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 2/6  >  >>
radioman63
User Rank
Iron
Re: Bob Pease must be rolling in his grave.
radioman63   8/27/2012 11:04:50 AM
NO RATINGS
Yes!  I remember reading that article 30 years ago.  Would you be able to point me towards a copy of it?  Thanks.

mrdon
User Rank
Gold
Re: Any Analog Solutions?
mrdon   7/22/2012 9:34:50 PM
NO RATINGS
The motors were probably driven by discrete or IC based H-Bridge circuits. These circuits are commonly used to provide directional control for motors.

mrdon
User Rank
Gold
Re: Bob Pease must be rolling in his grave.
mrdon   7/22/2012 9:22:00 PM
NO RATINGS
I remembered Forrest Mims describing his solar tracking device in the defunct Science Probe Magazine. It consisted of an analog circuit driving a dc motor. The detectors for the circuit were solar cells attached to the dc motor. Based on the sun's position,  the motor will point the solar cells in the direction of the sunlight. As explained and demonstrated in this project, a small microcontroller can enhance the performance of such a basic sun tracking device. Cool project!!

charly5139
User Rank
Iron
Re: Bob Pease must be rolling in his grave.
charly5139   7/22/2012 5:04:59 PM
NO RATINGS
Here in Europe, I would choose a microcontroller with a built-in RTC (real-time-clock). Knowing time and date, I can predict when the sun appears on the horizon, the elevation and when it disappears again in the evening. On cloudy, rainy days it might be useful not to switch on the servos. However, if the sun shows some erratic behavior which makes it necessary to follow it by an X/Y-tracker, your circuit might be better... (but I've never seen this on our planet).

Regards

Charly

Chris PE
User Rank
Gold
Re: Bob Pease must be rolling in his grave.
Chris PE   7/5/2012 1:06:56 PM
NO RATINGS
@Jerald,

I have my old design for sure. All this interference and "chatter" can be eliminated by integration and delay of a signal that is usually splendidly done by installing a capacitor in the output driving circuit.

Best Regards,

Chris

78RPM
User Rank
Gold
Re: Bob Pease must be rolling in his grave.
78RPM   7/4/2012 6:45:39 PM
NO RATINGS
Hi, Chris,

I mostly agree with you. In fact, I tried connecting four photocells to four opamp comparators. I ran the non-inverting of one into the inverting of the next one in a ring.  The binary search for right/left, up/down didn't work.  It kept getting distracted by clouds and rocks and shadows and the motors went wild like a hound dog on a scent.  If anyone has an efficient analog design, I'm interested.


But, again, I'm disappointed that everyone focuses on the solar application -- but then I guess I should have changed the title.  The circuit and program is really about multiplexing in general.  When I did aircraft flutter tests back in 1980 this little circuit would have been more powerful than the DEC PDP 11/70 we were using.

Jerald Cogswell

Rob Spiegel
User Rank
Blogger
Re: A question of efficiency
Rob Spiegel   7/3/2012 12:54:34 PM
NO RATINGS
Thanks, Mydesign. We are certainly eager to see the gadget. 

Cadman-LT
User Rank
Platinum
Re: Bob Pease must be rolling in his grave.
Cadman-LT   7/3/2012 11:31:06 AM
NO RATINGS
I thought that this had to have already been done..for the solar. As it turns out I was right.

Chris PE
User Rank
Gold
Bob Pease must be rolling in his grave.
Chris PE   7/3/2012 11:21:37 AM
NO RATINGS
I tried to understand "almighty" processors being used everywhere. From MP3 players to refrigerators and even coffee machines.Why do we love to complicate things? I agree with John E , who described a design similar to the one , that I published  (with Bob Pease blessing) about 30 years ago in Popular Electronics. Hundreds of trackers are using it and it has only 4 photo resistors and simple differential-servo system.I had tons of positive feedbacks and never heard anything negative on it , except that some people did not understand how servo works and what kind of transistors to use on an output.Sixty phototransistors?Isn't it a bit of overshoot?It would be great for navigation , but to move solar panels we do not need such a sophistication.Just my humble opinion.....I always loved analog.

Mydesign
User Rank
Platinum
Re: A question of efficiency
Mydesign   7/3/2012 4:55:58 AM
NO RATINGS
1 saves
Rob, thanks. I had gone through the source code and trying for an implementation. I will let you know within a couple of days that, whether it's working fine or not.

<<  <  Page 2/6  >  >>
Partner Zone
More Blogs from Gadget Freak
Eric Chesak created a sensor that can detect clouds, and it can also measure different sources of radiation.
This Gadget Freak Review looks at an affordable plug-and-play printer, a 3D printer that was hacked by a group of French design students to create real tattoos, and an analog camera that was built using 3D-printed and laser-cut parts.
What youíll find in this Technology Roundup is the best of the best Gadget Freak projects, as voted on by you -- our loyal readers.
We look at a wearable device that uses an adhesive electrode and headband to help reduce migraines, as well as a plug-and-play outlet cover that replaces traditional night lights.
Al Linke's animated weather display uses a Rasberry Pi to periodically pull weather conditions from the Internet and then displays a corresponding animation on an LED display.
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


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: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service