Glowing and blinking things are some of our favourite projects around these parts, and the bigger, the better. [Thomas] wrote to us recently to share the design and construction of a large LED wall at the Oregon Museum of Science, and the results are nothing short of impressive.
The concept involved a large LED wall that would be completely hidden when switched off. The team decided to approach this by hiding high-brightness LED panels using APA102 strings behind milky-white plexiglass panels covered with a woodgrain print. The screen has a total of 90,000 pixels, arranged in a 408×220 resolution display.
A lot of bespoke LED displays have some pre-coded patterns, or perhaps some basic reactive features. In this case, FPGA grunt was brought to bear on the problem and the display accepts standard HDMI input. Four Spartan 6 Mojo FPGA boards split up the task of addressing the panels, each receiving the same HDMI signal, but only crunching the pixels relevant to their area of the display. To make sure clean SPI signals get to each panel, special RS485 driver chips are used to send the signal over a differential pair from the FPGA, before breaking the signal back out to standard SPI at the destination.
Building such a large display takes special techniques, and [Thomas] notes that the help of a local construction company was imperative to making the construction of the final video wall look easy. It’s always interesting to see what goes into these large installations. Sometimes, a major build can even clear out world stocks of important components.
One of the most popular uses for the Raspberry Pi in a commercial setting is video walls, digital signage, and media players. Chances are, you’ve probably seen a display or other glowing rectangle displaying an advertisement or tweets, powered by a Raspberry Pi. [Florian] has been working on a project called info-beamer for just this use case, and now he has something spectacular. He can display a video on multiple monitors using multiple Pis, and the configuration is as simple as taking a picture with your phone.
[Florian] created the info-beamer package for the Pi for video playback (including multiple videos at the same time), displaying public transit information, a twitter wall, or a conference information system. A while back, [Florian] was showing off his work on reddit when he got a suggestion for auto-configuration of multiple screens. A few days later, everything worked.
Right now, the process of configuring screens involves displaying fiducials on each display, taking a picture from with your phone and the web interface, and letting the server do a little number crunching. Less than a minute after [Florian] took a picture of all the screens, a movie was playing across three weirdly oriented displays.
Below, you can check out the video of [Florian] configuring three Pis and displays to show a single video, followed by a German language presentation going over the highlights of info-beamer.
Continue reading “Multiple Monitors With Multiple Pis”
Well this is something we haven’t seen before.
A video wall An 8-bit style video wall made from 160 RGB illuminated gaming keyboards.
On display at the PAX East gaming expo, the keys on 160 Logitech keyboards make up the “pixels” of a video wall showing a short film inspired from side-scroller video games. It’s the work of the production company iam8bit. Details on the system are scant, but we can learn a little from close observation of the video.
Continue reading “8-bit Video Wall Made From 160 Gaming Keyboards”
There’s no denying that giant video walls are awesome, but creating one usually means a fairly complex setup with either multiple computers or very expensive video cards. Now, with Pi Wall, you can make a video wall as large as your wallet will allow with only one Raspi per monitor, and a single master pi to control the whole shebang.
As long as you have a few displays with an HDMI input, it’s easy to turn them into a giant monitor. Just plug one Pi per monitor into a network switch, have a Pi (or other Linux box) transmit a video to all the video tiles, and sit back and enjoy the show.
Right now there is an installation guide for creating a Pi Wall, but there are a few limitations; this software only works with the video player provided with the Raspberry Pi, omxplayer. If you’re looking to create an enormous display for a flight simulator or what have you, you might need to do a bit of tinkering under the hood.
Five Rasberry Pi’s are used to drive this four-display video wall. This screenshot shows the system playing back some BBC documentaries. The sync, alignment, and video quality all seem to be spot on which makes it quite easy for your eye to assemble the images into one picture.
Each screen has its own Raspberry Pi which generates the HDMI video shown on the screen. These are fed from one central RPi board which acts as the controller. Video is pushed between the boards using the Real Time Streaming Protocol (RTSP) available through the Linux GStreamer package. Synchronization between the different video boards is taken care of using network time. [Samer] mentions that this system is scalable — each additional screen simply requires one more RPi to drive it.
The team also did some experiments with live video. They added a sixth RPi board with the camera module in order to display a live feed.