LED matrix displays and flat-screen monitors have largely supplanted old-school electromechanical models for public signage. We think that’s a shame, but it’s also a boon for the tinkerer, as old displays can be had for a song these days in the online markets.
Such was the case for [John Whittington] and his flip-dot display salvaged from an old bus. He wanted to put the old sign back to work, but without a decent driver, he did what one does in these situations — he tore it down and reverse engineered the thing. Like most such displays, his Hannover Display 7 x 56-pixel flip-dot sign is electromechanically interesting; each pixel is a card straddling the poles of a small electromagnet. Pulse the magnet and the card flips over, changing the pixel from black to fluorescent green. [John] used an existing driver for the sign and a logic analyzer to determine the protocol used by the internal electronics to drive the pixels, and came up with a much-improved method of sending characters and graphics. With a Raspberry Pi and power supply now resident inside the case, a web-based GUI lets him display messages easily. The video below has lots of details, and the code is freely available.
You may recall [John] from a recent edge-lit Nixie-like display. Looks like he’s got a thing for eye-catching displays, and we’re fine with that.
Continue reading “Flip-Dot Display Brought Out of Retirement by New Drivers”
There are many designs for little two-wheeled robots available to download for constructors with an interest in simple robotics. You might even think there are so many that there could not possibly be room for another, but that has not deterred [Rob Miles]. He’s created HullPixelBot, a platform for a mobile pixel as well as for simple robotic experimentation.
So what makes HullPixelBot more than just Yet Another Arduino Powered Robot? For a start, it’s extremely well designed, and has a budget of less than £10 ($12.50). But the real reason to take notice lies in the comprehensive software, which packs in a language interpreter and MQTT endpoint for talking to an Azure IoT hub. This is much more than a simple Arduino bot on which you must craft your own sketches, instead, it is a platform for which the Arduino bot is merely the carrier.
The project has had quite a while to mature since its initial release, and now has the option of a single pixel or a ring of pixels. The eventual aim is to use swarms of networked HullPixelBots to create large autonomous moving pixel displays, containing more than a hundred individual pixels.
There is an early video of some PixelBots in action which we’ve placed below the break, but it serves more as eye candy than anything else. If you have a spare ten quid, download and print yourself a chassis, install Arduino and motors, and have a go yourself!
Continue reading “Hull Pixel Bot, A Mobile Pixel”
The Raspberry Pi Foundation has put a lot of work into their software stack. You need only look at a few of the Allwinnner-based Pi clones for the best evidence of this, but the Pi Foundation’s dedication to a clean and smooth software setup can also be found in Noobs, their support for the Pi Hardware, and to a more limited extent, their open source GPU driver offerings.
Now the Pi Foundation is doing something a bit weird. They’re offering their default Raspberry Pi installation for the Mac and PC. Instead of Flashing an SD card, you can burn a DVD and try out the latest the Pi ecosystem has to offer.
A few months ago, PIXEL became default distribution for the Raspberry Pi. This very lightweight distribution is effectively the Knoppix of 2016 – it doesn’t take up a lot of resources, it provides enough software to do basic productivity tasks, and it’s easy to use.
Now PIXEL is available as a live CD for anything that has i386 written somewhere under the hood. The PC/Mac distribution is the same as the Pi version; Minecraft and Wolfram Mathematica aren’t included due to licensing constraints. Other than that, this is the full Pi experience running on x86 hardware.
One feature that hasn’t been overlooked by a singular decade-old laptop in the Pi Foundation is Pixel’s ability to run on really old hardware. This is, after all, a lightweight distribution for the Raspberry Pi, so you shouldn’t be surprised to see this run on a Pentium II machine. This is great for a school in need of upgrading a lab, but the most interesting thing is that we now have a new standard in Linux live CDs and Flash drives.
Decorating for the holidays is serious business! Finding themselves surrounded by neighbours who go big, redditor [wolfdoom] decided that this was the year to make a strong showing, and decided to build an oversized pixel LED display.
Demonstrating resourcefulness in their craft, [wolfdoom] found an old fluorescent light grid pattern to prevent bleed from one pixel to the next. Reusing this grid saves many hours of precision-cutting MDF — to be substituted with many hours of cutting the plastic with decidedly more room for error. Attaching the resulting grid to a sheet of plywood, and 576(!) drilled holes later, the LEDs were installed and laboriously wired together.
A Plastic light diffusing sheet to sell the pizel effect and a little help from their local maker space with the power circuit was enough to keep this project scrolling to completion — after the requisite period of basement-dwelling fabrication.
Despite some minor demotion attributed to a clumsy daughter, the massive 4×4 display remained a suitably festive decoration. For now the control system remains in [wolfdoom]’s basement, but with plans to incorporate it into the display’s frame down the road.
One of the more interesting LED matrix builds we saw this year is the one that uses 1575 beer bottles. For a more interactive holiday decorations, Halloween usually takes the cake — like this animated door knocker.
Two days at a company sponsored hackathon? Sounds like fun to us! And productive too – the end result for [GuuzG] and two of his workmates from their company’s annual “w00tcamp” was this festive and versatile 16×16 pixel mega display.
From the sound of it, [GuuzG] and his mates at q42.com are not exactly hardware types, but they came up with a nice build nonetheless. Their design was based on 16 WS2812 LED strips for a 256 pixel display. An MDF frame was whipped up with cross-lap joints to form a square cell for each pixel. Painted white and topped with a frosted Plexiglass sheet, each RGB pixel has a soft, diffuse glow yet sharply defined borders. Powered by a pair of 5A DIN rail DC supplies and controlled by a Raspberry Pi, the finished display is very versatile – users can draw random pixel art, play the Game of Life, or just upload an image. [GuuzG] and company are planning to add Tetris, naturally, and maybe a webcam for fun.
We’ve seen lots of uses for the ubiquitous WS2812 LEDs, from clocks to Ambilight clones to ground-effect lighting for an electric skateboard. But if you’re in the mood for a display that doesn’t use LEDs, there’s always this multithreading display.
[Warrior_Rocker’s] family bought a fancy new sign for their beach house. The sign has the word “BEACH” spelled vertically. It originally came with blue LEDs to light up each letter. The problem was that the LEDs had a narrow beam that would blind people on the other side of the room. Also, there was no way to change the color of the LEDs, which would increase the fun factor. That’s why [Warrior] decided to upgrade the sign with multi-colored LEDs.
After removing the cardboard backing of the sign, [Warrior] removed the original LEDs by gently tapping on a stick with a hammer. He decided to use WS2811 LED pixels to replace the original LEDs. These pixel modules support multiple colors and are individually addressable. This would allow for a wide variety of colors and animations. The pixels came covered in a weatherproof resin material. [Warrior] baked the resin with a heat gun until it became brittle. He was then able to remove it entirely using some pliers and a utility knife. Finally, the pixels were held in place with some hot glue.
Rather then build a remote control from scratch, [Warrior] found a compatible RF remote under ten dollars. The LED controller was removed from its housing and soldered to the string of LEDs. It was then hot glued to a piece of cardboard and placed into the sign’s original battery compartment. Check out the video below for a demonstration. Continue reading “LED Sign Brightens Up The Beach After Dark”
[Jordan] managed to cobble together his own version of a low resolution digital camera using just a few components. The image generated is pretty low resolution and is only in grey scale, but it’s pretty impressive what can be done with some basic hardware.
The heart of the camera is the image sensor. Most consumer digital cameras have tons of tiny receptors all jammed into the sensor. This allows for a larger resolution image, capturing more detail in a smaller space. Unfortunately this also usually means a higher price tag. [Jordan’s] sensor includes just a single pixel. The sensor is really just an infrared photodiode inside of a tube. The diode is connected to an analog input pin on an Arduino. The sensor can be pointed at an object, and the Arduino can sense the brightness of that one point.
In order to compile an actual image, [Jordan] needs to obtain readings of multiple points. Most cameras do this using the large array of pixels. Since [Jordan’s] camera only has a single pixel, he has to move it around and take each reading one at a time. To accomplish this, the Arduino is hooked up to two servo motors. This allows the sensor to be aimed horizontally and vertically. The Arduino slowly scans the sensor in a grid, taking readings along the way. A Processing application then takes each reading and compiles the final image.
Since this camera compiles an image so slowly, it sometimes has a problem with varying brightness. [Jordan] noticed this issue when clouds would pass over while he was taking an image. To fix this problem, he added an ambient light sensor. The Arduino can detect the amount of overall ambient light and then adjust each reading to compensate. He says it’s not perfect but the results are still an improvement. Maybe next time he can try it in color.