Dumpster Finds Combined Into 4K Desktop Monitor

March 6, 2020 by Tom Nardi 31 Comments

Dumpster diving is a time honored tradition in the hacking community. You can find all sorts of interesting hardware in the trash, and sometimes it’s even fully functional. But even the broken gadgets are worth taking back to your lair to strip for parts. If you’re as lucky as [Jamz], you might be able to mash a few devices together and turn them into something usable.

In this case, [Jamz] scored a LG 27UK650 monitor with a cracked display and a Dell OptiPlex 7440 “All-in-One” computer that was DOA. Separately these two pieces of gear were little more than a pile of spare parts waiting to be liberated. But if the control board could be salvaged from the monitor, and the working LCD pulled from the Dell…

After taking everything apart, [Jamz] made a frame for this new Frankenstein monitor using pieces of aluminum channel from the hardware store and 3D printed side panels. With the Dell LCD mounted in the skeletal frame, the control board from the LG monitor was bolted to the back and wired in. Finally the center section of the LG monitor’s back panel was cut out and mounted to the new hybrid display with a 3D printed frame.

Admittedly, these were some pretty solid finds as far as trash goes. You won’t always be so lucky. But if you can keep an open mind, the curb is littered with possibilities. How about some impressive home lighting that started life as a cracked flat screen TV?

MIL-SPEC Keyboard Now Salutes USB

February 27, 2020 by Kristina Panos 6 Comments

When [easyjo] picked up this late ’80s Marconi mil-spec keyboard for cheap, he knew it wouldn’t be easy to convert it to USB — just that it would be worth it. Spoiler alert: those LEDs aren’t a mod, they’re native. They get their interesting shape from the key traces, which are in the four corners.

Despite having way-cool buttons such as WPNS HOLD, and the fact that Control is on the home row where it belongs, this keyboard does not look fun to type on at all for any length of time. Of course, the point of this keyboard is not comfort, but a reliable input device that keeps out dust, sweat, liquids, and the enemy.

This is probably why the controller is embedded into the underside of the key switch PCB instead of living on its own board. [easyjo] tried to analyze the signals from the existing 26-pin connector, but it didn’t work out.

So once he was able to decode the matrix, he removed the controller chip and wired the rows and columns directly to an Arduino Leonardo. Fortunately, the LEDs were just a matter of powering their columns from the front side of the board.

The availability of certain kinds of military surplus can make for really interesting modernization projects, like adding POTS to a field telephone.

Via r/duino

Little Printer Dispenses Short Stories

February 25, 2020 by Ted Yapo 11 Comments

We know how it happens. You buy a fancy new label printer, thinking this is the answer to your disorganized space, but soon entropy grabs the printer as well, and it becomes just another item in the pile. When you find such items later, though, they can spark ideas. The idea that struck [Eric Nichols] was to turn his diminutive thermal printer into a dedicated one for short stories.

Inspired by an article about a vending machine that dispenses stories selected by the reader’s time constraints, [Eric] took on the task of getting his Dymo LabelWriter 400 Turbo working in this new capacity. The first task was finding some continuous roll paper that would fit, because the official stock for this thing is all labels. He got lucky on the first try and a roll of 2 7/16″ receipt paper fit the bill perfectly.

The printer itself doesn’t have much brains; it prints bitmaps 672 bits wide, and as long as you care to make them. While the initial experiments succeeded in printing graphics, [Eric] needed a way to convert his stories to bitmapped text to send to the printer. The human-readable font file format known as BDF (glyph Bitmap Distribution Format) was a perfect fit, since a library to render it was readily available. On top of that, the open-source tool otf2bdf will convert a TrueType (TTF) font to BDF, completing his font-rendering chain.

[Eric] has these printers working with both Linux and windows, either one running on a PC where his software resides, and has it all well-documented on his site. With this in place, it’s simply a matter of coming up with the stories to print. We think it would be perfect for Hackaday dailies!

We’ve seen interesting hacks with disused printers before, like this ascii-art generating cartridge.

Stomp Switches Let You Skip Tracks Hands-Free

February 24, 2020 by Tom Nardi 11 Comments

You’ve (probably) got four limbs, so why are you only using half of them when you’re working on the computer? Just because your toes don’t have the dexterity to type (again, probably) doesn’t mean your feet should get to just sit there doing nothing all day. In a recent project, [MacCraiger] shows you just how easy it can be to put some functionality under foot by building a pair of media control stomp switches.

Crimp pin connectors grant +50 professionalism.

If the devices pictured above look a lot like guitar effects, that’s because they share a lot of parts. [MacCraiger] used the same sort of switch and aluminum case that you might see on a pedal board, as he figured they’d be better suited to a lifetime of being stepped on than something he 3D printed.

Up on the desk, and this time in a printed case, is the Arduino Leonardo that they connect to. The wiring for this project is very straightforward, with the switches connected directly to the GPIO pins. From there, the Arduino firmware emulates a USB Human Interface Device and fires off the appropriate media control keystrokes to skip to the next track or pause playback depending on which switch has been engaged.

This hardware isn’t exactly breaking any new ground here, but we did like how [MacCraiger] used standard 3.5 mm audio cable and the associated jacks to connect everything up. It’s obviously on-theme for what’s essentially a music project, but more importantly, gives the whole thing a very professional look. Definitely a tip to mentally file away for the future.

For the more accomplished toe-tapper, our very own [Kristina Panos] recently recently took us through the construction of her macro slinging footstool. Between these two examples of bespoke peripherals, you should have everything you need to create your own custom input devices. We suppose you could even make one that’s hand operated if you’re into that sort of thing.

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Inputs Of Interest: Ears To Communication For Everyone

February 19, 2020 by Kristina Panos 20 Comments

Welcome back to Inputs of Interest! If you haven’t heard, I am all ears when it comes to new ways of talking to computers and machines. And speaking of ears, did you know they can do useful tricks? If you squeeze your eyes shut tightly and/or yawn widely, you might hear a low-level rumbling sound like distant thunder. A decent percentage of people are able to move theirs voluntarily, but not everyone. Maybe you already knew you could rumble, and have used it to entertain yourself, or dampen the unpleasant sounds of life.

No, you can’t reach your tensor tympani with a Q-tip. Image via Research Gate

That rumbling is caused by a muscle in your middle ear stretching out. It’s called the tensor tympani, and its purpose is to shield your ears from loud sounds like chewing, and oddly enough, thunder. When the tensor tympani are activated, they pull the eardrums taut to keep them from vibrating and getting damaged. Unfortunately, they don’t react quickly enough to protect us from sudden sounds like gunshots.

Nick G is able to rumble on command, and wanted to see if he could somehow use it as an input mechanism that he calls Earswitch. He got a cheap USB otoscope camera and figured out that the tensor tympani’s stretching movement shows up well enough to trigger motion detection software. So far, [Nick] has been able to demonstrate control of a few things, like the Windows on-screen keyboard, Grid3 assistive software, and a head tracking utility.

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Sherbet Custom Game Pad Is Smooth And Sweet

February 17, 2020 by Kristina Panos 25 Comments

When [Billiam]’s beloved Logitech G13 game pad went to that great spectate room in the sky, he decided to pay homage by designing a custom, more ergonomic replacement from the desk up. Grab a spoon and dig into the story of [Billiam]’s journey toward Sherbet, because it’s a sweet ride.

Here’s the scoop: like a lot of DIY game pads and keyboards, Sherbet is based on the Teensy. We often see the micro USB coming straight off the Teensy, especially in clear acrylic builds, but [Billiam] added a USB breakout board so there’s no direct stress on the Teensy itself.

One of [Billiam]’s design challenges comes from the game pad placement — he has a tall desk and uses a keyboard tray, so it has to fit the space and leave enough room for his hand. Fortunately, there are low-profile mechanical switches out there, although the keycap options are strongly limited. We love that [Billiam] embedded a tiny ceramic bearing into one of them to use as a homing bump, because that’s a great idea.

If you want to take a crack at this project, [Billiam] has all the goodies laid out. [Billiam] wanted to use QMK firmware, but they didn’t have joystick support yet, so he’s got an Arduino sketch running in the meantime.

We love a good custom game pad around here, especially if they can reprogram themselves.

Emulating A Bluetooth Keyboard With The ESP32

February 13, 2020 by Tom Nardi 16 Comments

Most people associate the ESP family of microcontrollers with WiFi, which makes sense as they’ve become the solution of choice for getting your project online quickly and easily. But while the WiFi capability might be the star of the show, the ESP32 also comes equipped with Bluetooth; we just don’t see people using it nearly as often. If you’re looking to get started using Bluetooth on the ESP32, then this simple wireless macro keypad from [Brian Lough] would be a great way to get started.

From a hardware standpoint, this project is incredibly straightforward. All you need to do is connect a membrane keypad up to the GPIO pins on the ESP32. Adding in a battery is a nice touch, and you probably would want to put it into a enclosure of some sort, but as a proof of concept it doesn’t get much easier than this. In this case [Brian] is using the TinyPICO board, but your personal ESP32 variant of choice will work just as well.

The rest of the project is all software, which [Brian] walks us through in the video after the break. There’s a preexisting library for Bluetooth Human Interface Device (HID) emulation on the ESP32, but it needs to be manually installed in the Arduino IDE. From there, he demonstrates how you can build up a functioning keyboard, including tricks such as sending multiple virtual keys at once.

In the past we’ve seen the ESP32 used to create a Bluetooth game controller, but the ability to emulate a keyboard obviously offers quite a bit more flexibility. With a practical demonstration of how easy as it is to turn this low-cost microcontroller into a wireless input device, hopefully we’ll start seeing more projects that utilize the capability.

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