A Raspi Ambilight With HDMI Input


With the Raspberry Pi now most famously known as a $30 media PC, it only makes sense that the best uses for the GPIO pins on the Pi are used for an Ambilight. [Great Scott Labs] put up a great video on using the Pi as a uniquely configurable Ambilight with Hyperion and just about any video input imaginable.

This isn’t the first Ambilight clone [Great Scott] has put together, but for the first version the Ambilight functioned only under Raspbian and not any random HDMI input. The new version solves this by using an HDMI splitter box, feeding into an HDMI to composite converter, and finally into a USB composite capture dongle attached to the Raspi.

With the software in the instructions, the Raspi effectively mirrors the video coming from the video capture dongle. The Pi is running Hyperion to control a strip of WS2801 RGB LEDs, making the back of any TV glowey and blinkey.

Since [Great Scott] is using a component video signal as an input, the adapters necessary to have any device work with this Ambilight are readily available. We’d honestly like to see this build working with the old Commodore disk access screen border going nuts, so be sure to send that in if you ever get that working.

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Handheld Tetris is Retro and We Love It

handheld tetris

[Eduardo Zola] has been playing around with Arduinos, and ever since he started, he wanted to try making a game. Having fond memories of playing Tetris back on Windows 3.1, he decided to try giving a handheld version of it a shot.

He started with two 8×8 Neopixel Matrices due to their simplicity — not to mention the massive library of code available! To make it truly portable, he’s also included a 3.7v 4400mAh lithium ion battery which will keep him gaming for hours. He found a 5-way navigation switch on eBay which makes up the joystick. A small LED bar display tells you what level you’re on, and he’s even included a smaller speaker for music, and a vibrating motor for successfully completed lines in the game!

He borrowed the Tetris algorithm (and added some improvements) from the source code by [Valentin Ivanov], who completed a similar project last fall. Stick around to see a demonstration video of it in action.

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Driving RGB Pixel LEDs With CAT5 Cable


[Teknynja] was working on a project where he needed to drive a few strips of Adafruit Neopixels – WS2812 LED strips – that were located several feet apart. These LED strips draw a lot of current, and are very timing sensitive; anything more than a few feet of wire between the microcontroller and the LED strip will probably result in missed data, voltage drops, dimming LEDs, and possibly a non-functional strip.

The solution, as in all matters concerning long distance transmission of data, was CAT5 cable. [Teknynja] used RS-422 drivers and receivers to pull this task off, with 75174 line drivers receiving signals from a Teensy 3.0, and 75176 bus transceivers reading everything at the other end of a 20 foot cable.

For the power drop issue, [Teknynja] is feeding 12V into a few of the wire pairs in the cable and using a cheap  LM2596 buck converter to step everything down to 5V at the strip.

With a fairly simple circuit, [Teknynja] was able to drive a few strips of WS2812 LEDs through 20-foot lengths of CAT5 cable with ease; it worked just the same as if the pixels were connected directly to the Teensy on a workbench.