Hardware Hack Makes Robocall Blocking Service Even Better

Sorry to bear sad tidings, but your car’s extended warranty is about to expire. At least that’s what you’ll likely hear if you answer one of those robocalls that have descended like a plague upon us. We applaud any effort to control the flood of robocalls, even if it means supplementing a commercial blocking service with a DIY ring-blocker.

The commercial service that [Jim] engaged to do his landline blocking is called Nomorobo – get it? It uses the Simultaneous Ringing feature many VoIP carriers support to intercept blacklisted robocallers, but with a catch: it needs caller ID data, so it lets the first ring go through. [Jim]’s box intercepts the ringing signal coming from his Xfinity modem using a full-wave rectifier and an analog input on an Arduino. Once the ring pattern is received, the Arduino flips a relay that connects all the phones in the house to the line, letting the call ring through. If Nomorobo has blocked the call, he’ll never hear a thing. There were a few glitches to deal with, like false positives from going off- and on-hook, but those were handled in software. There’s also a delay in displaying caller ID information on his phones, but it’s a small price to pay for peace.

Any escalation in the war on robocalls is justified, and we applaud [Jim] for his service. Should you feel like joining the fray, step one is to know your enemy. This primer on robocalling will help.

Thanks to [Phil] for the tip.

Flip Phones Are Making A Comeback

If you’re the kind of person who hates this new generation of smartphone users and longs for a nostalgic past, you’re not far from the new target demographic for many commercial phone manufacturers. Major phone companies like Motorola and Huawei have been developing foldable versions of conventional smartphone designs, intended to be more versatile while maintaining the same functionality as their less flexible counterparts.

It’s certainly gimmicky, but phones like the Samsung Galaxy Fold, the Motorola Razr, and the Huawei MateX are elegant from an engineering perspective. Developing a seamless interface experience, maximizing surface area for functionality, and maintaining the same nostalgic flip phone aesthetic while making use of familiar smartphone features isn’t an easy design process.

Motorola RAZR hinge shown by CNET’s Patrick Holland during a tour of their labs.

For the Razr, a hinge system that takes up about a third of the phone’s internal space allows the OLED display to have no noticeable binder line. Rather than curving like a piece of paper, it forms a teardrop shape that prevents the screen from creasing and being damaged. Springs and pistons below the surface move small places underneath where the user will be tapping – folded in, the plates slide away. It’s an interesting effect, although as you can see in the banner image, it doesn’t quite achieve optically flat perfection.

In order to ensure that the screen doesn’t overheat as it bends, it is made up of microlayers sandwiched together. To balance weight, the circuits and battery is split into two, operating on each half of the device, an unusual design choice for smartphones. Placement of the array of radios and antennas is also a challenge since they can’t be too close to each other or the processor, which can interfere with signal transmission.

Other devices like the Royale Flexpai are more so proof-of-concepts making use of flexible screens and batteries, rather than capturing the aesthetics of a flip phone generation — but who doesn’t want their smartphone to unfold into a tablet when needed? The future of smartphone technology is looking interesting, and we’ll be sure to see even more iterations of flexible displays in the near future.

36C3: Phyphox – Using Smartphone Sensors For Physics Experiments

It’s no secret that the average smart phone today packs an abundance of gadgets fitting in your pocket, which could have easily filled a car trunk a few decades ago. We like to think about video cameras, music playing equipment, and maybe even telephones here, but let’s not ignore the amount of measurement equipment we also carry around in form of tiny sensors nowadays. How to use those sensors for educational purposes to teach physics is presented in [Sebastian Staacks]’ talk at 36C3 about the phyphox mobile lab app.

While accessing a mobile device’s sensor data is usually quite straightforwardly done through some API calls, the phyphox app is not only a shortcut to nicely graph all the available sensor data on the screen, it also exports the data for additional visualization and processing later on. An accompanying experiment editor allows to define custom experiments from data capture to analysis that are stored in an XML-based file format and possible to share through QR codes.

Aside from demonstrating the app itself, if you ever wondered how sensors like the accelerometer, magnetometer, or barometric pressure sensor inside your phone actually work, and which one of them you can use to detect toilet flushing on an airplane and measure elevator velocity, and how to verify your HDD spins correctly, you will enjoy the talk. If you just want a good base for playing around with sensor data yourself, it’s all open source and available on GitHub for both Android and iOS.

Continue reading “36C3: Phyphox – Using Smartphone Sensors For Physics Experiments”

Rotary Dial Becomes USB Keyboard

[Max] had a rotary dial from an old telephone and — unsurprisingly — had nothing in particular to do with it. The simple answer? Use an Arduino Leonardo to turn it into a USB keyboard device.

Of course, the Leonardo can easily impersonate a USB keyboard, so that’s the easy part of the project. Interfacing to the dial requires an understanding of how the phone system works.

While today, TouchTone phones are most common, they were quite uncommon for many years. Early phones required you to have an operator connect your circuit to another person’s circuit. Unfortunately for the operators, the system was inherently unscalable and also cost prohibitive.

There were a variety of schemes tried and — supposedly — an undertaker who was angry that the operator was connecting his customers to her husband’s competing mortuary invented the dial telephone.

The details are pretty simple. A typical dial has two contacts. There’s a normally open contact that closes when you spin the dial to any position. It says closed until the spring returns the dial to the home position.

The other contact is normally closed and makes or breaks the phone line. Each time the dial rewinds past a position, the contact opens briefly. Of course, this is a mechanical system, so the software has to debounce the inputs, but that’s easy enough.

If you don’t have access to a dial, you could always print one. Sort of.

Finally Run Useful Apps On A Windows Phone

Not every piece of technology or software can succeed, even with virtually unlimited funding and marketing. About the same number of people are still playing Virtual Boys as are using Google Plus, for example. In recent memory, the Windows Phone occupies the same space as these infamous failures, potentially because it was late to the smartphone game but primarily because no one wanted to develop software for it. But now, you can run Android apps on Windows Phones now. (Google Translate from German)

To be clear, this doesn’t support all Android apps or all Windows Phones, and it will take a little bit of work to get it set up at all. But if you still have one laying around you might want to go grab it. First you’ll need to unlock the phone, and then begin sending a long string of commands to the device which sends the required software to the device. If that works, you can begin loading Android apps on the phone via a USB connection to a PC.

This hack came to us via Windows Central and Reddit. It seems long and involved but if you have any experience with a command line you should be fine. It’s an interesting way to get some more use out of your old Windows Phone if it’s just gathering dust in a closet somewhere. If not, don’t worry; Windows Phones were rare even when they were at their most popular. We could only find one project in our archives that uses one, and that was from 2013.

Cramming Dual SIMs & A Micro SD Card Into Your Phone

There are plenty of dual SIM phones on the market these days, but most of them are a hamstrung by packaging issues. Despite their dual SIM capability, this usually comes at the expense of the microSD card slot. Of course, hackers don’t accept such nonsense, and [Tweepy] went about crafting a solution. Sadly the make and model of phone aren’t clear.

It’s a simple case of very carefully shaving both the microSD card and the nano-SIM down until both can fit in the card tray. The SIM is slimmed down with the application of a heat gun helping to remove its plastic backing, saving precious fractions of a millimeter. The SD card is then filed down to make just enough space for the SIM to fit in underneath. Thanks to the springiness of the contacts in the phone, it’s just barely possible to squeeze both in, along with some Kapton tape to hold everything in place.

Your mileage may vary, depending on the construction of your SD card. Overall though, it’s a tidy hack that should prove useful to anyone with a dual SIM phone and limited storage. We saw a similar hack a few years ago, too.

[Thanks to Timothy for the tip!]

Control Your Web Browser Like It’s 1969

Imagine for a moment that you’ve been tasked with developing a device for interfacing with a global network of interconnected devices. Would you purposely design a spring-loaded dial that can do nothing but switch a single set of contacts on and off from 1 to 10 times? What kind of crazy world would we have to live in where something like that was the pinnacle of technology?

Obviously, such a world once existed, and now that we’ve rolled the calendar ahead a half-century or so, both our networks and our interfaces have gotten more complex, if arguably better. But [Jan Derogee] thinks a step backward is on order, and so he built this rotary phone web browser. The idea is simple: pick up the handset and dial the IP address of the server you want to connect to. DNS? Bah, who needs it?

Of course there is the teensy issue that most websites can’t be directly accessed via IP address anymore, but fear not – [Jan] has an incredibly obfuscated solution to that. It relies on the fact that many numbers sound like common phrases when sounded out in Chinese, so there end up being a lot of websites that have number-based URLs. He provides an example using the number 517, which sounds a bit like “I want to eat,” to access the Chinese website of McDonald’s. How the number seven sounding like both “eat” and “wife” is resolved is left as an exercise to the reader.

And here we thought [Jan]’s rotary number pad was of questionable value. Still, we appreciate this build, and putting old phones back into service in any capacity is always appreciated.

Continue reading “Control Your Web Browser Like It’s 1969”