Pages: 1 [2]   Go Down
Author Topic: big multiplexing tri colour led cube - will it refresh fast enough ?  (Read 3135 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 11
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

Sunnyvale, CA
Offline Offline
Full Member
***
Karma: 0
Posts: 147
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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!
« Last Edit: January 23, 2012, 12:39:31 pm by evanrich » Logged

My first major project (looking for people who would like to help contribute) Bluetooth Sure 32x16 LED Displays!: https://github.com/evanric

Rhode Island - USA
Offline Offline
Full Member
***
Karma: 0
Posts: 156
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

@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!
« Last Edit: January 08, 2013, 03:43:58 pm by Ruffsta » Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 543
Posts: 27348
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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
« Last Edit: January 09, 2013, 09:23:01 am by CrossRoads » Logged

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.

Valencia, Spain
Offline Offline
Faraday Member
**
Karma: 149
Posts: 5618
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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.


« Last Edit: January 09, 2013, 06:40:02 am by fungus » Logged

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

Rhode Island - USA
Offline Offline
Full Member
***
Karma: 0
Posts: 156
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset


yeah i've seen that vid and this one..


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..
« Last Edit: January 09, 2013, 07:25:04 am by Ruffsta » Logged

Pages: 1 [2]   Go Up
Jump to: