Turning Old Cellphones Into SBCs

April 8, 2025 by Elliot Williams 33 Comments

[David] sent us a tip about a company in Belgium, Citronics, that is looking to turn old cellphones into single-board computers for embedded Linux applications. We think it’s a great idea, and have long lamented how many pocket supercomputers simply get tossed in the recycling stream, when they could be put to use in hacker projects. So far, it looks like Citronics only has a prototyping breakout board for the Fairphone 2, but it’s a promising idea.

One of the things that’s stopping us from re-using old phones, of course, is the lack of easy access to the peripherals. On the average phone, you’ve got one USB port and that’s it. The Citronics dev kit provides all sorts of connectivity: 4x USB 2.0, 1x Ethernet 10/100M, and a Raspberry Pi Header (UART, SPI, I2C, GPIO). At the same time, for better or worse, they’ve done away with the screen and its touch interface, and the camera too, but they seem to be keeping all of the RF capabilities.

The whole thing runs Linux, which means that this won’t work with every phone out there, but projects like PostmarketOS and others will certainly broaden the range of usable devices. And stripping off the camera and screen has the secondary advantages of removing the parts that get most easily broken and have the least support from custom Linux distros.

We wish we had more details about the specifics of the break-out boards, but we like the idea. How long before we see an open-source implementation of something similar? There are so many cheap used and broken cellphones out there that it’s certainly a worthwhile project!

A design sketch of a partially disassembled candybar mobile phone. The enclosure is a clamshell of plastic that envelops the functional internals of the device and is illustrated to the right upper corner of the image, slightly overlapping the internals evoking the idea of the internals being inserted into the cover. The words "buttons part of the cover" are written toward the top with an arrow toward the numpad and "plastic shell with various design" is written toward the bottom with an arrow toward the translucent blue shell.

The Nokia Design Archive Is Open For Viewing

January 21, 2025 by Navarre Bartz 19 Comments

During the Cambrian Explosion of cellphone form factors at the turn of the millenium, Nokia reigned supreme. If you’d like to see what they were doing behind the scenes to design these wild phones, you’ll love the Nokia Design Archive from Aalto University.

Featuring images, presentations, videos and a number of other goodies (remember transparencies?), this collection gives us some in-depth insight into how consumer products were dreamed up, designed, and brought to market. Some projects require more reading between the lines than others as the Archive is somewhat fragmented, but we think it could still be an invaluable peek into product design, especially if you’re working on projects that you want to be usable outside of a hacker audience.

The Archive also includes approximately 2000 objects including many unreleased “unknown” models and prototypes of phones that actually did make it into the wild. While we’d love to get our hands on some of these devices IRL, having images with reference colors is probably the next best thing. Having replaced a number of smartphone screens, we hope more hackers take up the buttons and indestructible casing of these elegant devices for a more civilized age.

Thanks to [Michael Fitzmayer] for the tip! Be sure to checkout his work on Nokia N-Gage phones, including an SDK if you too love to taco talk.

When The EU Speaks, Everyone Charges The Same Way

December 30, 2024 by Jenny List 98 Comments

The moment everyone has been talking about for years has finally arrived, the European Union’s mandating of USB charging on all portable electronic devices is now in force. While it does not extend beyond Europe, it means that there is a de facto abandonment of proprietary chargers in other territories too. It applies to all mobile phones, tablets, digital cameras, headphones, headsets, game consoles, portable speakers, e-readers, keyboards, mice, portable navigation systems and earbuds, and from early 2026 it will be extended to laptops.

Hackaday readers will probably not need persuading as to the benefits of a unified charger, and truth be told, there will be very few devices that haven’t made the change already. But perhaps there’s something more interesting at work here, for this moment seals the place of USB-C as a DC power connector rather than as a data connector that can also deliver power.

Back in 2016 we lamented the parlous state of low voltage DC power standards, and in the time since then we’ve arrived at a standard involving ubiquitous and commoditised power supplies, cables, and modules which we can use for almost any reasonable power requirement. You can thank the EU for that mobile phone now having the same socket as its competitor, but you can thank the USB Implementers Forum for making DC power much simpler.

The Moondrop MIAD 01: A Smartphone With Balanced Audio Output

May 9, 2024 by Maya Posch 21 Comments

Over the past several years we have seen smartphones regrettably lose features which were once standard, such as FM radios, IR blasters, status LEDs, physical buttons, micro SD card slots, and of course headphone jacks. An interesting counterpoint here regarding the latter is the newly released Moondrop MIAD 01 smartphone.

As a relatively well-known manufacturer of audio equipment including in-ear monitors (IEMs), the announcement of a smartphone came out of left field, but the specifications make sense. Of particular interest are the dual audio jacks: one 3.5 mm TRRS and one 4.4 mm balanced TRRS, making it a good match for high-end headphones that support balanced audio.

While the smartphone hardware is your average mid-range selection, featuring a MediaTek Dimensity 7050 SoC — its main selling point are the dual Cirrus Logic MasterHiFi DACs, that power the dual audio jacks. It’s also the reason behind the name: Mobile Internet Audio Device, or MIAD for short.

Given Moondrop’s audio enthusiast market, this tracks. These are people for whom the mere mentioning of ‘Bluetooth Audio’ or ‘USB-C-to-audio jack dongle’ is likely to evoke a less than favorable response.

In terms of software, Moondrop says the phone will offer a “native” Android 13 experience, which hopefully means it will be free from manufacturer-specific changes and bloatware. You’ll need to manually install Google Mobile Services though, as is often the case with Android devices that aren’t from the major players in the industry.

As reported by Android Authority, the MIAD 01 is available via select outlets for $399. Details like software updates remain to be clarified, but this might be the most over the top audio-centric smartphone we have seen so far. It definitely gives Sony’s current range of Android-based Walkmans a run for their money, while even having phone functionality in the package.

Phone connected to the DIY LTE network playing a YouTube video, with antennas in the background

Building Your Own 4G LTE Base Station

March 3, 2024 by Arya Voronova 14 Comments

We’ve seen quite a few DIY 2G networks over the years, but the 4G field has been relatively barren. Turns out, there’s an open source suite called srsRAN that lets you use an SDR for setting up an LTE network, and recently, we’ve found a blog post from [MaFrance351] (Google Translate) that teaches you everything you could need to know if you ever wanted to launch a LTE network for your personal research purposes.

For a start, you want a reasonably powerful computer, a transmit-capable full-duplex software defined radio (SDR), suitable antennas, some programmable SIM cards, and a few other bits and pieces like SIM card programmers and LTE-capable smartphones for testing purposes. Get your hardware ready and strap in, as [MaFrance351] guides you through setting up your own base station, with extreme amounts of detail outlining anything you could get caught up on.

Continue reading “Building Your Own 4G LTE Base Station” →

An image of a smarphone sitting on a lightly-colored wooden table. It has a tan case surrounding it on the top 2/3, and a copper case holding a BlackBerry Q10 keyboard jutting out over the bottom of the phone.

FairBerry Brings The PKB Back To Your Smartphone

January 24, 2024 by Navarre Bartz 37 Comments

Missing the feel of physical keys on your phone, but not ready to give up your fancy new touchscreen phone? [Dakkaron] has attached a BlackBerry keyboard to a slightly more recent device.

Designed for the FairPhone 4, [Dakkaron]’s hack should be transferable to other smartphones as it connects to the phone over USB without any of that tedious mucking about with Bluetooth. There’s even a handy OpenSCAD-based generator to help you along in the customization process.

[Dakkaron] started with an Arduino Pro Micro-based implementation, but the most recent iteration uses a custom board that can be obtained partially-populated. Unfortunately, the Hirose connector for the keyboard isn’t available off-the-shelf, so you’ll have to solder that yourself if you’re planning to do this mod. Sounds like a perfect opportunity to practice your surface mount soldering skills!

If the Q10 keyboard looks familiar, it’s probably because it’s one of the most popular keyboards for small projects around here. Check out Regrowing a BlackBerry from the Keyboard Out or a LoRa Messenger with one. We’ve even seen them in a conference badge!

5Ghoul: The 14 Shambling 5G Flaws Used For Disruptive Attacks On Smartphones

December 13, 2023 by Maya Posch 5 Comments

A team of researchers from the ASSET Research Group in Singapore have published the details of a collection of vulnerabilities in the fifth generation mobile communication system (5G) used with smartphones and many other devices. These fourteen vulnerabilities are detailed in this paper and a PoC detailing an attack using a software defined radio (SDR) is provided on GitHub. The core of the PoC attack involves creating a malicious 5G base station (gNB), which nearby 5G modems will seek to communicate with, only for these vulnerabilities to be exploited, to the point where a hard reset (e.g. removal of SIM card) of the affected device may be required.

Hardware Setup for 5Ghoul PoC testing and fuzzer evaluation. (Credit: Matheus E. Garbelini et al., 2023)

Another attack mode seeks to downgrade the target device’s wireless connection, effectively denying the connection to a 5G network and forcing them to connect to an alternative network (2G, 3G, 4G, etc.). Based on the affected 5G modems, the researchers estimate that about 714 smartphone models are at risk of these attacks. Naturally, not just smartphones use these 5G modem chipsets, but also various wireless routers, IoT devices, IP cameras and so on, all of which require the software these modems to be patched.

Most of the vulnerabilities concern the radio resource control (RCC) procedure, caused by flaws in the modem firmware. Android smartphones (where supported) should receive patches for 5Ghoul later this month, but when iPhone devices get patched is still unknown.