Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Del on August 03, 2007, 01:16:02 PM

Title: Smooth transition for Cylon eyes?
Post by: Del on August 03, 2007, 01:16:02 PM

Hi,

I seems straight-forward to make some "Cylon eyes" that scan back and forth
using a microcontroller, but how does one make some that transition smoothly?
 ???

The following article uses capacitors, but is there a way to do this programmatically?

http://www.evilmadscientist.com/article.php/CylonOLantern

I want to minimize the parts-count (to simplify the circuit and save space).

Thanks!
 :)

Title: Re: Smooth transition for Cylon eyes?
Post by: Soeren on August 03, 2007, 08:37:39 PM

Hi,

Quote from: Del on August 03, 2007, 01:16:02 PM

[...] using a microcontroller [...] transition smoothly? [...] is there a way to do this programmatically?

Sure, with a ?controller it's easy, just PWM the LED's to attain as smooth transitions as you like.

Simplest circuit will be 1 ?ctrl'er, 8 (or what number you're planning) LED's, a resistor for each LED and a small ceramic cap over the chips supply pins - assuming you choose one ot the ?ctrl'ers that can run from an internal RC oscillator.

Title: Re: Smooth transition for Cylon eyes?
Post by: Admin on August 04, 2007, 09:14:18 AM

have you considered just buying one?
http://www.dimensionengineering.com/Sinewinder.htm

(http://www.dimensionengineering.com/images/products/Sinewinder.gif)

Title: Re: Smooth transition for Cylon eyes?
Post by: Del on August 06, 2007, 11:42:48 AM

Quote from: Soeren on August 03, 2007, 08:37:39 PM

...just PWM the LED's...

Hi,

Aren't the number of PWM ports usually limited to 1 or 2 on most microcontrollers?
How can I attach multiple LED's to these ports so that they can be addressed individually?  ???
Or, am I misunderstanding completley?  ;)

Thanks
 :)

Title: Re: Smooth transition for Cylon eyes?
Post by: Del on August 06, 2007, 11:43:42 AM

Quote from: Admin on August 04, 2007, 09:14:18 AM

...have you considered just buying one?...

But where's the fun in that?  ;)

Title: Re: Smooth transition for Cylon eyes?
Post by: Admin on August 06, 2007, 01:24:23 PM

Why buy capacitors when you can make your own with store bought chemicals? Why buy chemicals when you can make your own by mining minerals?

The same reason . . . :P

What I mean is, it really depends on what Del's goals are for the project. I only make stuff when the commercially available stuff is either too expensive or doesnt do what I want, or when I just want to learn how it works.