HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Blogs
Gadget Freak
Gadget Freak Case #217: Finding the Sun With a Microcontroller
6/22/2012

< Previous   Image 2 of 2   

This multiplexing project can be modified by adding output routines to the program to drive motors or other devices.
This multiplexing project can be modified by adding output routines
to the program to drive motors or other devices.

< Previous   Image 2 of 2   

Return to Article

View Comments: Newest First|Oldest First|Threaded View
<<  <  Page 5/6  >  >>
Droid
User Rank
Platinum
Has the sun gone wobbly?
Droid   6/25/2012 9:47:10 AM
NO RATINGS
This is really cool. However, since when did the position of the sun become unpredictable requiring us to "find" it. By the way - you could also look up "fearlessthinker" on youtube.  He has built a similar sun tracker.

j-allen
User Rank
Gold
Solar tracker
j-allen   6/25/2012 9:25:31 AM
This is indeed a clever solution to a non-problem.   We would really need it if  the sun behaved like an aerobatic airplane.  In actuality it "moves across the sky" at a reliable 15 deg/hour, so a simple clockwork or synchronous-motor heliostat is perfectly adequate.  Even if there were a small aiming error, the derivative of the cosine is very weak in the vicinity of 0 deg, so your solar panels would still produce full output. 

notarboca
User Rank
Gold
Source Code
notarboca   6/24/2012 10:33:54 PM
NO RATINGS
Jerald, your project is wonderful and stimulating on a number of levels.  It is simple and elegant, from the design, to the selection of microcontroller for your purpose, to your use of multiplexing.  Perhaps I have missed something, but is source code available for this project?

Thank you so much for sharing this excellent design.

mrdon
User Rank
Gold
Re: Great Project
mrdon   6/23/2012 3:28:07 PM
NO RATINGS
Nancy, Microchip provides a variety of cool PIC micrcontrollers and tons of great app notes and source code examples. I've used them in several projects and the ease in which to get them running is truly amazing. This project is just one of several examples of how microcontroller technology can easily be implemented. Great project idea!

78RPM
User Rank
Gold
Re: Today's method?
78RPM   6/22/2012 5:41:29 PM
NO RATINGS
Charles,

Your question is exactly the one I asked when I started the project.

Their methods are probably proprietary but I believe most of them would use the brute force method of calculating the sun's position. If one searches for solar position calculations, one finds that the calculation is far from simple.  While C code is available free online, it would take a microcontroller that supports a multiple precision instruction set, an input of latitude/longitude, current time, real time clock, look-up trig tables, etc.  While my approach is not purely minimalist, I wanted my device to just look up and say, "Where's the sun?"

Jerald C

Nancy Golden
User Rank
Platinum
Great Project
Nancy Golden   6/22/2012 5:19:32 PM
NO RATINGS
I think this is a great project - very useful for efficient collection of solar energy! I particularly like PICs for these types of projects - they are so versatile and just plain fun. The inexpensive programmers that Microchip sells don't break the bank either and their MPLAB IDE is free and very user friendly. Great job!

Charles Murray
User Rank
Blogger
Today's method?
Charles Murray   6/22/2012 5:12:11 PM
NO RATINGS
Jerald: What method (prior to yours) have solar panels used to find the sun?

78RPM
User Rank
Gold
Re: Placement is everything
78RPM   6/22/2012 2:03:41 PM
NO RATINGS
Thanks, Beth, I'm working on documenting my work with directing a motor to do the output portion of this project.  For now, I hope others see its usefulness as an input device to multiplex many inputs to a single pin. -- Jerald C

78RPM
User Rank
Gold
Re: Placement is everything
78RPM   6/22/2012 1:59:30 PM
NO RATINGS
Yes, Naperlou, I tried using two photocells to find the brighter direction right/left. The trouble was that after the motor and photocells turned, they now found another decision -- go right or left.  The motor turned erratically.  I looked at charts of the sun's path and found that 110 degrees of east/west scan would be a useful range of solar energy for any latitude up to 49 degrees.  30 samples gives us 3.67 degrees of precision, so the the microcontroller could go to sleep for 3 minutes between scans. -- Jerald C

naperlou
User Rank
Blogger
Re: Placement is everything
naperlou   6/22/2012 8:05:20 AM
NO RATINGS
This could also be used for tanning.  Either instructions could be given to the user, or a movable platform could be moved automatically.  The microcontroller could allow one to add an audible roll over tone. 

All kidding aside, it is interesting that Jerald found he had to use so many photo transistors, and that he had experimented to find the result.  Good work.

<<  <  Page 5/6  >  >>
Partner Zone
More Blogs from Gadget Freak
This Gadget Freak review looks at a cooler that is essentially a party on wheels with a built-in blender, Bluetooth speaker, and USB charger. We also look at a sustainable, rotating wireless smartphone charger.
There is still time to get in your gadgets for the Design News and Allied Electronics second annual Gadget Freak of the Year contest. The top three gadgeteers will be awarded a total of $10,000.
This Hollywood movie-style gag bomb doubles as an alarm clock and a countdown timer.
Marin Davide created a prototype of a moving biped using a shape memory alloy that works like a real muscle to move a cardboard leg.
You can put this thermometer anywhere with WiFi and collect data for months to years on a single battery, depending on how often you check the temperature.
Design News Webinar Series
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
5/13/2014 10:00 a.m. California / 1:00 p.m. New York / 6:00 p.m. London
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Aug 4 - 8, Introduction to Linux Device Drivers
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: August 12 - 14
Sponsored by igus
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service