handhelds hacks

407 Articles

Shelved Kindle Gets New Life As Weather Display

February 27, 2025 by 8 Comments

In the rush to always have the latest and greatest, it’s not uncommon that perfectly serviceable hardware ends up collecting dust in a drawer somewhere. If you’ve got an old Kindle laying around, you may be interested in this write-up from [Hemant] that shows a practical example of how the popular e-reader can be pushed into service as a weather dashboard.

The first step is to jailbreak the Kindle, providing the user with root access to the device. From there the Kindle Unified Application Launcher (KUAL) is installed along with USBNetwork which allows you to connect to the reader over SSH. With root access and a network connection, the real project of converting it to a weather dashboard begins. [Hemant] split the project into two parts here, a Node.js server that scrapes weather data from the internet and converts it into an image, and a client for the Kindle that receives this image for display.

The Kindle has a number of quirks and issues that [Hemant] covers as well, including handling image ghosting on the e-ink display as well as a problem where the device will hang if the Internet connection is lost. For those with jailbroken Kindles that want to put their devices back into useful service, this is an excellent guide for getting started and [Hemant] also provided all of the source code on the project’s GitHub page.

There has been a long tradition of using Kindles for things other than e-readers, and even devices with major hardware problems can still have useful life in them thanks to this project which allows the e-ink display to have a second life on its own.

BlackBerry Keyboard Makes This Handheld Pi Stand Out

February 25, 2025 by 14 Comments

In the decade or more since small inexpensive Linux-capable single board computers such as the Raspberry Pi came to the mainstream, many a hardware hacker has turned their attention to making a portable computer using one. With such a plethora of devices having been made one might think that the Pi handheld was a done deal, but every so often along comes a new one of such quality to re-ignite the genre. So it is with [Taylor Hay]’s BlackberryPi Handheld. As you might guess from the name, it uses a BlackBerry keyboard along with a square LCD screen to create a beautifully executed Pi handheld in an almost GameBoy-like form factor.

It starts with a beautifully designed and executed case that holds a Pi and a Pimoroni HyperPixel screen. Unexpectedly this is a full-size Pi, we think a Pi 4. The keyboard is a USB enhanced Blackberry module which also has the famous trackpad, and there’s a bezel on the front to protect the screen. The power meanwhile comes from three 18650 cells inside the back of the case, with a power bank PCB. The surprise here is how simple he’s made it by careful choice of modules, the usual rats-nest of wires is missing.

The files are available so you can make your own, and he’s actively encouraging people to remix and improve it. We like this project, a lot, and after you’ve seen the video below the break, we think you will too. Oddly, this isn’t the first time we’ve seen someone try this combination.

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The Perfect Pi Pico Portable Computer

February 22, 2025 by 25 Comments

[Abe] wanted the perfect portable computer. He has a DevTerm, but it didn’t quite fit his needs. This is Hackaday after all, so he loaded up his favorite CAD software and started designing. The obvious choice here would be a Raspberry Pi. But [Abe] didn’t want to drop in a Linux computer — he was going for something a bit smaller.

An RP2040 Pico would be a perfect fit. Driving a display with the Pico can be eat a lot of resources though. The solution was a PicoVision from Pimoroni. PicoVision uses two RP2040 chips. One drives an HDMI port, while the other is free to run application software. This meant a standard HDMI screen could be used.

The keyboard was a bit harder. After a lot of searching, [Abe] found an IR remote designed for smart TVs. The QWERTY keyboard was the perfect size but didn’t have an interface he could use. He fixed that with an adapter PCB including an I2C GPIO expander chip. A bit of I2C driver software later, and he had a working input keyboard.

Hardware doesn’t do anything without software though. The software running on the handheld is called Slime OS, and the source is available at [Abe’s] GitHub. It’s a launcher, with support for applications written in python. [Abe] has a few basic demos working, but he’s looking for help to get more features up and running.

Although it wasn’t quite what [Abe] was after, our own [Donald Papp] came away fairly impressed when he gave the DevTerm a test drive back in 2022. Something to consider if you’re looking for a Linux handheld and not quite ready to build one yourself.

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Game Bub Plays ROMs And Cartridges

February 15, 2025 by 10 Comments

With today’s technology, emulating video game consoles from the 90s or before is trivial. A Raspberry Pi and a controller of some sort is perhaps the easiest and simplest way to go to get this job done, but to really impress the masses some extra effort is required. This handheld from [Eli] called the Game Bub not only nails the appearance and feel of the first three generations of Nintendo handhelds but, thanks to its FPGA, can play not only ROMs but the original game cartridges as well.

As [Eli] notes, the FPGA is not strictly necessary for emulation, but does seem to be better at interfacing with physical hardware like controllers and game cartridges. For this task an Xilinx XC7A100T with integrated memory was chosen, with a custom PCB supporting the built-in controller, speaker, a rechargeable lithium battery, and a 480×320 display (that had to be rotated out of portrait mode). An SD Card reader is included for any ROM files, and there’s also a ESP32-S3 included to give the handheld WiFi and Bluetooth capabilities, with future plans to support the communications protocol used by the Game Boy Advance Wireless Adapter.

There are a few other features with the Game Bub as well, including the ability to use an authentic link cable to communicate with the original Game Boy and Game Boy Color, and a Switch-like dock that allows the Game Bub to be connected to an external monitor. It’s also open source, which makes it an even more impressive build. Presumably it doesn’t include the native ability to dump cartridges to ROM files but you don’t need much more than a link cable to do that if you need to build your ROM library.

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A Tiny Computer With A 3D Printed QWERTY Keyboard

February 11, 2025 by 10 Comments

The ESP32 family are the microcontrollers which just keep on giving, as new versions keep them up-to-date and plenty of hackers come up with new things for them. A popular device is a general purpose computer with a QWERTY keypad, and the latest of many we’ve seen comes from [StabbyJack]. It’s a credit card sized machine whose special trick is that its keyboard is integrated in the 3D printing of its case. We’ve seen rubber membranes and push in keys, but this one has flexible print-in-place keys that line up on the switches on its PCB.

It’s not complete yet but the hardware appears to be pretty much there, and aside from that keyboard it has an ESP32-S3 and a 1.9″ SPI LCD. When finished it aims for an ambitious specification, with thermal camera and time-of-flight range finder hardware, along with an OS and software to suit. We like it a lot, though we suspect it might be a little small for our fingers.

If you like this project you may appreciate another similar one, and perhaps your version will need an OS.

A Closer Look At The Tanmatsu

February 4, 2025 by 27 Comments

A few weeks ago we brought you news of a new palmtop computer for hackers, powered by the new Espressif ESP32-P4 application processor. The Tanmatsu (Japanese for “Terminal”) is a compact handheld device with a QWERTY keyboard and an 800×480 DSI display, and while it currently exists at the final prototype stage there is a pre-order page upon which you can reserve an early production model for yourself. We’ve been lucky enough to be invited to give one a close-up inspection, so it was time to hot-foot it on the train to a Dutch hackerspace in order to bring you a preview.

A Little History, And First Impressions

The Tanmatsu, held in both hands.
Recesses in the case fit well against the hands.

Before looking at the device, it’s time for a little history. The Tanmatsu has its origin in badge.team, the Netherlands-based group that has produced so many European event badges over the years, and it was destined to eventually become the badge for the upcoming WHY2025 hacker camp. As sometimes happens in any community there has been a significant difference of opinion between the event orga and the badge.team folks that it’s inappropriate to go into here, so now it exists as a standalone project. It’s destined to be open-source in its entirety including hardware and software (and we will hold them to that, never fear), but because of the events surrounding its conception the full repositories will be not be made public until some time late in the summer.

Picking the Tanmatsu up and holding it, it’s a rectangular slab a bit larger and thicker than a CD case with that QWERTY keyboard and display on its front face, an array of ports including an SMA socket for a LoRA antenna on its sides, and an expansion connector on its rear. It has a sandwich construction, with a PCB front face, a 3D printed spacer, the PCB itself, and a 3D printed back cover all held together with a set of screws. The recesses on its bottom edge and the lower halves of the sides locate neatly with fingers and thumbs when it’s held in two hands for two-thumb typing. The keyboard is a silicone moulding as is common on this type of device, and while the keys are quite small it was not difficult to type on it. The display meanwhile feels of much higher quality than the SPI parts previously seen on badges. Continue reading “A Closer Look At The Tanmatsu” →

Casio Calculator Gets New Keyboard

February 1, 2025 by 5 Comments

What do you do with a circa 1985 Casio FX-451 calculator with a bad keyboard? Well, if you are [Poking Technology], you transplant the inside of the calculator to a new custom keyboard. There are two videos that cover the process in detail, which you can watch below.

The calculator has a unique design. It looks like a simple calculator in a wallet. But the wallet opens to reveal an extended keyboard with all the scientific features onboard. Unsurprisingly, the membrane keys didn’t survive over four decades. Disassembling the unit was a challenge. Soldering wires to the keyboard lines was further complicated by the fact that some of the lines are on the back of the PCB and pass through to the top under the main IC.

The new keyboard is quite a bit larger than the original, making this more of a desk calculator, but that also means you can use high-quality keys. We’d love to see a 3D printed case to wrap it all up, but the bare PCB look has its charms, too.

If you can’t understand how [Poking] can love a calculator so much, you probably never owned an HP-41C, either. Of course, our retro calculator dreams also include Star Trek.

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