Ambilight Clone: Smart Screen Backlight

Surround Sound for Your Eyes

I saw a video of the ambilight, and thought it was awesome. I pieced together a few tutorials and write-ups, and edited and adapted a bit ,and took some photos along the way.

Credit Where it is Due

The vast majority of the code work was done by others like: this write-up and this one. My only real contribution was making it bigger.

Prototype

I wanted to see if I could get it to work, so I used what I had around, a string of RGB LEDs, some cardboard, and an Arduino.

Testing Version 1

Version 2

Things I learned from V.1:

• The LED strands are really heavy, I used gaffers tape, and they still kept falling apart. I opted for LED strips for V.2.

• The Arduino is great, the Uno was a but unwieldy though. I wanted to try and get the controller smaller, so I went with a pro-mini clone that had USB integrated. (Note, the clone maker cut corners and instead of the nice FTDI usb it used).

Building Version 2

Cut weight, and even at the lowest 30/m density, it still took 110 LEDs to wrap a 55" TV. Pro: very high resolution backlighting (see that green pixel arm). Con: needed a 6-8a power supply to run it.

Testing Version 2

Initial test was really flicker. The 2A power supply was not cutting it, even at drastically reduced brightness (those 2812Bs are awesome bright, which is good if you want to use them in a lit room).

Work In Progress

Still to do:

• Add schematic for the LED controller.

• Add documentation on feeding the controller via Processing and software, including complications of full screen apps/games.

• Waiting on 5v 8A power supply to come, hoping that clears up the flickering.

Update: New power supply sorted everything out, 8A may be overkill, but it solved the problem.

Note! I have had similar flickering issues in the past when the Arduino and LED strip had separate power and ground feeds (the Arduino cannot be powered by USB and the VIN pin at the same time). In projects where the Arduino is connected by USB (as here, where it is the data connection) and you are using external power (as here, to feed hungry LEDs), make sure the Arduino and LED share a ground or the LEDs will misbehave. It is needed to ground the data line coming from the Arduino.

Mount new build, possibly gatorboard/foamcore? I plan on building in a VESA mount to attach to the TV. Too much work, I ended up using matte black tape to attach it to the back of the TV.