Wireless LED bars!
I've got this set of Revoltec LED backlight bars. They're meant as a form of static ambilight mounted behind a screen. The bars are normally controlled via a small IR remote control with annoying membrane keys. Finding the RGB color I want right now by pressing those keys endlessly for each color channel was no great joy either. Therefore I use a Carambola 2 as... well... GPIO-Wifi adapter. :) This way I can even implement different color models (HSV!).
To put the C2 in control, the ATMega8 was removed from the original PCB and I soldered the C2's GPIOs to the corresponding lanes where that ATMega used to give the orders. As they're both working with 3.3V levels, everything is fine and I can even power the C2 through the original 12V power supply (and a voltage converter). The PCB now receives three PWM signals (RGB) and converts them to 12V for the bars. I'm not sure if USB connectors are a very wise choice for that. Plugging a USB stick in there will probably smell pretty funny.
Thanks to Mathias Gottschlag for providing me with his C2 and lots of hardware knowledge. (I'm really more of a software guy...)
You need to copy src/web/framework7 to host:/www/wled manually once. After that, make && make web installs everything else to the right locations. This is done so that subsequent web target calls don't take so long. The web interface will then be available at http://host/wled.
For wledd to start automatically, you'll need to /etc/init.d/wledd enable to create the necessary symlinks.
Hint: Bookmarking the web interface on the iOS home screen makes it behave quite like a native app.