Flip-Dot Display Brought Out Of Retirement By New Drivers

November 21, 2017 by Dan Maloney 16 Comments

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” →

Hackaday Prize Entry: ESPMetric, A Simple And Easy Matrix

August 31, 2017 by John Baichtal 5 Comments

There’s a lot you can do with a bunch of LEDs connected to the Internet. You can display the time, the weather, the bus schedule, or any one of a number of important data points in your life. Custom matrices are a pain in the butt to set up, which is why we like to see one looking rather polished and clean. [Faire-soi-meme] prettied up an 8×32 NeoPixel matrix with some diffusers and a grid bezel. It’s the ESPMetric, and it’s also an entry for this year’s Hackaday Prize.

The NeoPixel matrix is controlled by a NodeMcu using elements from [squix]’s ESP82666 weather station code as well as Adafruit’s NeoMatrix library. There is a photoresistor to control brightness as well as 3 buttons to control its various modes. Tapping the buttons brings you by various settings like the time, WiFi status, stock market, and so on.

If you parlez-vous français–or enjoy the Google Translate experience–[Faire-soi-meme] has detailed the build steps on his blog, though you can also download his code from his GitHub repository. There’s a great video of this build, you can check that out below.

Continue reading “Hackaday Prize Entry: ESPMetric, A Simple And Easy Matrix” →

Graduation Cap Shows Us What It’s Got!

June 30, 2017 by James Hobson 15 Comments

A high school graduation ceremony is well due the pomp and circumstance for making it through one of life’s many milestones. To commemorate the event with their own flair, redditor [PM_(cough)_FOR_KITTENS] hid a 32 x 32 GIF-playing LED matrix in their graduation cap!

The board is controlled by a Teensy hosting a SmartMatrix shield. With the shield’s assistance, the matrix enables scrolling text and GIFs to play across the LEDs, as well as an SD card slot to load up your favourites. Currently, it’s set to a 50-50 chance of playing a gif — one of sixty — or one of the twenty scrolling text lines loaded onto the SD card. [PM_(ahem)_FOR_KITTENS] co-opted his friend’s expertise to write the code — available here — while he designed the circuit and handled the assembly.

Carefully unwrapping his cap, [PM_(yep)_FOR_KITTENS] reinforced it with thinner and stronger cardboard, cutting slots into it, allowing the boards and wires to — barely — fit inside. A hole in the side of the cap is enough for a barely noticeable USB cable to run down his neck to a 2000 mAh battery which can power the cap for over five hours at 5V and 2A. Check out a demo video after the break!

Continue reading “Graduation Cap Shows Us What It’s Got!” →

DIY Shortcut Keyboard

June 19, 2017 by Inderpreet Singh 17 Comments

Working with CAD programs involves focusing on the task at hand and keyboard shortcuts can be very handy. Most software packages allow the user to customize these shortcuts but eventually, certain complex key combination can become a distraction.

[awende] over at Sparkfun has created a Cherry MX Keyboard which incorporates all of the Autodesk Eagle Shortcuts to a single 4×4 matrix. The project exploits the Arduino Pro Mini’s ability to mimic an HID device over USB thereby enabling the DIY keyboard. Pushbuttons connected to the GPIOs are read by the Arduino and corresponding shortcut key presses are sent to the host machine.

Additional functionality is implemented using two rotary encoders and the Teensy encoder library. The first knob functions as a volume control with the push-button working as a mute button. The encoder is used to control the grid spacing and the embedded button is used to switch between imperial and metric units. The entire code, as well as the schematic, is available on GitHub for your hacking pleasure. It’s a polished project just ready for you to adapt.

The project can be extended to be used with other computer software such as Gimp and the keys may be replaced by capacitive touch sensors making it more sturdy. Bluetooth can be added to make things wireless and you can check out the Double Action Keyboard to extend functionality further. Continue reading “DIY Shortcut Keyboard” →

Manhattan Marauder’s Map

April 19, 2017 by Dan Maloney 7 Comments

If you solemnly swear that you are up to no good, and you happen to spend most of your time in Manhattan below the mid-90s, then you will appreciate this Raspberry Pi-based Manhattan Marauder’s Map.

Not that a Harry Potter-themed map was necessarily [GawkyFuse]’s intention when creating this interesting build; it’s just that the old-time print of Manhattan — it shows Welfare Island in the East River, which was renamed Roosevelt Island in 1971 — lends a nice vintage feel to the build. Printed on plain paper, the map overlays a 64×32-LED matrix, which is driven by a matrix HAT riding atop the Pi 3.

[GawkyFuse] uses the OwnTracks app on his and his wife’s iPhone to report their locations back to CloudMQTT. The Pi subscribes to the broker and updates his location in red and her location in blue as they move about the city; a romantic touch is showing a single purple dot when they’re together. There’s no word on what’s displayed when either leaves the map area, but the 2048-pixel display offers a lot of possibilities.

We’ve seen a Weasley clock or two around these parts before, but strangely no Marauder’s Maps like this one. Although this Austrian tram-tracking map comes pretty close to [GawkyFuse]’s nice design.

[via r/raspberry_pi]

NeoJoints Make WS2812 LEDs Even More Fun

March 12, 2017 by Elliot Williams 19 Comments

What’s more fun than individually addressable RGB LEDs? Many, many individually addressable RGB LEDs. What’s more fun than all the miscellaneous soldering involved in connecting many of these cheap and cheerful strips together? Well, basically anything. But in particular, these little widgets that [todbot] designed help make connecting up strips of RGB LEDs a snap.

[todbot]’s connectors aren’t particularly groundbreaking, but they’re one of those things that you need the moment you first lay eyes on them. And they’re a testament to rapid prototyping: the mounting holes and improved routing patterns evolved as [todbot] made some, soldered them up, mounted them, and then made some more. We’d like to see some odd angles, of course, but that shouldn’t be too hard to arrange. Everything is up on GitHub, so you can go check it out.

Of course, necessity is the mother of invention, and she’s got many kids. Which is to say that we’ve seen a variation of this hack before precisely because other folks have stared at this matrix-of-strips problem before and come up with similar solutions. Still, we really like the mounting holes and overall aesthetic of [todbot]’s solution, and if you ever find yourself joining WS2812 strips together, give it a try.

Massive Pixel Display Holiday Decoration

December 20, 2016 by James Hobson 15 Comments

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.

[via /r/DIY]