cellphone

88 Articles

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.

2022 Hackaday Supercon: Joe [Kingpin] Grand Keynote And Workshops Galore

October 25, 2022 by 6 Comments

It’s our great pleasure to announce that Joe [Kingpin] Grand is going to be our keynote speaker at the 2022 Supercon!

If you don’t know Joe, he’s a hacker’s hacker. He’s behind the earliest DEFCON electronic badges, to which we can trace our modern #badgelife creative culture. He was at the l0pht when it became the most publicly visible hackerspace in the USA, at the dawn of what we now think of as cybersecurity. And moreover, he’s a tireless teacher of the art of hardware hacking.

Joe’s talk at DEFCON 22 about reverse engineering PCBs on a hacker budget is on our top-10 must watch playlist, and his JTAGulator debug-port enumeration device has been present at the start of countless hacking sessions. But again, it’s his enthusiasm for creating, his inspiring “what if I poke at this thing this way?” attitude, and overwhelming hacker spirit that make Joe a long-overdue speaker at Supercon! Continue reading “2022 Hackaday Supercon: Joe [Kingpin] Grand Keynote And Workshops Galore” →

GGWave Sings The Songs Of Your Data

July 6, 2022 by 11 Comments

We’re suckers for alternative data transmission methods, and [Georgi Gerganov]’s ggwave made us smile. At its core, it’s doing what the phone modems of old used to do – sending data encoded as different audio tones. But GGwave does this with sophistication!

It splits the data into four-bit chunks, and uses 16 different frequency offsets to represent each possible value. But for each chunk, these offsets are added to one of six different base frequencies, which allows the receiving computer to tell which chunk it’s in. It’s like a simple framing concept, and it makes the resulting data sound charmingly like R2-D2. (It also uses begin and end markers to be double-sure of the framing.) The data is also sent with error correction, so small hiccups can get repaired automatically.

What really makes ggwave shine is that it’s ported to every platform you care about: ESP32, Arduino, Linux, Mac, Windows, Android, iOS, and anything that’ll run Python or JavaScript. So it’ll run in a browser. There’s even a GUI for playing around with alternative modulation schemes. Pshwew! This makes it easy for a minimalist microcontroller-based beeper button to control your desktop, or vice-versa. An ESP32 makes for an IoT-style WiFi-to-audio bridge. Write code on your cell phone, and you can broadcast it to any listening microcontroller. Whatever your use case, it’s probably covered.

Now the downside. The data rate is slow, around 64-160 bits per second, and the transmission is necessarily beepy-booopy, unless you pitch it up in to the ultrasound or use the radio-frequency HackRF demo. But maybe you want to hear when your devices are talking to each other? Or maybe you just think it’s cute? We do, but we wouldn’t want to have to transmit megabytes this way. But for a simple notification, a few bytes of data, a URL, or some configuration parameters, we can see this being a great software addition to any device that has a speaker and/or microphone.

Oh my god, check out this link from pre-history: a bootloader for the Arduino that runs on the line-in.

Continue reading “GGWave Sings The Songs Of Your Data” →

How A Smartphone Is Made, In Eight “Easy” Blocks

May 9, 2022 by 21 Comments

The smartphone represents one of the most significant shifts in our world. In less than thirteen years, we went from some people owning a dumb phone to the majority of the planet having a smartphone (~83.7% as of 2022, according to Statista). There are very few things that a larger percentage of people on this planet have. Not clean water, not housing, not even food.

How does a smartphone work? Most people have no idea; they are insanely complicated devices. However, you can break them down into eight submodules, each of which is merely complex. What makes them work is that each of these components can be made small, at massive economies of scale, and are tightly integrated, allowing easy assembly.

So without further ado, the fundamental eight building blocks of the modern cellphone are: the application processor, the baseband processor, a SIM card, the RF processor, sensors, a display, cameras & lenses, and power management. Let’s have a look at them all, and how they fit together.

Continue reading “How A Smartphone Is Made, In Eight “Easy” Blocks” →

Monitor Space Weather And The Atmosphere With Your Cellphone!

April 4, 2022 by 9 Comments

Above our heads, the atmosphere is a complex and unpredictable soup of gasses and charged particles subject to the influence of whatever the Sun throws at it. Attempting to understand it is not for the faint-hearted, so it has for centuries been the object of considerable research. A new project from the European Space Agency and ETH Zurich gives the general public the chance to participate in that research in a small way, by crowdsourcing atmospheric data gathering to a mobile phone app. How might a mobile phone observe the atmosphere? The answer lies in their global positioning receivers, which can track minute differences in the received signals caused by atmospheric conditions. By gathering as much of this data as possible, the ESA scientists will gain valuable insights into atmospheric conditions as they change across the globe.

The app requires an Android phone equipped with a dual frequency satnav receiver, and having been duly installed on the trusty Hackaday Motorola it in turn started picking up all the different constellations of satellites. The instructions are to leave it somewhere such as a windowsill with an unobstructed view of the sky and move it as little as possible, to which we’d add clicking the “Log in background” button and connectign a charger. There’s a promise that uploaders can win prizes, so aside from contributing to scientific discovery there might be an unexpected benefit. More details on the app can be found here, meanwhile many readers will know that this isn’t the only crowdsourced atmospheric data gathering effort.

Replaceable Batteries Are Coming Back To Phones If The EU Gets Its Way

March 30, 2022 by 150 Comments

Back in the day, just about everything that used a battery had a hatch or a hutch that you could open to pull it out and replace it if need be. Whether it was a radio, a cordless phone, or a cellphone, it was a cinch to swap out a battery.

These days, many devices hide their batteries, deep beneath tamper-proof stickers and warnings that state there are “no user serviceable components inside.” The EU wants to change all that, though, and has voted to mandate that everything from cellphones to e-bikes must have easily replaceable batteries, with the legislation coming into effect as soon as 2024.

Continue reading “Replaceable Batteries Are Coming Back To Phones If The EU Gets Its Way” →

Here’s How Those Battery-Free Flashing Phone Stickers Worked

February 26, 2022 by 25 Comments

The late 90s and early 2000s were a breakout time for mobile phones, with cheap GSM handsets ushering in the era in which pretty much everybody had a phone. Back then, a popular way to customize one’s phone was to install a sticker that would flash when the phone rang. These required no batteries or any other connection to the phone, and [Big Clive] has dived in to explain how they worked. 

The simple schematic of the flashing sticker circuit. The flashing was generated by the pulses of RF energy from the smartphone.

It’s an old-fashioned teardown that requires a bit of cutting to get inside the sticker itself. A typical example had three LEDs in series for a total voltage drop of around 7V, hooked up to two diodes and a PCB trace antenna. A later evolution used raw unpackaged components bonded to the PCB. Future versions went down to a single diode, using the LEDs to serve as the second. The basic theory was that the PCB traces would pick up RF transmitted by the phone when a call was coming in, lighting the LEDs.

In the 2G era, the freuqencies used were on the order of 300 MHz to 1.9GHz. A combination of the change in frequencies used by modern phone technology and the lower transmit powers used by handsets means that the stickers don’t work properly with modern phones according to [Big Clive].

Incidentally, you might like to consider running your own old-school cellphone network. Video after the break.

Continue reading “Here’s How Those Battery-Free Flashing Phone Stickers Worked” →