Big Pixel Array

[nickelflipper]

Hi,

Newbie here with first post. Great site by the way, very informative, with lots of interesting and intriguing projects. Read up on lots of lengthy posts, kind of overwhelming.

Anyway, I am thinking of making a large 2ft. by 4ft RGB pixel display, arranged in a 16 x 8 matrix per the attachment. The pixel size will be approximately 2 in. in diameter on 3 in. centers. The led modules will be individually controlled by a PIC with TLC5940 (http://focus.ti.com/docs/prod/folders/print/tlc5940.html) constant current sink drivers with PWM. Power supply to be 12V 250-350W per every two displays, suggestions?

10095

Wanting a bright display in an interior space, I think a 12V source is appropriate with three 5050 RGB leds similar to these (http://www.aliexpress.com/fm-store/701799/209889132-291746166/Waterproof-SMD-LED-Module-3pcs-5050-SMD-LED-RGB-color-.html). My question here is has anyone used these, and can they be manually controlled?

Another option is to find or make up individual (i.e. 3 each) 5mm R, G, and B strawhat (http://cgi.ebay.com/1000pcs-5mm-straw-hat-green-LED-Wide-Angle-/330549526335?pt=LH_DefaultDomain_0&hash=item4cf6497f3f) pixels on a selfmade board. Are these available in the market place?

I know that string and strip lights would be a cheap way to go, but either for brightness reasons, or the display case form factor, doesn't seem to be a viable way to go.

Thanks for any help, links or comments.

[TimW]

Welcome to DIYC!

Pretty sure those will work... They are manually controlled with separate RGB lines.

Note Ray also has stuff like this (http://www.aliexpress.com/fm-store/701799/209889132-441782956/20pcs-string-waterproof-led-pixel-module-3pcs-SMD-RGB-5050-1pcs-LPD6803-32-gray-level-DC12V.html) on his site that is the same form factor and brightness... with the control chip built in (there are several variants). Your solution would then have to communicate in the appropriate protocol to tell them what levels/color to set... but you'd need to do that with your pic solution as well?

DIY folk have been having a lot of fun recently getting these devices incorporated into christmas displays - so there should be plenty of help around if you need it.

[dmoore]

I've done pretty much the same thing with the MegaMatrix - pixel modules inside a coro container to create a huge "JumboTron":

http://www.holidaycoro.com/MegaMatrix.asp

[nickelflipper]

TimW:
Thanks, DIYC is great!

Yes, having the controller on board with the pixels "uncomplicates" things a lot. May go that route depending on budget, and time constraints. The main problem that I see with the off pixel tlc5940 driver concept, is it quickly becomes a wiring and connector project, yuck.

My background has been playing around with microcontrollers (PICs mostly) for the last several years as a hobby. Have worked with some '595 shift registers, and an I2C PCA9635 led driver, but not to the scale that the DIYC people have.

dmoore:
Very nice project, it's huge. I had browsed another video of yours, without really thinking about those columns.

Any deference between the 3x 5050's, and the 9 individual r,g,b led modules, in terms of brightness, or color mixing?

[dmoore]

Any deference between the 3x 5050's, and the 9 individual r,g,b led modules, in terms of brightness, or color mixing?

The color mixing on the 5mm leds isn't as nice as it is with the 5050's but if you are putting them inside a diffused environment, go for it!