Long-Distance Text Communication With LoRa

Affordable and reliable cell phones have revolutionized the way we communicate over the last two decades or so, and this change was only accelerated by the adoption of the smartphone. This is all well and good if you’re living in a place with cellular infrastructure, but if you’re in more remote areas you’ll have to be a little more inventive. This text-based communications device, for example, lets you send text messages without all of that cumbersome infrastructure.

While [Arthur] didn’t create this project specifically for off-grid use, it’s an interesting project nonetheless. The devices use a physical QWERTY keyboard and a small screen, reminiscent of BlackBerry devices from the late 2000s (partially because they are actually using BlackBerry keyboards). One of the other goals for this project was low power consumption, and between polling the keyboard, the memory LCDs, and receiving and transmitting messages using LoRa, [Arthur] was able to get the current draw down to 12 mA.

Between the relatively common nRF52840 and SX1262 chips, plus the fact that [Arthur] made the schematics available, this makes for an excellent off-grid device for anyone who likes to drive off into the wilderness or lives far enough outside of town that cell phone reception is a concern.

Looking for something a little easier to put together before your upcoming camping trip? This similarly styled LoRa communicator from [MSG] uses off-the-shelf modules to greatly reduce the part count. Another option for off-grid communications is to use existing smartphones paired with a LoRa network like we saw in this project.

One Solution, Many Problems

You might think you’re lucky when one of your problems has multiple solutions, and you get to pick and choose, but you’re even luckier when one solution has many problems! This week I stumbled on an old solution in a new place. The project was a fantastic old MIDI guitar build, the Tryndelka by [Aleksandr Goltsov]. And the old solution? Switch matrix diodes.

You see, [Aleksandr] is making an electric guitar where the strings are pulled up to a certain voltage and then make contact with metal frets. Each fret is cut into six pieces, so that the strings can be read out individually, and the microcontroller scans each string in succession to test if it’s pressed down or not. Done, right? Wrong! The problem comes when two or more strings are pressed at once — the electrical path from the string you want will travel through the closed switch on a string that you’re not scanning. The solution is a ton of diodes.

I learned this problem the hard way in wiring up a MAME cabinet, at about 3 A.M. the night before we were going to bring it to Shmoocon. We finally got the whole USB/button code working, so we played some celebratory rounds of Street Fighter. We eventually noticed that hitting one button, or even moving the joystick in a particular direction, would block some of the other buttons from working, or change their function entirely. Quick Internet search later, and we were hand soldering 64 diodes until dawn. Good times!

But the fact that switch matrices need diodes, and exactly why, is forevermore burned in my brain. It’s fun to see it pop up in all sorts of contexts, from DIY keyboards to MIDI guitars, to Charliplexing. (It’s the “D” in LED!) It’s one of the classics — a solution to many problems.

Sunrise Keyboard Looks The Part

If you’ve been to a bar sometime since the 1930s, you’ve probably spied someone drinking a Tequila Sunrise. It’s a drink that mimics the beautiful colors of the dawn. In much the same way, so does this Sunriser keyboard build from [crashl1445].

Built for a high-school engineering project, the build looks resplendent with its yellow case, paired with yellow, orange and pink keycaps to produce the wonderful sunrise aesthetic. The build relies on an Elite-C v4 microcontroller, an off-the-shelf device specifically designed for building custom keyboards. As you might guess from the name, it features a USB-C port, serving as a modernized alternative to the Arduino Pro Micro for custom keyboard builders. KTT Rose switches are used as per [crashl1445’s] own preference, and there’s even a rotary encoder which acts as a volume knob, installed right by the arrow keys. The case is printed in several parts on a Prusa Mk3+, as the keyboard wouldn’t fit entirely on the build plate as a single piece.

The best thing about building your own keyboard is that you can design it entirely to suit your own preferences and aesthetic; we think [crashl1445] did a great job in this regard. If you’re cooking up your own sweet keyboard build, don’t hesitate to let us know!

Thinnest Keyboard Uses Cherry DIY Doubleshot Method

As with any other community, it takes all kinds to make the keyboard world go ’round. Some like them thicc — more backing for the clacking and all — but some like them sleek and prefer the slimmest possible keyboard. For now and the foreseeable future, the go-to method for making whisper-thin keebs is to use Kailh Choc switches, because that’s about all that’s out there.

But chocs aren’t for everyone, and there are plenty of die-hard Cherry fans out there that want it both ways. Being one among them, [Khmel] set about designing the lowest-profile possible keyboard (and caps) that uses standard Cherry-sized keyswitches. Shut up and take your money? Well, okay, but the case and keycap files are all available on Thingiverse, so.

The whole video is great, and at less than 2½ minutes long, it’s definitely worth your time. There are a few little gems of wisdom sprinkled throughout, like printing keycaps standing up on their backsides (like where they would have a little flash dot if they were factory-molded). This gives them a nice texture thanks to the layer lines. But the real reason we’re here today is this DIY method for making doubleshot keycaps with little fuss that [Khmel] just tosses out there toward the end.

Trust us, there’s a piece of glass there.

Traditionally, doubleshot keycaps are made with two layers of plastic — one for the legend, and one for the rest. This produces a quite durable keycap and (used to be the norm), but the expensive process gave way to laser-etched and pad-printed keycap legends in the ’90s. [Khmel] was able to fake the look by printing legends at 0.25 layer height and then fusing each one to its respective keycap by laying a thin piece of glass (think microscope slide) on top and applying a soldering iron for a few seconds. Classy!

Tweezing tiny legends not really your kind of tedium? Here’s a method for DIY waterslide decals instead.

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Mods Make A Stock Keyboard Your Own

Trust me, you don’t have to build your own keyboard from the deskpad up to be happy or feel like one of the cool kids. Sure, it doesn’t hurt, but not everyone is able to or even wants to start from next to nothing. Take [Roger] for example. [Roger] started with a stock mechanical keeb — the Ultimate Hacking Keyboard (UHK) — which can be outfitted with magnetic add-on modules such as a thumb key cluster, trackball, trackpoint, and touch pad, and made it his own.

While the stock board that you choose may not be so option-laden, there are plenty of other things one can do to customize things, and [Roger] did basically all of them. The Kailh browns that the UHK came with were too loud, so [Roger] swapped them out for Zilent V2 Silent tactiles and dampened the case with plenty of neoprene foam.

[Roger] frequently switches between two keyboard layouts, which got confusing at times. But instead of boring blank keycaps, he scrounged around until he found a cool set. (We do like the way they look with the wood wrist rests.) Speaking of those wrist rests, the right one is carved out and hiding a 10,000 mAh power bank, because [Roger] also made the UHK wireless using one of those often-out-of-stock BT-500 Bluetooth adapters. This allows him to switch between two PCs with a keyboard shortcut.

Think you want to go split, but not sure about key wells and column stagger and all that jazz? Something like the UHK is a good place to start, because it takes the familiar brick wall layout and breaks it into two pieces. No idea what you want? Check out the split keyboard finder.

Pico Chording Keyboard Is Simultaneously Vintage And New

On paper, chording — that’s pressing multiple keys to create either a single character or a whole word — looks like one of the best possible input methods. Maybe not the best for speed, at least for a while, but definitely good for conserving the total number of keys. Of course, fewer keys also makes for an easier time when it comes to building keyboards (as long as you don’t have to code the chording software). In fact, we would venture to guess that the hardest part of building your own version of [CrazyRobMiles]’s Pico Chord Keyboard would be teaching your fingers how to work together to chord instead of typing one at a time.

[CrazyRobMiles] took inspiration from the Cykey chording design used for the Microwriter and later, the Microwriter Agenda that also featured a qwerty blister keyboard. Both featured small screens above the six keys — one for each finger, and two for the thumb. While the original Microwriter ran on an 8-bit microprocessor, Pico Chord Keyboard uses — you guessed it — the Raspberry Pi Pico.

We love that [CrazyRobMiles] went with four 14-segment displays, which gives it a nice old school feel, but used transparent keycaps over Kailh switches. This is actually important, because not only do the LEDs show what mode you’re in (alpha vs. numeric vs. symbols), they also teach you how to chord each letter in the special training game mode. Be sure to check it out in the video after the break.

Isn’t it cool that we live in a world of relatively big keyboards with few keys and tiny keyboards with all the keys?

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IBM PCjr Types Again, Thanks To KeybJr

Most of us think of keyboards — even vintage ones — as being fairly standardized and interchangeable, but that isn’t the case for the IBM PCjr. Its keyboard was quite unlike most others of its time, which means that a PCjr without an original keyboard is pretty much a dust collector. That’s what led [Jozef Bogin] to create the KeybJr, a piece of hardware that allows one to use any AT, XT, or PS/2 keyboard with the IBM PCjr.

The PCjr’s oddball keyboard can be a bit of a hassle for vintage computing enthusiasts.

What was strange about the PCjr’s keyboard? From the outside it looked pretty normal, but it definitely had its own thing going on. For one, the PCjr keyboard operated over a completely different protocol than the other keyboards of the time. In addition, its connection to the host was either by IR, or via its own wired cable adapter.

The KeybJr solves this by using an Arduino-based board to turn inputs from other keyboards of the time into something the PCjr expects. These signals are sent out and received either over infrared, or by the PCjr’s “K” port for a wired keyboard link.

Why bother with the IR functionality? Well, the connector and pins on the PCjr are not very rugged, and sometimes they are damaged. In those cases, it is nice to have the option of using a normal (for the time) keyboard over the IR link. Vintage hardware is not always in perfect shape, after all. That’s why things like ATX power supply adapters for the PCjr exist.

Want to give it a shot? There is a GitHub repository for the KeybJr, and you can see it in action in a brief video, embedded below.

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