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Topic: big multiplexing tri colour led cube - will it refresh fast enough ? (Read 3 times) previous topic - next topic

knighty

doh!  I was hoping for something I could clip the chip into, which would then happily solder into a perf board....


guess I might have to look at using different chips then :o

#16
Jan 23, 2012, 06:37 pm Last Edit: Jan 23, 2012, 06:39 pm by evanrich Reason: 1

doh... typed out a reply.... had an idea... went to google it... lost my reply :-(


Way off topic, but if you use firefox for your browser, stop what you're doing and go grab a plugin/addon called "Lazarus: Form Recovery".   I cannot tell you how many times I've been writing an email, filling out a form, posting a VERY LONG forum reply, just to have the site act up, my internet go out, get logged out.. whatever...just to find that when I can get back to the page, all my typing is gone.

Lazarus saves what you're typing, and it could be anything, a form or just a box, it's smart enough to auto save everything you type on a page.  All you have to do is right click, select Recover, and all your typing comes right back.    I highly recommend getting it to prevent loosing your replies again.

From their homepage:

Quote
Ever had one of those "oh $*#@" moments when you've finally finished filling out a long form, and hit submit only to see an error message? And when you hit the back button, the form was blank... If so, you know you need Lazarus. And if not, you have a chance to install Lazarus before disaster strikes!
My first major project (looking for people who would like to help contribute) Bluetooth Sure 32x16 LED Displays!: https://github.com/evanric

Ruffsta

#17
Jan 08, 2013, 09:41 pm Last Edit: Jan 08, 2013, 09:43 pm by Ruffsta Reason: 1
@knighty.. you were right at saying bi-color if yer only using 2 colors..

and i thought my 400 tri color led multiplexing was a huge project..

i can't seem to the exact answers to multiplex 100 tri color leds at a time that i seek.. and you want to do 13k of them?

knighty, good luck with it.. would like to see how it comes out when yer done with it!

CrossRoads

#18
Jan 08, 2013, 09:49 pm Last Edit: Jan 09, 2013, 03:23 pm by CrossRoads Reason: 1
Well, knighty hasn't posted to the forum since
February 04, 2012, 03:54:59 PM
would not hold my breath waiting for a reply!

Its certainly possible to do more complex things, but likely more processing power is needed:
http://gajitz.com/a-bit-of-light-dancing-bizarre-3d-led-curtain-display/?ref=search&utm_campaign=googimages&utm_source=images&utm_medium=other
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

fungus


I'm planning to build a really big tri colour led cube but I'm worried with so many LEDs the multiplexing will be too slow

if I use a TLC5951DAP as an led driver it will give me 24 outputs with 12 bit resolution for brightness control


I'm thinking of building a 24x24x24 cube (13,000 led's)



24x24x24 RGB LEDs is actually 41472 LEDs (24x24x24x3)

Whichever way you slice it, that's a lot of LEDs ... and a lot of input data.

It's definitely not going to work by updating LEDs individually.

Even if you only update one row of LEDs at a time you need to update it a 50kHz to get a usable frame rate (24x24x100) - simply not going to happen with an Arduino Uno at 16MHz.

The only way I can see it working is to divide it up into planes and have each plane controlled by a separate processor. That divides all your numbers by 24 and makes them sensible.

Each plane could be multiplexed in rows so your multiplexing ratio is 24:1. Each row has 72 LEDs so it could be driven with 5xTLC5940 (or whatever...), perfectly possible to do with an Arduino-class chip.

Physically supporting the LEDs as separate planes would be tricky. I suppose that's why most big cubes I've seen seem to be hung on wires - make gravity work for you, not against you.


No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

Ruffsta

#20
Jan 09, 2013, 01:21 pm Last Edit: Jan 09, 2013, 01:25 pm by Ruffsta Reason: 1


Its certainly possible to do more complex things, but likely more processing power is needed:
http://gajitz.com/a-bit-of-light-dancing-bizarre-3d-led-curtain-display/?ref=search&utm_campaign=googimages&utm_source=images&utm_medium=other


yeah i've seen that vid and this one..
http://www.youtube.com/watch?v=dVHP7Nhsn4E

that's way way beyond what i can do atm..would be cool to do.. but who am i kidding... i'll never be able to pull that off - it's not just hooking it all up, it's doing the animations that will kill the whole thing for me.. besides, i have a few smaller projects to work on atm..

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