Gugaplexing LEDs ???

[Mike - K8LH]

Just came across a relatively new concept called Gugaplexing (sorry no references) which can drive twice as many LEDs as Charlieplexing...

Charlieplexing allows us drive any unique LED in a matrix by setting two pins lo/hi. Gugaplexing uses a handful of transistors as tri-state invertors and allows us to drive additional unique LEDs in a matrix by setting two pins hi/hi or lo/lo. As with Charlieplexing, all other pins will be tri-stated.

Refer to the crude drawing below and work through the signal paths to see which LEDs are turned on when you make any two pins lo/hi, lo/lo, or hi/hi to see how it works. The columns labeled NOTP1, NOTP2, NOTP3, and NOTP4 are driven by the tri-state invertors. I use the blue lines to indicate "lo" and the red lines to indicate "hi" and I move them around the matrix drawing to help me visualize the signal paths.

A see a couple negatives with this method; (1) It requires additional circuitry, and (2) Where I've shown how we can drive a column full of LEDs at one time in a Charlieplexed matrix (with nice even brightness), the Gugaplex decoding only allows us to drive one LED at a time so duty cycles and brightness could be dramatically lower.

All in all, a very interesting concept.

Mike

ps: disregard LED numbers in drawing. they're just left over from some other drawing...

 

[binzer]

Just came across a relatively new concept called Gugaplexing (sorry no references) which can drive twice as many LEDs as Charlieplexing...

All in all, a very interesting concept.

Mike

This looks similar to keypad xy type scanning, only driving leds.
Mike

 

[ericgibbs]

hi Mike, [K8LH]
As you say, the down side is the extra hardware and board area.

I think I would go the charlieplex route in a design and if that couldn't cut it, I would most likely goto to a PIC with a higher pin count.

To me gugaplexing sounds a bit too complex in its complexity when compared to the multplexing of charlieplexing and just increases the complexity of the program.

 

[AllVol]

hi Mike, [K8LH]
To me gugaplexing sounds a bit too complex in its complexity when compared to the multplexing of charlieplexing and just increases the complexity of the program.

That's perplexing.

 

[ericgibbs]

That's perplexing.

Me too.!

Youv'e been quite for while, until just recently, hope all is well.

 

[AllVol]

Me too.!

Youv'e been quite for while, until just recently, hope all is well.

Just fine now, thank you. Had a bout with pneumonia back in the winter that took its toll for a while.

Just got a PICkit2 system for my big 70 birthday a couple of weeks ago, and have been learning assembly with it. I was using PICaxe for its simplicity, but felt challenged by the "exotic" language.

Learning assembly is easy. Learning M-sPasm proves more difficult.

Hope all is well with you and yours.

G'luck

 

[ericgibbs]

Just fine now, thank you. Had a bout with pneumonia back in the winter that took its toll for a while.

Just got a PICkit2 system for my big 70 birthday a couple of weeks ago, and have been learning assembly with it. I was using PICaxe for its simplicity, but felt challenged by the "exotic" language.

Learning assembly is easy. Learning M-sPasm proves more difficult.

Hope all is well with you and yours.

G'luck

hi,
Now you are studying programming, looking foward to seeing your first Gugaplexing program.!

In the UK over a certain age we get a free pneumonia shot, lasts about 10 years, also a free, annual 'flu' jab

Probably like you, I roll back the bed sheets each morning and think 'I'm still here'...

Regards

 

[Mike - K8LH]

hi Mike, [K8LH]
As you say, the down side is the extra hardware and board area.

I think I would go the charlieplex route in a design and if that couldn't cut it, I would most likely goto to a PIC with a higher pin count.

To me gugaplexing sounds a bit too complex in its complexity when compared to the multplexing of charlieplexing and just increases the complexity of the program.

Reference; Gugaplexed Instructable

Definately some disadvantages but I suspect there are situations where this method might come in handy.

The article author uses a pair of 40 element arrays which contain the data direction register and output port register patterns to drive each individual LED in the matrix. I'd like to see if I could modify the matrix layout to simplify the transistor driver scheme and reduce the array handling overhead in the software driver.

Mike

 

[AllVol]

hi,
Now you are studying programming, looking foward to seeing your first Gugaplexing program.!



In the UK over a certain age we get a free pneumonia shot, lasts about 10 years, also a free, annual 'flu' jab


Probably like you, I roll back the bed sheets each morning and think 'I'm still here'...

I usually check the obituaries in the morning paper before taking any chances. LOL!

Regards

Not that far along, yet. I have successfully programmed a light sensor and a temperature sensor. Soon I will get into the perplexing plexination of LEDs.

Yeah, we have them too. I was in line for the 'monia and flu a few years back. At my turn, the nurse said I would be getting the last 'monia shot. Behind me was an elderly gentleman, looked like he was on his last legs. I passed on mine so he could have it. He's probably dead now, and I got pneumonia. Life's a bar-room beauty queen, ain't it?

I usually check the obituaries in the morning paper before taking any chances! LOL


You too.