Charlieplexing with the BS2

LowIQGenius

Hey everyone, I've started a project where I'm charlieplexing 64 LED's using 9 pins on my BS2.· I wanted to start a discussion about how I should program this display.· My thought is to do a simple lookdown table with the OUTS and DIRS commands, but I wonder if there is enough space to store the entire program.· My goal is to use ONLY a BS2 (no external hardware)·to run my display because I'm broke.· I'll post a sample program as soon as I find time to write one.

Thanks in advance for the help!

Carl Hayes

Forgive my ignorance, but what is "charlieplexing"?

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· -- Carl, nn5i@arrl.net

PJAllen

Here's the easy way out -- http://en.wikipedia.org/wiki/Charlieplexing

$WMc%

We learn something everyday!.
···
Thanks for the link Mr.Allen!!!!

____________$WMc%________Merry Xmas

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The Truth is out there

Bean

IQ,
It depends on how many of the 64 LEDs need to be "ON" at any given time.
If alot of them have to appear to be on together, then the BS2 is probably not fast enough. You will get flickering.
On the other hand, if you only need 1 or 2 on at a time, then it will probably work okay.

Bean.

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LowIQGenius

The plan is to eventually store several pre-programmed·animations in an external eeprom (or something like that), so I'm guessing that about 1/2 to 3/4 of the LED's will be on at any given time.· I know that the theory of persistance of vision is 50hz, but hopefully in an animation I can go as low as 30hz or so.· Actually, one of the animations is going to simply be to light up the LED's in a random order with a slight pause in the loop to create a sparkle effect.· At roughly 4000 commands/second my hope is that each subroutine cycle only uses at most 10 lines of code, plus the animating functions.