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.
Before we get ahead of ourselves: no, not that DEF CON. Instructables user [ArthurGuy] is a fan of the 1983 movie War Games, and following a recent viewing –hacker senses a-tingling — he set to work building his own real-time display.
Making use of some spare wood, [ArthurGuy] glued and nailed together a 10x10x50cm box for the sign. Having been painted white already at some point, the paint brilliantly acted as a reflector for the lights inside each section. The five DEF CON level panels were cut from 3mm pieces of coloured acrylic with the numbers slapped on after a bit of work from a vinyl cutter.
Deviating from a proper, screen-accurate replica, [ArthurGuy] cheated a little and used WS2812 NeoPixel LED strips — 12 per level — and used a Particle Photon to control them. A quick bit of code polls the MI5 terrorism RSS feed and displays its current level — sadly, it’s currently at DEFCON 2.
The project seeks to exploit the traditional symbols of “male” and “female” – the human figures wearing pants or a dress – by creating a sign that switches between the two every 15 seconds. This is likely to initially confuse – one might imagine the bathroom is actually changing its gender designation rapidly, forcing users to complete their business in an incredibly short timeframe. However, the message behind the project is to highlight the absurdity of defining gender by pants, colours, or indeed in a binary nature at all. [Robb] also helpfully points out that all humans have to pass waste, regardless of gender.
The sign is built with 3D-printed components, using a crank mechanism to actuate the moving parts. The mechanism is designed to give equal time to the pants and dress configurations. [Robb] shares the important details necessary to replicate the build, such as how to assemble the metal crank pin insert with a paperclip and a lighter. It’s particularly tidy the way the mechanism is integrated into the parts themselves. In true hacker style, the motor is a standard microwave oven turntable motor, which can be harvested easily from a junk appliance and can be plugged straight into mains power to operate, if you know what you’re doing. If you don’t, check out our primer on the topic.
Overall, the project is a great use of hacker techniques, like 3D printing and harvesting parts, to make a statement and start a conversation, while being fun, to boot. We’ve also seen some of [Robb]’s work before, like this giant hamster wheel for people. Video after the break.
Old hardware you may have on hand cannot only inspire projects in their own right, but can facilitate the realization of any ideas you have been planning. Using a Nokia N900, [MakerMan] concocted a light-up sign with a live subscriber and view count of his videos.
[MakerMan] milled out the logo used on the sign with his DIY CNC machine — built from rotary bearings and recycled stepper motors off industrial Xerox printers. The meticulous application of a jigsaw, rotary tool, and grinder resulted in a sturdy frame for the sign while a few strips of RGB LEDs imbue it with an inspiring glow. All that was left was to mount the phone in place and tape it for good measure.
[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”→
Are you tired of being ignored? Do you want a fashion accessory that says, “Pay attention to me!” If so, you should check out [Al’s] recent instructable. He’s built himself a necklace that includes a display made up of 512 individual LEDs.
This project was built from mostly off-the-shelf components, making it an easy beginner project. The LED display is actually a product that you can purchase for just $25. It includes 512 LEDs aligned in a 16 x 32 grid. The module is easily controlled with a Pixel maker’s kit. This board comes with built-in functionality to control one of these LED modules and can accept input from a variety of sources including Android or PC. The unit is powered from a 2000 mAH LiPo battery.
[Al] had to re-flash the firmware of the Pixel to set it to a low power mode. This mode allows him to get about seven hours of battery life with the 2000 mAH battery. Once the hardware was tested and confirmed to work correctly, [Al] had to pretty things up a bit. Some metallic gold spray paint and rhinestones transformed the project’s cyberpunk look into something you might see in a hip hop video, or at least maybe a Weird Al hip hop video.
The Pixel comes with several Android apps to control the display via Bluetooth. [Al] can choose one of several modes. The first mode allows for pushing animated gif’s to the display. Another will allow the user to specify text to scroll on the display. The user can even specify the text using voice recognition. The final mode allows the user to specify a twitter search string. The phone will push any new tweets matching the terms to the display as scrolling text.
[A Raymond] had some free time at work, and decided to spend it on creating a wireless warning sign. According to his blog profile, he is a PhD student in Applied Physics. His lab utilizes a high-powered laser system. His job is to use said system, but only after it’s brought online by faculty scientists. The status of the laser system is changed by a manual switchbox that controls the warning signs wired around the lab entrances. Unfortunately, if you were in the upstairs office, you only knew this after running downstairs to check. [A Raymond’s] admitted laziness finally got the better of him – he wanted a sign that displayed the laser’s status from the comfort of the office. He had an old sign he could use, but he wanted a way for it to communicate with the switchbox downstairs. After some thought, he decided Bluetooth was the way to go, using a pair of BlueSMiRF Bluetooth modules from Sparkfun and Arduino Uno R3’s.
He constructed a metal box that intercepted the cable from the main switchbox, mounting one BlueSMiRF and Uno into it. Upon learning that the switchbox sends 12V AC signals over three individual status wires, he half-wave rectified the wires and divided their voltages so that the Uno wouldn’t fry. Instead, it determined which status wire that had active voltage. and sent a “g(reen)”, “y(ellow)”, or “r(ed)” signal continuously via Bluetooth. On the receiving end, [A Raymond] gutted the sign and mounted the other BlueSMiRF and Uno into it along with some green, yellow, and red LEDs. The LEDs light up in response to the corresponding Bluetooth signal.
The result is a warning sign that is always up-to-date with the switchbox’s status. We’ve covered projects using Bluetooth before, from plush birds to cameras– [A Raymond’s] wireless sign is in good company. He notes that it’s “missing” a high pitched whining noise when the “Danger” lights are on. If he decides to add an accompanying (annoying) sound, he couldn’t go wrong with something like this. Regardless, we’re sure [A Raymond] is happy that he no longer has to go back and forth between floors before he can use the laser.