Open-Source Cell Phone Based On ESP32

Over the past decade or so, smartphones have exploded in popularity and seamlessly integrated themselves into nearly every aspect of most people’s lives. Although that comes with a few downsides as well, with plenty of people feeling that the smart phone makes it a little too easy to waste time and looking to switch to something simpler, like an older-style flip phone. If this style of phone is more your speed, take a look at this DIY cell phone which takes care of everything a phone really needs to do. (Google Translate from French)

The phone uses an ESP32 at its core, with a SIM800L GSM modem to interact with the cell network, including retrieving the system time. A small battery is included as well as all of the support circuitry for charging it as well as a USB interface that can communicate to a PC. The operating system for the phone is built from the ground up as well, with a touch screen interface allowing the user to make phone calls, send text messages, store contacts, and a few other basic features. There’s also a GPS application though, allowing the phone to know basic location information.

Another perk of this device is that its creator, [Gabriel], made the design schematics, print files for the case, and the operating system software completely open source for anyone to build this phone on their own. Everything is available on the project’s GitHub page. It’s a fairly remarkable achievement, especially considering [Gabriel] is only 16. And, if you’re not one to eschew modern smart phone technology there are some DIY smart phones available to build as well.

Thanks to [come2] for the tip!

Bringing Back The Minitel

If you didn’t live in France in the 80s or 90s, it’s likely you missed out on one of the most successful computer networks in existence prior to the modern Internet. Known as Minitel, it was an online service available over existing phone lines that offered a connected computer terminal for users to do most things we associate with the modern world, such as booking travel, viewing news, looking up phone numbers, and plenty of other useful activities. While a lot of the original system was never archived, there are still some efforts to restore some of its original functionality like this MiniMit.

The build requires either an original or a recreation of a Minitel terminal in all its 80s glory, but pairs an ESP32 to support modern network connectivity. The ESP32 interfaces with the Minitel’s DIN socket and provides it with a translation layer between WiFi and the networking type that it would have originally expected to see from the telephone lines. Two of the original developers of Minitel are working on restoring some of the services that would have been available originally as well, which means that the entire system is being redeveloped and not just the original hardware.

We’ve mentioned that this system was first implemented in the 80s, but the surprising thing is that even well after broadband Internet would have been available to most people in France, the Minitel system still had widespread use, not being fully deactivated until 2012. They remain popular as inspiration for other projects as well, like this one which was brought a little more up-to-date with the help of a modern display and Raspberry Pi.

A Mobile Phone From 1985

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

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

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

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

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.