The first thing needed is a more potent power supply. The 2 Amp supply included with the project pack is perfect for one strand of RGB pixels, but for two to six strands (50 to 150 LEDs) you’ll instead want to use our 5 Volt 10 Amp power supply:
The trick here is to minimize the length that power needs to travel along the LED strands. This ensures better brightness and more uniform color. As explained in the project pack tutorial, 5V can be applied at either end of a strand. We exploit this in the 50 LED setup above by connecting power near the middle…25 LEDs are powered in one direction, and 25 the other.
With more than 50 LEDs you’ll need to provide additional connections for power. This could be done at the start of every strand…but using the same trick as above, it’s also possible to alternate strands: for 100 pixels, connect power to the wires at the end of the first and third strands, and the others will receive power through the mating connectors.
To connect to the strand power wires, you can either solder and insulate these connections, or use Euro-style terminal blocks — these can be clipped apart to provide two + and two – junctions.
The Adalight Processing sketch will require modification. This is the tricky part that’s specific to your setup…it’s not a simple copy-and-paste change, because televisions have different bezel sizes, stands, speakers or other obstructions to take into account. Arts and crafts time!
We need to sketch out a grid that’s close to the shape of the screen, with the right number of squares around the perimeter to match our LED strands. It’s recommended that you try a few sizes and iterations on paper. You don’t have to put LEDs in the corner squares (some users don’t like the look and will skip them), and in the end you might end up with a few more LEDs than grid squares — that’s okay, you can bundle the extra unused LEDs behind the screen.
Number the columns starting from 0 at the left, and the rows starting from 0 at the top. We’ll need these coordinates later for telling the software the position of each LED pixel. One common arrangement with 50-pixel installations has 17 squares across and 10 squares down, because it’s close to the 16:9 aspect ratio of most HDTVs. Grid location (0,0) will then refer to the top left square, and (16,9) to the bottom right.
I like to put the first LED (the one closest to the Arduino) at the bottom center of the screen, because the USB and power cords can be bundled alongside other cables already coming from the display. But you can start at any position, whatever works best with your own telly.
Open the Adalight sketch in Processing and look for the following block of code starting around line 68:
Next, look for this block of code, starting around line 87:
If you try to run the modified program but it throws an error, you’ve probably mis-typed one of these number sets. Make sure there are three numbers in each set, separated with commas both between numbers and between sets.
Load the Adalight.pde sketch in Processing. Then, from the “File” menu, select “Export Application.” Select your OS type, do not check the full-screen option, then click the “Export” button. This will create an application folder containing the standalone program and some support files. You can quit Processing now and just use the standalone version.
We’ve experimented with a stealth windowless version of Adalight…can’t say for certain how reliable this technique will be across all different systems, but you can try out the technique described in this this forum discussion and see what you get.
Because we didn’t write these packages and aren’t familiar with their inner workings, we can’t provide technical support. If you’re having trouble getting an Adalight system up and running, we’ll always ask that you start with the Processing sketch first. Once that’s working, then feel free to explore.
We’ve found Lightpack to be easy to use with a nice GUI and good performance. Don’t download the firmware file, just the software — with Adalight mode selected, this works with our LEDstream sketch already on the Arduino. The Russian site for Lightpack is a little more bleeding-edge, and includes Mac and Linux versions.
Boblight is another popular choice among Linux users. This is perhaps the most complex to set up, even moreso than the Processing code. With the right plug-in it’s said to also work with xbmc, but we’ve never gotten this far with it.