know little electronics, then you do not need to spend money on the component board, you can just use photoresistor


If your plans are for permanently mounted solar panels then I would go for a mathematical approach rather than having the actuators spinning back and forth to find the sun using some light transistors.
Even a GPS would be an overkill for this project and the coordinates taken from say google earth would be more than sufficient.
What you would need is a RTC (Real time clock) like there is in the Domino or a external chip like the DS1307. So that your system is easily restarted if you have to reboot the FEZ.


Amatuer radio has what you need!

The satellite antenna trackers will also very accurately track celestial bodies. The Keplerian Elements necessary to do the calculations are available off the Internet or there are software packages that do it all for < $100 ( All you need is the Google Earth latitude and longitude and the direction of North at your location. After that, you can correct the elements as desired or the software will update as often as desired.

The mechanical drives are reasonably priced and can handle fairly large loads. You could model a FEZ controller on one of the many software packages available.




I am working on such a device: “Illudium PU-36 Explosive Space Modulator”, kidding of course, the SPA (Solar Positioning Algorithm) is still in the EMX - RLP phase on the FEZ cobra.

So if your are interested we might be able to work together.