Phone Hacks

222 Articles

Off-Grid OCR Server Powered By IPhone

May 31, 2026 by 8 Comments

Running an optical character recognition (OCR) server might sound like it would need some powerful hardware, like a rack-mounted, water-cooled machine, or at least a nice desktop or laptop. But if you have the time, anything could be used. [Hemant] has a long-running personal project that processes a lot of image data over a long time, and set up the OCR server on an iPhone 8 running entirely with solar power, rather than turn to more typical hardware.

Part of what makes this task feasible for low-powered hardware is Apple’s Vision framework, which uses machine learning to aid in things like character recognition (among other tasks). It will run on an iPhone just as easily as a Mac. The phone’s built-in battery already provides the first step of an off-grid setup. This build relies on a separate power bank to integrate the phone with the solar panel more easily. On the software side, [Hemant] reports that the true challenge wasn’t setting up the server as much as it was keeping the iPhone from sleeping or stopping his program from running full-time.

A system like this running off-grid, especially considering the costs of the solar panel and power bank, might seem counterproductive. But when comparing electricity costs for running the same software on his server, he estimates he saves about $10 per month with this setup, which has a payback of somewhere around 2-3 years. Not too bad for a phone that would have otherwise ended up in a landfill. Old phones can be surprisingly good choices for servers, too. It helps if they can run Linux, but plenty of phones will support server applications, even when running their native OS.

A phone running the XFCE desktop environment is placed on a desk, with a wireless keyboard in front of it.

Linux On Android Provides Inexpensive, Powerful Computing

May 26, 2026 by 62 Comments

In some parts of the world it’s common for cell service providers to sell new phones at a price significantly below market value, with the caveat that these phones are locked to that service provider alone. It’s questionable whether this practice is good for consumers, but as [Gabriel Broussard Korr] notes, it’s an opportunity for hackers: since it’s possible to run a Linux environment on these phones, they make an inexpensive source of quite powerful computing hardware.

In this case, [Gabriel] was using the Moto G Power 2024, which has 128 GB of storage, 12 GB of RAM, and costs less than $50 when carrier-locked. Rather than trying to install a mobile-oriented Linux distribution (such as postmarketOS), [Gabriel] installed Termux, a terminal emulator which provides a Linux environment within Android. Before doing this, he set up the phone and configured a number of settings for a better Linux experience. Since automatic updates can interfere with these settings, and since none of the provided settings effectively disable these, he used NetGuard to block Internet access from the updater app and from Google Play services.

The next step was to actually install Termux, as well as an X11 extension and an app which exposes an API for Termux. The desktop environment (XFCE in this case) was installed through Termux, and [Gabriel] wrote a shell script to go through the steps of starting it. XFCE worked well on mobile devices because of its full-desktop zoom capability. Even running Linux indirectly, the experience was smooth; [Gabriel] found that GIMP, Shotcut, and VS Code all performed well.

It’s not quite the same set of software, but we’ve previously featured a guide to setting up a similar Linux environment using Termux and AnLinux. Lindroid provides a similar containerized Linux environment; on the other hand, you can also use postmarketOS to make a server from an old phone.

Compact Calendar Display Reduces Phone Dependency

May 1, 2026 by 6 Comments

Phones can be distracting objects if you’re not an enlightened master of the mental arts. Even just reading an email or glancing at your calendar can get you caught up checking other apps and notifications and waste your time. [Paul Lagier] built a device to eliminate this problem by showing him critical information right on his desk.

The device is based around an off-the-shelf Waveshare ESP32 board which packs in a small 8×8 RGB LED matrix on one side. It’s a neat way to get an LED project up and running quickly, but [Paul] noted that it didn’t look that great out of the box. He had to experiment with some different solutions for diffusing the light, eventually wrapping the board in a 3D printed housing with a black grid to separate the light output from each LED to make a clear pixelated display.

The ESP32’s wireless connectivity comes in handy, because it’s able to query web services for [Paul’s] calendar and other useful data. The user interface is minimal—you merely flip the housing into a different orientation to display different information, relying on the onboard QMI8658 6-axis sensor. The main display shows [Paul’s] calendar in 15 minute blocks so he can keep track of meetings without having to open his phone. Shaking the device in this mode will display the events as scrolling text. There’s also an ambient mode that looks pretty, and a pairing mode for setting up the wireless connectivity.

The great thing about modern electronic hardware is that it’s very easy to produce productivity aids like this to suit your own lifestyle.

Continue reading “Compact Calendar Display Reduces Phone Dependency” →

USB-C Charger Juices Up 100 Devices At Once

April 30, 2026 by 15 Comments

Back when phones used to ship with chargers in the box, you’d get a plugpack that could charge one device. Aftermarket manufacturers eventually started making chargers with four or five ports which were great for travelling. But what if you wanted to charge even more devices? You might build something like this rig from [DENKI OTAKU].

The goal was to build a charger that could handle 100 devices at once. The charger is designed to charge devices at up to 1.5 amps. That’s no mean feat, as the device would have to be able to deliver 150 amps total when fully loaded. As for the actual design, though, it’s relatively simple. [DENKI OTAKU] simply built a simple USB-C charger PCB based around an off-the-shelf chip which has ten individual chargers on it, and stacked it up ten of those in a housing made out of aluminium extrusion. To deliver the current to run all these chargers, the rig got two massive switching power supplies to feed the charger array a massive amount of current. The open enclosure design here makes sense, in that it probably helps keep everything cool.

The only thing missing from the build video? A heavy-duty test. We’d love to see if it actually holds up under full load with 100 phones connected. We have some suspicions as to whether the traces on the PCBs would hold up under a continuous 15 amp load, for example. Still, if you wanted to provide phone charging en-masse at an event or similar, this kind of simple stacked design could be an easy way to go.

Phone chargers are still moving forward; the last big leap was the adoption of GaN technology. Video after the break.

Continue reading “USB-C Charger Juices Up 100 Devices At Once” →

Payphone Tag Is Australia’s New National Sport

April 28, 2026 by 44 Comments

Australia’s payphones are an iconic part of the national landscape, even if they’re not as important as they once used to be. However, they’re having a resurgence of late, in part thanks to a new national pastime—the sport of Payphone Tag!

Created by [Alex Allchin], the game is simple. To play, you first sign up on the website and get your emoji and 5-digit PIN. You then go out and find a payphone, dial the Payphone Tag number, and enter your PIN when prompted. This lets you “capture” the phone, raising your score in the game. If a phone is already captured, no matter—just head out there, dial the number, and key in your own PIN to steal it. You can also push your score even higher by capturing three payphones in a triangle on the map to get bonus points.

It’s a fun geospatial game that’s also free to play, because Telstra made payphone calls free back in 2022. It might cost you a bit to get out to some phones, but there are plenty you can reach with the aid of free public transport at the moment, anyway. Protip—at the time of writing, there are a ton of easy captures to be had on Kangaroo Island. It might just cost you a pretty penny to get out there. Have at it!

We’d love to see some stats from Telstra as to whether this is making a dent in overall payphone usage rates. In any case, there were 800 players in the last 7 days and a full 36,640 captures so far, so a lot is happening out there. We fully expect to see this concept spread to other nations in turn, though it might be less attractive in places where you still need to dig out a coin to make a call.

We’ve featured a few payphone hacks over the years. If you’re doing something rad with these telecommunication devices of yesteryear, we’d love to hear about it on the tipsline.

Hear Ye, Hear Ye! The Magic Of The Scroll-Like Phone Which Wast Not!

April 7, 2026 by 11 Comments

When LG left the smartphone market, quite a number of strange devices were left behind. While some, like the Wing, made it to consumers, others did not. The strangest of these would have to be their rollable phone concept; a device which would expand by unrolling a portion of the screen like a scroll. This never made it to market, but one managed to make its way to [JerryRigEverything’s] workbench, and we are fortunate enough to see the insides of this strange device. 

There are a few interesting tidbits about the device before even entering the device. Very clearly this phone was ready to be sold, with a tidy user interface for expanding the display, and even animated wallpapers which expand with it. The display, when rolled onto the back of the device, sits behind a glass cover to keep it protected from debris, and can be used to take selfies with the larger sensors of the rear facing cameras. You can also see a bit of the track that the screen rolls on, hinting at what lies inside.

Continue reading “Hear Ye, Hear Ye! The Magic Of The Scroll-Like Phone Which Wast Not!” →

pi 1990s brick phone

No More Paperweight: This Vintage Brick Phone Is Back Online

March 13, 2026 by 20 Comments

Remember those brick cellphones in the 1990s? They were comically large by today’s standards. These phones used the 1G network to communicate and, as such, have been unusable for decades now. However [Alan Boris] has resurrected this classic phone to operate today.

Originally costing as much as today’s top-of-the-line phones, but instead of weighing just a few ounces this classic Motorola DynaTAC 8000 Classic 2 tips the scales at a hefty 1.5 lbs. [Alan Boris] decided to not just bring the electronics back to life, but to even stuff a modern cellphone inside it to make it fully functional. Given the size of this phone, finding room for the new innards wasn’t much of a challenge. In fact, after the retrofit there was less in the phone than when it started life.

Using a perfboard and some tactile switches he was able to sense the button presses on the phone’s keypad and relay those to a Raspberry Pi Pico 2. The Pico in turn drove a small color LCD to replicate the original screen and controlled a pair of ADG729 boards used to dial the BM10 cellphone within this cellphone. The BM10 is a cellphone about the size of a 9V battery, making it easy to put inside the DynaTAC and bring the handset back to the modern cellular network.

Thanks [Alan Boris] for the tip! Be sure to check out our other cellphone hacks as well as some of our other retrofit hacks.

Continue reading “No More Paperweight: This Vintage Brick Phone Is Back Online” →