phone

113 Articles

A Mobile Phone From 1985

May 25, 2023 by 6 Comments

It might seem quaint through the lends of history we have the luxury of looking through, but in the mid 1980s it was a major symbol of status to be able to communicate on-the-go. Car phones and pagers were cutting-edge devices of the time, and even though there were some mobile cellular telephones, they were behemoths compared to anything we would recognize as a cell phone today. It wasn’t until 1985 that a cell phone was able to fit in a pocket, and that first device wasn’t just revolutionary because of its size. It made a number of technological advancements that were extremely impressive for its time, and [Janus Cycle] takes us through some of those in this teardown video.

The Technophone came to us from Great Britain by way of a former Ericsson engineer named Nils Mårtensson. It was able to achieve its relatively small stature using a surface-mount PCB, which was a cutting-edge manufacturing process for the time. Not only did it use surface-mount components and boards, but the PCB itself has 12 layers and two sides and hosts two custom Technophone chips. The phone is relatively modular as well, with the screen, battery pack, and other components capable of easily disconnecting from the main board. Continue reading “A Mobile Phone From 1985” →

Old Czech Telephone Teardown Is Beautiful Purposeful Art

April 18, 2023 by 16 Comments

The 20th century saw everything from telephones to computers become mainstream. Many of these devices were beautifully designed in the mid-century period, something that’s hard to say about a lot of today’s cheaper technology. [John Graham-Cumming] has shown us one exquisite example, with his teardown of a simple Czech telephone.

The model in question is a DS3600 telephone built by Tesla Stropkov in the early 1980s. Despite this, it’s a design that looks like it hails more from the 1960s based on its smooth curves and rounded features. It’s a rotary dial phone, though a push-button version was also produced.

Inside the phone is a simple single-sided PCB clearly marked out with a tidy silkscreen. The ringer and a few capacitors make up the bulk of the circuitry inside the base, along with the rotary dial. The handset itself plays host to most of the other componentry, including the mystery “WNB 068 hybrid circuit” which [John] couldn’t positively identify.

It’s great to get a look inside vintage hardware and see how things were done in yesteryear. It’s particularly funny to think about how simple telephones used to be in contrast to today.

[Thanks to Saint Aardvark for the tip!]

Bicopter Phone Case Might Be Hard To Pocket, But Delivers Autonomous Selfies

February 10, 2023 by 8 Comments

Remember that “PhoneDrone” scam from a while back? With two tiny motors and props that could barely lift a microdrone, it was pretty clearly a fake, but that doesn’t mean it wasn’t a pretty good idea. Good enough, in fact, that [Nick Rehm] came up with his own version of the flying phone case, which actually works pretty well.

In the debunking collaboration between [Mark Rober], [Peter Sripol], and the indispensable [Captain Disillusion], you’ll no doubt recall that after showing that the original video was just a CGI scam, they went on to build exactly what the video purported to do. But alas, the flying phone they came up with was manually controlled. While cool enough, [Nick Rehm], creator of dRehmFlight, can’t see such a thing without wanting to make it autonomous.

To that end, [Nick] came up with the DroneCase — a bicopter design that allows the phone to hang vertically. The two rotors are on a common axis and can swivel back and forth under control of two separate micro-servos; the combination of tilt rotors and differential thrust gives the craft full aerodynamic control. A modified version of dRehmFlight runs on a Teensy, while an IMU, a lidar module, and a PX4 optical flow sensor round out the sensor suite. The lidar and flow sensor both point down; the lidar is used to sense altitude, while the flow sensor, which is basically just the guts from an optical mouse, watches for translation in the X- and Y-axes.

After a substantial amount of tuning and tweaking, the DroneCase was ready for field tests. Check out the video below for the results. It’s actually quite stable, at least as long as the batteries last. It may not be as flexible as a legit drone, but then again it probably costs a lot less, and does the one thing it does quite well without any inputs from the user. Seems like a solid win to us.

Continue reading “Bicopter Phone Case Might Be Hard To Pocket, But Delivers Autonomous Selfies” →

Rotary Dial Number Pad Is The Perfect Prank For Retro-Phone Enthusiast

December 5, 2022 by 10 Comments

We’re not sure about the rest of you, but to us, a keyboard without a number pad all the way over to the right just seems kind of — naked? We might not be accountants, but there’s something comforting about having the keypad right there, ready for those few occasions when you need to enter numbers more rapidly than would be possible with the row of number keys along the top of the keyboard.

What we are sure about, though, is that rapid numeric keying is not what this rotary dial numpad keyboard is all about. In fact, it’s actually an April Fool’s prank [Squidgeefish] played on a retro-phone-obsessed coworker, and it worked out pretty well. Starting with an old telephone dial from what must be an exceptionally well-stocked parts bin, [Squidgeefish] first worked out the electrical aspects of interfacing the dial with a cheapo mechanical keyboard. It turns out that there’s a lot of contact bounce in those old dials, leading to some software hacks to keep the Arduino happy.

There was also a little hackery needed to stuff a USB hub into the keyboard, as well as literal hacking of the keyboard’s PCB. A 3D printed enclosure allows the rotary dial to nestle into the place where the regular numpad would be, and it looks pretty good. We also like forcing the issue by replacing the entire row of number keys with a single massive prank key.

While this was all for fun, there are a couple of cool tips here, like chucking a bit of printer filament in a Dremel tool to stir-weld parts together. And even though we’ve seen that parametric keycap generator before, it is pretty cool to see it in action.

A Raspberry Pi Phone For The Modern Era

October 10, 2022 by 43 Comments

While it might seem like mobile phones are special devices, both in their ease of use and in their ubiquity in the modern culture, they are essentially nothing more than small form-factor computers with an extra radio and a few specific pieces of software to run. In theory, as long as you can find that software (and you pay for a service plan of some sort) you can get any computer to work as a phone. So naturally, the Raspberry Pi was turned into one.

[asherdundas], the phone’s creator, actually found a prior build based around the Raspberry Pi before starting this one. The problem was that it was built nearly a decade ago, and hadn’t been updated since. This build brings some modernization to the antiquated Pi phone, and starts with a 3D printed case. It also houses a touchscreen and a GSM antenna to connect to the cell network. With some other odds and ends, like a speaker and microphone, plus a battery and the software to tie it all together, a modern functional Raspberry Pi phone was created, with some extra details available on the project page.

The phone has the expected features — including calling, texting, and even a camera. A small WiFi USB dongle allows it to connect to the Internet too, allowing it to do all of the internet browsing a modern smartphone might want to do. The only thing that it might be pretty difficult to do is install Android apps, and although there are ways to get Android apps working in Linux, it’s not always strictly necessary to have this functionality.

Touch Tone MIDI Phone And Vocoder Covers Daft Punk

September 6, 2022 by 3 Comments

[poprhythm]’s Touch Tone MIDI Phone is a fantastic conversion of an old touch tone phone into a MIDI instrument complete with intact microphone, but this project isn’t just about showing off the result. [poprhythm] details everything about how he interfaced to the keypad, how he used that with an Arduino to create a working MIDI interface, and exactly how he decided — musically speaking — what each button should do. The LEDs on the phone are even repurposed to blink happily depending on what is going on, which is a nice touch.

Of course, it doesn’t end there. [poprhythm] also makes use of the microphone in the phone’s handset. Since the phone is now a MIDI instrument with both a microphone and note inputs, it’s possible to use them together as the inputs to vocoder software, which he demonstrates by covering Around the World by Daft Punk (video).

We love how [poprhythm] explains how he interfaced to everything because hardware work is all about such details, and finding the right resources. Here’s the GitHub repository for the Arduino code and a few links to other resources.

We have seen MIDI phone projects before, and each one is always unique in its own way: here’s a different approach to converting a keypad phone to MIDI, and this rotary pulse-dial phone went in a completely different direction with the phone itself completely unmodified, using only external interfacing.

You can admire [poprhythm]’s Touch Tone MIDI Phone in action in the short videos embedded below, with each one showing off a different aspect of the build. It’s great work!

Continue reading “Touch Tone MIDI Phone And Vocoder Covers Daft Punk” →

The Ease Of Wireless Charging, Without The Wait

September 2, 2022 by 14 Comments

Historically, there have been a few cases of useful wireless power transmission over great distances, like a team at MIT that was able to light up a 60 W bulb at several meters, and of course Nikola Tesla had grand dreams of drawing energy from the atmosphere. But for most of us wireless power is limited to small, short-range devices like cellphone chargers. While it’s not a lot of work to plug in a phone when it needs a charge, even this small task can be automated.

This build begins with a 3D printed cradle for the smartphone to sit in. When the device detects that the phone has been placed in the cradle, it uses a linear actuator to drive a custom-built charging cable into the phone’s USB port. Similarly, when the phone is lifted from the cradle the cable is automatically removed. It appears that there is some play in the phone’s position that lets the charger be plugged in smoothly, and the project’s creator [Larpushka] points out that the linear actuator is not particularly strong so we don’t imagine the risk of damage is very high.

While wireless charging still may have the edge when it comes to keeping debris out of the port, we still really enjoy a project like this that seems to be done for its own sake. There are some improvements that [Larpushka] plans to make, but for now we’re delighted by this build. For anyone looking to add true wireless charging to any phone that doesn’t have it, though, it’s not too difficult to accomplish either.