Solar Tracker

[kenemon 29]

Has anyone had any experience with solar trackers. There is mucho to find on the web using analog designs.

After an extensive search, I found this. After I built it and burnt my fingers a couple times, it seemed like the control could easily be made using the uC instead with PWM motor control.

 

 

I like the sensor idea here, reverse some clear green LEDs. cheap and practical, guess its time to work on some good adc code for the LP....

 

Lots of info here:http://www.redrok.com/main.htm

[zeke 693]

You should tell everyone about the simulator program you are using there.

 

I'm sure they would love to know about that sweet little program from Linear.

 

:think: And post up your asc file too. :thumbup:

[kenemon 29]

I'm sorry zeke but the simulator wasn't my idea. True credit to the author on the pic. The simulator result was, of course, why i picked this design from all the others out there. It is the most stable of the bunch, and it will not waste valuable energy oscillating around the light source. It is my hope this strategy can be implemented within the msp code using timing and the WDT.

 

if anyone is interested in the simulator, please see: http://www.linear.com/designtools/software/#LTspice

[kenemon 29]

I decided to try out the sample Maxim development board that just arrived.

 

In the application I am pondering here, I wanted to evaluate the signals that the LED sensors will generate.

Using a LED to provide the signal is not a new idea, but is so to me :shock:

Maybe one of you can help me interpret the results, and the implications for importing this sensor modality into the MSP430???

The MAXIM scope is a little confusing to me......

 

I hooked up the ADC and a basic breadboard circuit to the MAXIM board, and loaded their software...

 

I then captured some scans neutral, and then with flashlight applied.

 

I then reversed the polarity of the LED to see it's effect. WIthout, and then with light applied.

[rockets4kids 204]

Here are some app notes that will help you with using photodiodes (which includes standard LEDs)

 

http://vorlon.case.edu/~flm/eecs245/Dat ... evices.pdf

 

http://sales.hamamatsu.com/assets/appli ... 043e07.pdf

 

Enjoy!

[kenemon 29]

Thanks Peter. Good to see you here, lots of good peeps who chip in...

 

I did enjoy those documents you linked. I am interested in using fig 7 on the sharp circuits. My inexperience leaves me doubting i could guess the values of the components, can you help me calculate the values needed?

 

KB

[kenemon 29]

Finally managed to get the 2-axis light sensor together.....

 

 

Next step wire up MOSFETs and LP for signal processing

[kenemon 29]

[kenemon 29]

Some Progress:

 

(not currently tracking )

 

next: adding limit switches

[bluehash 1,581]

Did you fab that?

Looks neat and clean.

[kenemon 29]

Thanks Blue,

 

Using a DirectTV antennae azimuth mount as a base, i was able to dissect it and add some bearings. The horizontal mount uses some aluminum disks which i had to cut in 1/2" milling stock with a 6" hole saw (scary!) on a drill press. Using lazy susan bearing there. The gears and belt were commercially available. Cost so far (less solar panel) about $75. Struggling now with the code for the sensor using MSP w/ PWM output to control TI motor drivers.

 

KB