House Training A Military TA-1024A Field Telephone

April 24, 2019 by Tom Nardi 11 Comments

After spotting some interesting military phones at a museum, [CuriousMarc] wondered what it would take to retrofit these heavy duty pieces of telecom equipment for civilian use. He knew most of the internals would be a lost cause, but reasoned that if he could reverse engineer key elements such as the handset and keypad, he might be able to connect them to the electronics of a standard telephone. Luckily for us, he was kind enough to document the process.

There were a number of interesting problems that needed to be solved, but the first and perhaps largest of them was the unusual wiring of the keypad. It wasn’t connected in the way modern hackers like us might expect, and [CuriousMarc] had to end up doing some pretty significant rewiring. By cutting the existing traces on the PCB with a Dremel and drilling new holes to run his wires around the back, he was able to convert it over to a wiring scheme that contemporary touch tone phones could use.

An adapter needed to be fabricated to mount a basic electret microphone in place of the original dynamic one, but the original speaker was usable. He wanted to adapt the magnetic sensor that detected when the handset was off the hook, but in the end it was much easier to just drill a small hole and use a standard push button.

The main board of the phone is a perfect example of the gorgeous spare-no-expense construction you’d expect from a military communications device, but unfortunately it had to go in the bin. In its place is the guts of a lowly RCA phone that was purchased for the princely sum of $9.99. [CuriousMarc] won’t be able to contact NORAD anymore, but at least he’ll be able to order a pizza. The red buttons on the keypad, originally used to set the priority level of the call on the military’s AUTOVON telephone network, have now been wired to more mundane features of the phone such as redial.

While this is fine for a one-off project, we’d love to see a drop-in POTS or VoIP conversion for these phones that didn’t involve so much modification and rewiring. Now that we have some documentation for things like the keypad and hook sensor, it shouldn’t be hard to take their idiosyncrasies into account with a custom PCB. Dragging vintage gear into the modern era is always a favorite pastime for hackers, so maybe somebody out there will be inspired to take on the challenge.

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Telephone Plays The Songs Of Its People

April 12, 2019 by Sven Gregori 4 Comments

Music, food, and coding style have one thing in common: we all have our own preferences. On the other hand, there are arguably more people on this planet than there are varieties in any one of those categories, so we rarely fail to find like-minded folks sharing at least some of our taste. Well, in case your idea of a good time is calling a service hotline for some exquisite tunes, [Fuzzy Wobble] and his hold music jukebox, appropriately built into a telephone, is just your guy.

Built around an Arduino with an Adafruit Music Maker shield, [Fuzzy Wobble] uses the telephone’s keypad as input for selecting one of the predefined songs to play, and replaced the phone’s bell with a little speaker to turn it into a jukebox. For a more genuine experience, the audio is of course also routed to the handset, although the true hold music connoisseur might feel disappointed about the wide frequency range and lack of distortion the MP3s used in his example provide. Jokes aside, projects like these are a great reminder that often times, the journey really is the reward, and the end result doesn’t necessarily have to make sense for anyone to enjoy what you’re doing.

As these old-fashioned phones gradually disappear from our lives, and even the whole concept of landline telephony is virtually extinct in some parts of the world already, we can expect to see more and more new purposes for them. Case in point, this scavenger hunt puzzle solving device, or the rotary phone turned virtual assistant.

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WiFi Controlled Plane Is Cheap Flying Fun

April 12, 2019 by Lewin Day 17 Comments

The world of radio controlled aircraft used to be an expensive and exclusive hobby, limited to those with the time and money to invest in difficult builds and pricey radio gear. More recently, the hobby has become more accessible, with cheap ready to fly planes available that can be flown in smaller spaces like suburban parks. [Ravi Butani] has built just such a plane, and you can even fly it with your smartphone!

An ESP8266 does double duty here as both the brains and the communication system. A custom smartphone app communicates with the plane over WiFi. Touching the screen increases the throttle, while steering is achieved through tilting the phone. There’s also monitoring of signal strength and battery level, with the phone vibrating if the plane is getting out of range or low on battery.

Flight control is via differential thrust, with power coming courtesy of two small DC motors controlled by tiny SMD MOSFETs. The plane flies remarkably well in still conditions, and the WiFi connection is stable in an open park environment. [Ravi] reports that control is possible at a range of around 70 meters using a Motorola G5S smartphone.

Despite the simplicity of the build and the low cost of the components, the final product performs admirably. It would be a great weekend project, and at the end of it, you get to go and fly your new plane! If you’re worried about keeping your batteries charged, don’t worry – there’s a solution for that. Video after the break.

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Reverse Engineering A Telephonic Relay Device

March 23, 2019 by Lewin Day 20 Comments

The Plain Old Telephone Service, or POTS, doesn’t get a lot of love from the average person anymore. Perhaps once in a while a payphone will be of use when a phone battery has died, but by and large many people simply don’t have hardwired phones anymore. However, that doesn’t mean that the old landline can’t be put to good use. As [Felix Vollmer] shows us, it’s still possible to get useful hardware running over the phone line.

The YC-KZ02DN is a simple device which hooks up to a standard phone line. It’s capable of answering calls and responding to commands by switching its various relays on or off. [Felix] wasn’t quite happy with the stock functionality, however. Investigation showed the onboard STC15W202S microcontroller can be repogrammed over serial via an unpopulated header. Thus opened the door to hacking the device.

[Felix]’s alternative firmware has a couple of key features that make it valuable. Longer PINs are supported, decreasing the likelihood that malicious actors can gain access to the system. Additionally, the device is set to restore the last relay state after a power loss event. This makes the device far more useful for situations where it’s important to ensure consistent operation. It’s no use if an intermittent power loss stops your livestock’s water trough from filling, for example.

In this day and age of the Internet of Things, an old school telephony hack warms the cockles of our hearts. We’re suckers for anything that recalls the days of rotary dialing and speaking with the operator, after all.

Immersive Augmented Reality On A Budget

February 18, 2019 by Tom Nardi 6 Comments

By now we’ve all seen the cheap headsets that essentially stick a smartphone a few inches away from your face to function as a low-cost alternative to devices like Oculus Rift. Available for as little as a few dollars, it’s hard to beat these gadgets for experimenting with VR on a budget. But what about if you’re more interested in working with augmented reality, where rendered images are superimposed onto your real-world view rather than replacing it?

As it turns out, there are now cheap headsets to do that with your phone as well. [kvtoet] picked one of these gadgets up for $30 USD on AliExpress, and used it as a base for a more capable augmented reality experience than the headset alone is capable of. The project is in the early stages, but so far the combination of this simple headset and some hardware liberated from inexpensive Chinese smartphones looks to hold considerable promise for delivering a sub-$100 USD development platform for anyone looking to jump into this fascinating field.

On their own, these cheap augmented reality headsets simply show a reflection of your smartphone’s screen on the inside of the lenses. With specially designed applications, this effect can be used to give the wearer the impression that objects shown on the phone’s screen are actually in their field of vision. It’s a neat effect to be sure, but it doesn’t hold much in the way of practical applications. To turn this into a useful system, the phone needs to be able to see what the wearer is seeing.

To that end, [kvtoet] relocated a VKWorld S8 smartphone’s camera module onto the front of the headset. Beyond its relatively cost, this model of phone was selected because it featured a long camera ribbon cable. With the camera on the outside of the headset, an Android application was created which periodically flashes a bright LED and looks for reflections in the camera’s feed. These reflections are then used to locate objects and markers in the real world.

In the video after the break, [kvtoet] demonstrates how this technique is put to use. The phone is able to track a retroreflector laying on the couch quickly and accurately enough that it can be used to adjust the rendering of a virtual object in real time. As the headset is moved around, it gives the impression that the wearer is actually viewing a real object from different angles and distances. With such a simplistic system the effect isn’t perfect, but it’s exciting to think of the possibilities now that this sort of technology is falling into the tinkerer’s budget.

If you don’t want to go the DIY route, Leap Motion has been teasing an open source augmented reality headset which has us quite excited. We’re still waiting on the hardware, but that hasn’t stopped hackers from coming up with some fascinating AR applications in the meantime.

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TréPhonos Calls Up History In Houston

February 8, 2019 by Brian McEvoy 7 Comments

Houston’s historic third ward, aka “The Tre,” is ~~ripe~~ rife with history, and some of that history is digitally preserved and accessible through an art installation in the form of repurposed payphones. We love payphones for obvious reasons and seeing them alive and kicking warms our hearts. Packing them with local history checks even more boxes. Twenty-four people collaborated to rebuild the three phones which can be seen in the video after the break, including three visual artists, three ambassadors, and eighteen residents who put their efforts into making the phones relevant not only to the ward but specifically to the neighborhood. One phone plays sound clips from musicians who lived or still live in the ward, another phone has spoken word stories, and the third has field recordings from significant locations in The Tre.

Each phone is powered by a solar cell and a USB battery pack connected to a Teensy with an audio adapter board, and a 20 watt amplifier. Buttons 1-9 play back recorded messages exclusive to each phone, star will record a message, and zero will play back the user-recorded message. Apps for smart phones are easy for young folks to figure out but the payphones ensure that these time capsules can be appreciated by people of any age, regardless of how tech savvy they are and that is wise as well as attractive. The coin return lever and coin slot also have associated sound clips unlike regular payphones so the artists get extra credit.

Did we say that we love payphones? Yes, yes we did. The very first post on Hackday was for a redbox and that got the ball rolling.

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CNC Mill Repairs IPhone 7

January 20, 2019 by Lewin Day 39 Comments

Modern smartphones are highly integrated devices, bringing immense computing power into the palm of one’s hand. This portable computing power and connectivity has both changed society in innumerable ways, and also tends to lead to said powerful computers ending up dropped on the ground or into toilets. Repairs are often limited to screen replacement or exchanging broken modules, but it’s possible to go much further.

The phone is an iPhone 7, which a service center reported had issues with the CPU, and the only fix was a full mainboard replacement. [The Kardi Lab] weren’t fussed, however, and got to work. The mainboard is installed in a CNC fixture, and the A10 CPU is delicately milled away, layer by layer. A scalpel and hot air gun are then used for some further cleanup of the solder pads. Some conductivity testing to various pads is then carried out, for reasons that aren’t entirely clear.

At this point, a spare A10 CPU is sourced, and a stencil is used to apply solder paste or balls – it is not immediately obvious which. The new chip is then reflowed on to the mainboard, and the phone reassembled. The device is then powered on and shown to be functional.

It’s an impressive repair, and shows that modern electronics isn’t so impossible to fix – as long as you have the right tools to hand. The smart thing is, by using the CNC machine with a pre-baked program, it greatly reduces the labor required in the removal stage, making the repair much more cost-effective. The team are particularly helpful, linking to the tools used to pull off the repair in the video description. We’ve seen similar hacks, too – such as upgrading an iPhone’s memory. Video after the break.

[Thanks to Nikolai for the tip!]

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