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.

Raspberry Pi And ESP32-S2 Team Up For MutantC_V4

Back in 2019 we first came across the mutantC, an open source 3D printable Raspberry Pi handheld created by [rahmanshaber] that took more than a little inspiration from Sony’s VAIO ultra-mobile PCs (UMPCs) from the early 2000s. It was an impressive first effort, but it clearly had a long way to go before it could really be a practical mobile device.

Well after two years of development and three iterative versions of this Linux powered QWERTY slider, [rahmanshaber] is ready to show off the new and improved mutantC_v4. Outwardly it looks quite similar to the original version, with the notable addition of a tiny thumbstick and a pair of programmable buttons on the right side that can be used for input in addition to the touch screen. But inside it’s a whole other story, with so many changes and improvements that we hardly even know where to start.

Inside the mutantC_v4, showing off the ESP32-S2

Probably the most notable improvement is the addition of an ESP32-S2, specifically a bare ESP-12K module, to the main PCB. Previous versions of the hardware used an Arduino Pro Micro to interface with all the hardware, but the added horsepower of the ESP32 should come in handy with the array of sensors, controls, and NeoPixels that [rahmanshaber] has tasked the chip with. There’s even a buzzer and a coin-style vibration motor in there to provide some feedback to the user. While the board has changed significantly, it still retains compatibility with the Pi Zero, 2, 3, and 4.

Another notable addition is the expansion connector on the bottom of the handheld that has pins for I2C, UART, and 3.3 V. In the video below, [rahmanshaber] mentions that this feature was previously implemented with a standard 2×6 female header block, but is now using a far slimmer female USB-C port. We do wonder if it’s not a bit confusing to have this faux-USB port right next to the real one that’s actually used to charge the system, but with such cramped quarters occasionally you’ve got to make some tough decisions like that.

It’s quite inspiring to see how [rahmanshaber] has honed his skills since releasing the first version of the mutantC. The 3D printed parts and PCBs have matured considerably over the last two years, showing how quickly a dedicated hobbyist can advance their abilities. The most recent version has been entered in the 2021 Hackaday Prize. But the show isn’t over yet, as we hear v5 of this impressive handheld may tackle the Raspberry Pi 4 Compute Module.

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World’s First RP2040 QWERTY Computer

Independent hardware developer [bobricius] is at it again, making what he claims is the world’s first Pico RP2040 QWERTY + IPS development kit — the PICOmputer. This is a palm-sized computer of sorts. It integrates a keyboard made from tactile push button switches, a TFT IPS display, and a RP2040 Pico computer module. At 100 x 65 mm size, it is slightly bigger than your typical ISO-7810-ID-1-sized credit card, and slightly smaller than an A7 piece of paper.

One of [Bobricius]’s goals for this project was to minimize the number of external components, thus maximizing the use of the RP2040’s internal features. And if you peruse the schematic posted on his GitHub repository, you can agree he’s met this goal for sure. There’s a filter capacitor for the optional LoRa module, and two MOSFETs and three resistors to drive a speaker and the TFT backlight. Aside from connectors, the switches, and the submodules themselves, that’s all of the external circuitry.

The arrangement of two USB connectors, type C for power and micro-USB for data, is an interesting aspect of the connector / module placement. He plans to add an Ethernet module in the future, and issue some more revisions to fix small errors and to make the front panel fit more sizes of displays. We wonder if a battery module add-on is in the works, as well.

If you recognize [bobricius], that’s because his previous ARMACHAT handheld LoRa messenger project was among the Hackaday Prize Community Vote (Bootstrap) winners last year. We think tiny keyboards may be an obsession for him — indeed, he freely admits to being blinded by his own enthusiasm. Check out his mini (Pi)QWERTY USB keyboard from 2018, for example. Thanks to [Itay] for bringing this project to our attention via the Hackaday tip line.

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LoRa Messenger Does Its Best BlackBerry Impression

While the de facto smartphone design ultimately went in a different direction, there’s no denying the classic BlackBerry layout offered some compelling advantages. It was a gadget primarily designed to send and receive emails and text messages, and it showed. So is it really any wonder [MSG] would build his pocket-sized LoRa messengers in its image?

Of course, he did have some help. The communicators use the Keyboard FeatherWing by [arturo182], which puts a surplus BlackBerry Q10 keyboard on a custom PCB designed to accept a board from Adafruit’s Feather collection. [MSG] ended up pairing his with a Feather M4 because he wanted to work with CircuitPython, with a 900 MHz LoRa FeatherWing along for the ride. He notes that switching his code over to Arduino-flavored C would allow him to use the Feather M0 that features integrated LoRa; a change that would allow him to make the gadget a bit thinner.

Inside the 3D printed enclosure, He’s made room for a 3.7 V 1800 mAh pouch battery that should provide plenty of runtime. There’s also an external antenna with a uFL pigtail for connecting to the radio. The case is held together with heat-set inserts, which should make it more than robust enough to handle a few adventures.

[MSG] says slight variations in hardware versions means his STLs might need a little tweaking to fit your components, and warns that his code is basically just a mashup of examples he found online, but he’s still sharing the goods for anyone who wants to reach out and touch someone without all that pesky infrastructure in the way.

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Building A Pocket Sized Python Playground

Like many of us, [Ramin Assadollahi] has a certain fondness for the computers of yesteryear. Finding his itch for nearly instant boot times and bare metal programming weren’t being adequately scratched by any of his modern devices, he decided to build the PortablePy: a pocket-sized device that can drop him directly into a Python prompt wherever and whenever the urge hits him.

The device is powered by the Adafruit PyPortal Titano, which combines a ATSAMD51J20, ESP32, an array of sensors, and a 3.5″ diagonal 320 x 480 color TFT into one turn-key unit. The PyPortal is designed to run CircuitPython, but the scripts are usually dropped on the device over USB. That’s fine for most applications, but [Ramin] wanted his portable to be usable without the need for a host computer.

For a truly mobile experience, he had to figure out a way to bang out some Python code on the device itself. The answer ended up being the M5Stack CardKB, a tiny QWERTY board that communicates over I2C. Once he verified the concept was sound, he wrote a simple file management application and minimal Python editor that could run right on the PyPortal.

The final step was packaging the whole thing up into something he could actually take off the bench. He designed a 3D printed clamshell case inspired by the classic Game Boy Advance SP, making sure to leave enough room in the bottom half to pack in a charging board and LiPo pouch battery. He did have to remove some of the connectors from the back of the PyPortal to get everything to fit inside the case, but the compact final result seems worth the effort.

While an overall success, [Ramin] notes there are a few lingering issues. For one thing, the keyboard is literally a pain to type on. He’s considering building a custom keyboard with softer buttons, but it’s a long-term goal. More immediately he’s focusing on improving the software side of things so its easier to write code and manage multiple files.

It sounds like [Ramin] isn’t looking to compromise on his goal of making the PortablePy completely standalone, but if your convictions aren’t as strong, you could always connect a device like this up to your mobile to make things a bit easier.

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A Pocket Retro Computer Anyone Can Build

Not satisfied with any of the DIY retro computer kits on the market, [Leonardo Leoni] decided to make his own. Built using only the finest through-hole technology and powered by the ATmega328 microcontroller, his diminutive 8-bit computer is easy to build and even easier to develop for. Whether you’re looking to hone your BASIC skills or play some Zork on the bus, this little computer looks like a great project for anyone who has a soft spot for computing’s simpler days.

All things considered, using this tiny machine looks like it would be relatively pleasant. [Leonardo] is using a common SH1106 OLED display, and there’s a full QWERTY keyboard (with number row) done up with tactile momentary buttons. There’s very few passive components involved in the build, which is sure to be appealing to new players; especially after they’ve finished soldering all those switches to the board.

On the software side, [Leonardo] says he leaned heavily on open source projects to get his machine up and running. Beyond the hardware drivers for things like the display, he specifically calls out the Tiny Basic and Tiny Lisp Computer projects for their code. If small-scale programming isn’t your style, the machine is compatible with the Arduino IDE so you can easily throw something else on it. If you’ve ever dreamed of a QWERTY Arduboy, this might be your chance.

From the way [Leonardo] describes the computer, which he calls the Cobalt 3, we get the impression a commercial kit might be in the cards. We hope the community shows enough interest to make it happen. After all, not everyone was able to make it to Hackaday Belgrade 2018 to get their own pocket retro computer.

A Fantastic Raspberry Pi Handheld Just Got Better

Last year, we brought you word of the MutantC by [rahmanshaber]. The Raspberry Pi handheld was more than a little inspired by the classic T-Mobile Sidekick, with a sliding display and physical QWERTY keyboard. The design was a little rough around the edges and missing a few key features, but it was clear the project had a lot of potential.

Today, we’re happy to report that [rahmanshaber] has officially released MutantC_v2. It looks like the new version of this handheld, perhaps more properly categorized as a ultra-mobile PC (UMPC), successfully addresses a number of the shortcomings found in the original; so if you held off on building one last year, you might want to start warming up the 3D printer now.

The major improvement over the original is the inclusion of a battery, which makes the device truly mobile. This was something that we mentioned [rahmanshaber] was working on back when he released the first version, as it was easily the most requested feature from the community. We certainly wouldn’t say a miniature handheld computer is completely useless if it has to stay tethered, but there’s no arguing that being able to take it on the go is ideal.

This upgraded version of the design now officially supports the Raspberry Pi 4 as well, which previously [rahmanshaber] was advising against due to overheating concerns. Slotting in the latest-and-greatest edition of every hacker’s favorite Linux single board computer will definitely kick things up a notch, though we imagine the older and less power hungry iterations of the Pi will be plenty for the sort of tasks you’re likely to be doing on a gadget like this.

If you like the idea of having a diminutive Linux computer within arm’s reach of your bench but aren’t necessarily committed enough to build something like the MutantC, there are certainly simpler designs you can get started with.

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