cellphone

94 Articles

Turning Old Cellphones Into SBCs

April 8, 2025 by 35 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 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.

Schematics, For A Modern Flagship Phone

February 7, 2024 by 36 Comments

The mobile phone is an expensive and often surprisingly fragile device, whose manufacturers are notorious for making them as difficult to repair as possible. Glued-together cases and unreplaceable batteries abound, and technical information is non-existent. But amongst all that there’s one manufacturer with a different approach — Fairphone. Case in point, they’ve released the full service guide including schematics for their flagship Fairphone 5.

Fairphone’s selling point is the repairability and internal accessibility of their products and of course they’ve made hay with this as a marketing opportunity. But aside from that, it’s a fascinating chance to look in-depth at a modern smartphone from the inside out. We see the next-level PCB layout and how everything is so neatly packed into the minimum space, all without resorting to a heat gun.

It’s great to have another hackable phone, and fair play to Fairphone for releasing all this stuff, but perhaps the most interesting part from where we’re sitting is how and where this phone is being sold. There have been hackable phones before, for many the Pinephone will spring to mind, but they have always been sold to an audience who buy to hack. Here in Europe where this is being written, the Fairphone is being sold as a consumer device. It won’t shake Apple or Samsung from their perches, but for a hackable device to be so generally available to those who wish to do things with it can never be a bad thing.

We took a quick look at Fairphone back in 2015, when they launched.

Mobile Phones And The Question Of Declining Sperm Quality

November 28, 2023 by 105 Comments

In a world increasingly reliant on technology, a pressing question arises: can our dependence on gadgets, particularly mobile phones, be affecting our health in unexpected ways? A growing body of research is now pointing towards a startling trend – declining sperm quality in the human population – with mobile phones emerging as a potential culprit.

Recent studies have been sounding the alarm over a noticeable decline in sperm counts and quality across the globe. This decline isn’t just about quantity; it’s about the vitality, motility, and overall health of sperm cells. The implications of this trend are profound, affecting fertility rates and possibly even the long-term viability of populations. The situation is murky and complicated, but new studies suggest that cellular phones could have a role to play.

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LTE Sniffer Ferrets Out Cellular Communications

May 18, 2023 by 8 Comments

LTE networks have taken over from older technologies like GSM in much of the world. Outfitted with the right hardware, like a software defined radio, and the right software, it’s theoretically possible to sniff some of this data for yourself. The LTESniffer project was built to do just this. 

LTESniffer is able to sniff downlink traffic from base stations using a USRP B210 SDR, outfitted with two antennas. If you want to sniff uplink traffic, though, you’ll need to upgrade to an X310 with two daughterboards fitted. This is due to the timing vagaries of LTE communication. Other solutions can work however, particularly if you just care about downlink traffic.

If you’ve got that hardware though, you’re ready to go. The software will help pull out LTE signals from the air, though it bears noting that it’s only designed to work with unencrypted traffic. It won’t help you capture the encrypted communications of network users, though it can show you various information like IMSI numbers of devices on the network. Local regulations may prevent you legally even doing this, and if so, the project readme recommends setting up your own LTE network to experiment with instead.

Cellular sniffing has always been somewhat obscure and arcane, given the difficulty and encryption involved, to say nothing of the legal implications. Regardless, some hackers will always pursue a greater knowledge of the technology around them. If you’ve been doing just that, let us know what you’re working on via the tipsline.

Plan To Jam Mobile Phones In Schools Is Madness

March 24, 2023 by 329 Comments

Mobile phones in schools. If you’re a teacher, school staffer, or a parent, you’ve likely got six hundred opinions about this very topic, and you will have had six hundred arguments about it this week. In Australia, push has come to shove, and several states have banned the use of mobile phones during school hours entirely. Others are contemplating doing the same.

In the state of New South Wales, the current opposition party has made it clear it will implement a ban if elected. Wildly, the party wants to use mobile phone jamming technology to enforce this ban whether students intend to comply or not. Let’s take a look at how jammers work in theory, and explore why using them in schools would be madness in practice.

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A grey smartphone sits inside a sleeve made of light brown wood veneer and a black felt interior.

Wooden Smartphone Sleeve Keeps You On Task

January 31, 2023 by 2 Comments

Smartphones are amazing tools, but sometimes they can be an equally amazing time suck. In an effort to minimize how much precious time goes down the drain, [Lance Pan and Zeynep Kirmiziyesil] decided to make a functional and beautiful smartphone sleeve to keep you on task.

Most modern smartphones have some form of Do Not Disturb mode available, but having the phone visible can still be an invitation for distraction. By tucking the phone into an accessible but less visible sleeve, one can reduce the visual trigger to be on the phone while keeping it handy in the even of an emergency.

Once in the sleeve, the NFC tag sandwiched between the felt and wood veneer triggers an automation to put the phone into Do Not Disturb mode. This hack looks like something that you could easily pull off in an afternoon and looks great which is always a winning combination in our book.

To see some more focus-oriented hacks, checkout the Pomodachi or this Offline E-Paper Typewriter.