This post is meant to answer some of the questions I’ve received in the ‘comments’ section, as well as through private email exchanges.  Specifically, “Great!  I now have $X hundred pixels.  How do I control them all?”

Having a background in theatre / live production / staging, I lean towards tools written by and for those people.

There are many choices for controlling large arrays of RGB nodes.  A nicely written tutorial on the subject is here.

A google search for ‘pixel mapping software’ will return many options. Price ranges from free to many thousands of dollars, depending on the number of outputs required. Software options include Colour-Tramp by Artistic License,  Chamsys MagiQ PC (free, multiplatform!), RadLite/PixelRange, Green Hippo’s Hippotozer software, and many more.  Also interesting is Landy Bible’s .Matrix program – sort of a poor man’s Catalyst server – which speaks Art-Net and is free from his site.

There’s also possibilities of building custom patches using MAX/MSP.  Finally, the fine folks over at kineme.org have done some neat work using Quartz Composer under Mac OS X, plus plugins for USB-DMX dongles and Art-Net.

Note that our (coming soon!) Art-Net interface will work with all of these commercial programs…

All the bits and pieces we need to develop the Art-Net receiver arrived a couple days ago.  

Yesterday I cobbled them together and wrote some simple webserver code.

Didn’t figure out how to make it viewable from the outside world, but on the shop’s local network the server was functioning perfectly.

‘Hello World,” served from an $8 microprocessor.

Now we know that the ethernet link is good, the next step is to get the Art-Net receiver code up and running.

A couple days ago I was contacted by a gentleman who purchased a decent batch of ‘classic’ pixels a year or two ago.

He’s planning to expand his display and asked if we’d consider running a large batch of *assembled* 5-channel (RGB+W+A) pixels.

The quantity he’s interested in is more than sufficient to justify the setup & tooling fees involved, so we’ll definitely be running enough to cover his order.

The design will be based on this one:

http://response-box.com/rgb/2009/06/diy-pixels-rev2/

…but entirely SMT, save the LEDs and RJ45 connectors.

I’ll omit the three servo connectors but include 6 each wide-angle LEDs for RGB, Amber and White. I’ll also add the standard 5-pin programming header for PIC flashing and a two position header so they can be field addressed using the ‘DIY’ code that’s been floating around for a couple months now (thanks, SRM!).

I’ll also update our standard firmware so that the pixels can be re-addressed using the ‘alternate start code’ datastream that’s worked so well in our shop.

In short, lots of ways to get these up and running.

Price? No idea just yet. Haven’t heard back from the factory. Depending on freight, customs fees, and order quantity I’d expect them to be available somewhere in the $9-$13 range.

Order will likely be placed in early August.

Anyone else want some?

EDIT 6/5/09:  These boards are all gone and have been replaced.  Click Here for the New Version.

Just received 150 of the five channel ‘DIY’ through-hole pixel boards.  The design is basically the same as before, but I’ve added a programming jumper.  

Grab yours from the 

Online Store 

The simple shopping cart will add $5 for USPS Priority Mail (2-3 business day) delivery. International shipping is no problem, I’ll just need to send you a custom invoice.

In the spring, we’re finalizing a design which has the LEDs / drive electronics safely encapsulated in an injection-molded enclosure which will look surprisingly similar to a C9 Christmas light.

However, tooling and setup fees for the machining will be very expensive.  Plus, it takes a long time.

Here’s how I impatiently but quickly weatherproofed the pixels installed on the house.  Click any picture to enlarge.

(Note that though this seems to work well, it took a long time and was fairly boring.  Won’t be doing it again.  Also, I wanted to use regular heat-shrink tubing to seal the parts.  Unfortunately, the header pins and LED are so bendy that nothing sufficiently wide would make a good seal.)

To start, take an assembled, tested and programmed pixel.

Then, buy a roll of Heat Shrink Film from your local professional print shop.  This is the same plastic that’s wrapped around CDs and DVDs from the store.  It came in a 500 foot roll 12″ wide.  If anyone needs about 485 feet of shrink film, let me know.

Buy a Foodsaver clone from Target for about $40.  Useful because it has a strip of heating element which we use to make custom shapes with the shrink film.

Make a bag, sealed on three sides, out of shrink film.  Mine was 12″ long by 3″ wide and open on the 3″ end.

Seal the fourth side.  The plastic ‘pillow’ is now air-tight.  Test the seal by mashing it with your finger.  At this stage it’s important that the circuit be isolated from the rest of the world.

Ever so gently, press the 10 pins of the ribbon cable through the film.  If you do it right, you’ll have 10 small punctures in the plastic.  Do it wrong and the film tears and you start over.

Use a heat gun to shrink the film.  It’s soft and supple when warm – almost like cellophane wrap.  When it sets, it’s crinkly and stiff.  Funny looking up close, totally unnoticeable from a more than a few feet away.

Attach the pixel to the ribbon cable harness previously constructed.  My lights are on 8″ centers.

For even more protection, use a 1″ piece of 3/4″ diameter heatshrink tubing to lock the female and male headers together.  Somewhat like a turtleneck shirt.

Et voila.  I wouldn’t immerse them in water, but it works well to keep off blowing snow and rain.

[click to enlarge]

Half a pixel. Based on the original RGB design but with half the LEDs. 1.25″ square.

Bill of Materials:  

• B1  5mm blue led               
• B2  5mm blue led                        
• B3  5mm blue led                          
• C1  .1 uF 10v ceramic, 0805 package        
• C4  1 uF 10v ceramic, 0805 package       
• C5  10 uF 25v ceramic, 0805 package   
• E1  5mm red led                            
• E2  5mm red led                          
• E3  5mm red led                             
• G1  5mm green led                           
• G2  5mm red led                             
• G3  5mm red led                            
• JP1  .1″ x 5 pinheader, optional    
• JP2  .1″ x 5 pinheader, optional       
• PGM  .1″ x 5 programming header, optional       
• R1  1K 0805   
• R2  1K 0805    
• R3  1K 0805   
• R4 1K 0805      
• R5 300 0805       
• R6 117 0805     
• R7 100 0805     
• T1  2N3904  SOT-23 
• T2  2N3904  SOT-23   
• T3  2N3904  SOT-23  
• U$1 78L05 SOT-89       
• U1  PIC 16F688 SOIC-14                        
• U2  MAX485/SN75176 SOIC-8          

My wife and I were cleaning the garage this morning when a shiny yellow DHL truck pulled in the driveway. I was delighted to receive about 5 Kg of new circuit boards. Among them were…

A new version of the Point Source RGB Pixel design. It’s based on a 10mm RGB LED, a PIC 16F688 microcontroller and an RS-485 receiver. With the exception of the LED itself, all parts on the this board are now surface mount.

No changes here, but I’ve added silkscreen and soldermask. This is a great way to combine power and data into a single Cat5 cable for powering strings of large DMX pixels. The board has a footprint for a Neutrik NC5MAH 5-pin male connector, an RJ45 ‘pixel drive’ jack, an RJ45 ‘DMX IN’ jack (pinout matches the USITT standard) and large solder points for power and ground.

New revision of the ‘Mini Pixel’ design. All components are surface mount except for the LEDs. Contains a 16F688 processor, an RS-485 receiver and a programming header for your hacking pleasure.

Buy these boards and more in the online store.