Use Your Earbud’s Media Controls On Your Laptop With This Useful Dongle

November 9, 2019 by Gerrit Coetzee 3 Comments

[David] sends in his very nicely designed “Thumpware Media Controller” that lets your mobile phone headphones control the media playback on your PC.

We realize that some PCs have support for the extra pins on cellphone earbuds, but at least some of us have experienced the frustration (however small) of habitually reaching up to touch the media controls on our earbuds only to hear the forlorn click of an inactive-button. This solves that, assuming you’re still holding on to those 3.5mm headphones, at least.

The media controls are intercepted by a PIC16 and a small board splits and interprets the signals into a male 3.5mm and a USB port. What really impressed us is the professional-looking design and enclosure. A lot of care was taken to plan out the wiring, assembly, and strain relief. Overall it’s a pleasure to look at.

All the files are available, so with a bit of soldering, hacking, and careful sanding someone could put together a professional looking dongle for their own set-up.

Serial Connection Over Audio: Arduino Can Listen To UART

May 31, 2018 by Ben James 19 Comments

We’ve all been there: after assessing a problem and thinking about a solution, we immediately rush to pursue the first that comes to mind, only to later find that there was a vastly simpler alternative. Thankfully, developing an obscure solution, though sometimes frustrating at the time, does tend to make a good Hackaday post. This time it was [David Wehr] and AudioSerial: a simple way of outputting raw serial data over the audio port of an Android phone. Though [David] could have easily used USB OTG for this project, many microcontrollers don’t have the USB-to-TTL capabilities of his Arduino – so this wasn’t entirely in vain.

At first, it seemed like a simple task: any respectable phone’s DAC should have a sample rate of at least 44.1kHz. [David] used Oboe, a high performance C++ library for Android audio apps, to create the required waveform. The 8-bit data chunks he sent can only make up 256 unique messages, so he pre-generated them. However, the DAC tried to be clever and do some interpolation with the signal – great for audio, not so much for digital waveforms. You can see the warped signal in blue compared to what it should be in orange. To fix this, an op-amp comparator was used to clean up the signal, as well as boosting it to the required voltage.

Prefer your Arduino connections wireless? Check out this smartphone-controlled periodic table of elements, or this wireless robotic hand.

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Hackaday Prize Entry: Clunke Button Powers Accessibility

October 5, 2017 by Kristina Panos 11 Comments

An AT button is a device that helps people with all kinds of physical disabilities to interact with their world. There isn’t much to them, just a switch wired up to a 3.5mm mono plug or jack, but the switch is installed in a large button housing that’s easy to operate.

These buttons can be used with any appliance or toy that can be adapted for mono input. They’re a simple piece of technology that makes a world of difference, but for some reason, they cost around $65 each. Because of this, people make their own simple switches, but these aren’t usually sturdy or long-lasting. [Christopher] thinks they should cost way less than that and set out to make buttons for about $10 in materials. Aside from the printed files, all you really need to make a Clunke button is one Cherry MX in your favorite shade of blue, blue, or blue, and either a 3.5mm mono jack or plug, depending on preference.

[Christopher] and his team devised the Clunke Button in collaboration with the local United Cerebral Palsy chapter as part of their senior design project. When it came time to present the project, they wanted to find a way to be able to pass a Clunke button around the audience and have it do something when pressed. They made an interactive ticker by adding an ESP-01 and a battery. [Christopher] has since taken over the project and continues to improve the design as he progresses through the Prize finals. Code for the ticker is available on GitHub, and the button STL files are on Thingiverse.

Bringing Back The IPhone7 Headphone Jack

September 7, 2017 by Adam Fabio 96 Comments

Plenty of people bemoaned Apple’s choice to drop the 1/8″ headphone jack from the iPhone 7. [Scotty Allen] wasn’t happy about it either, but he decided to do something about it: he designed a custom flex circuit and brought the jack back. If you don’t recognize [Scotty], he’s the same guy who built an iPhone 6 from parts obtained in Shenzhen markets. Those same markets were now used to design, and prototype an entirely new circuit.

The iPhone 7 features a barometric vent, which sits exactly where the headphone jack lived in the iPhone 6. The vent helps the barometric pressure sensor obtain an accurate reading while keeping the phone water proof. [Scotty] wasn’t worried about waterproofing, as he was cutting a hole through the case. The vent was out, replaced with a carefully modified headphone jack.

The next step was convincing the phone to play analog signals. For this, [Scotty] used parts from Apple’s own headphone adapter. The hard part was making all of this work and keeping the lightning port available. The key was a digital switch chip. Here’s how the circuit works:

When no headphone is plugged in, data is routed from the iPhone’s main board to the lightning port. When headphones are plugged in, the data lines are switched to the headphone adapter. Unfortunately, this means the phone can’t play music and charge at the same time — that is something for version 2.0.

The real journey in this video is watching [Scotty] work to fit all these parts inside an iPhone case. The design moved from a breadboard through several iterations of prototype printed circuit boards. The final product is built using a flexible PCB – the amber-colored Kapton and copper sandwiches that can be found in every mobile device these days.

Making everything fit wasn’t easy. Two iPhone screens perished in the process. But ultimately, [Scotty] was successful. He’s open sourced his design so the world can build and improve on it.

Want to read more about the iPhone 7 and headphone jacks? Check out this point and counterpoint. we published on the topic.

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Death To The 3.5mm Audio Jack, Long Live Wireless

October 25, 2016 by Gerrit Coetzee 359 Comments

There’s been a lot of fuss over Apple’s move to ditch the traditional audio jack. As for me, I hope I never have to plug in another headphone cable. This may come off as gleeful dancing on the gravesite of my enemy before the hole has even been dug; it kind of is. The jack has always been a pain point in my devices. Maybe I’ve just been unlucky. Money was tight growing up. I would save up for a nice set of headphones or an mp3 player only to have the jack go out. It was a clear betrayal and ever since I’ve regarded them with suspicion. Is this the best we could do?

I can’t think of a single good reason not to immediately start dumping the headphone jack. Sure it’s one of the few global standards. Sure it’s simple, but I’m willing to take bets that very few people will miss the era of the 3.5mm audio jack once it’s over. It’s a global episode of the sunk cost fallacy.

In the usual way hindsight is 20/20, the 3.5mm audio jack can be looked at as a workaround, a stop over until we didn’t need it. It appears to be an historic kludge of hack upon hack until something better comes along. When was the last time it was common to hook an Ethernet cable into a laptop? Who would do this when we can get all the bandwidth we want reliably over a wireless connection. Plus, it’s not like most Ethernet cables even meet a spec well enough to meet the speeds they promise. How could anyone reasonably expect the infinitely more subjective and variable headphone and amplifier set to do better?

But rather than just idly trash it, I’d like to make a case against it and paint a possible painless and aurally better future.

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Smart Watch Hack Lets You Use Your 3.5mm Headphones With An IPhone 7

September 23, 2016 by James Hobson 54 Comments

As you may have heard, the iPhone 7 is ditching the 3.5 mm headphone jack in the name of progress and courage. Whatever your take on that, it leaves the end user out in the cold if — for instance — their preferred headphones still use the old format. Here to save you from an untimely upgrade is YouTuber [Kedar Nimbalkar], who has modified a Bluetooth Smartwatch to incorporate a 3.5 mm jack to allow continued use your current headphones.

After opening up the smartwatch [Nimbalkar] removes the speaker, solders in a 3.5 mm headphone jack and clips out an opening in the watch’s case that maintains the watch’s sleek exterior.

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A 3D Printed Camera (Including The Lens)

September 10, 2016 by Brian Benchoff 25 Comments

Barring the RepRap project, we usually see 3D printers make either replacement parts or small assemblies, not an entire finished product. [Amos] is the exception to this rule with his entirely 3D-printed camera. Everything in this camera is 3D printed, from the shutter to the lightproof box to the lens itself. It’s an amazing piece of engineering, and a testament to how far 3D printing has come in just a few short years.

35mm film is the most common film by far, and the only one that’s still easy to get and have developed at a reasonable price. This 3D-printed camera is based on that standard, making most of the guts extremely similar to the millions of film cameras that have been produced over the years. There’s a film cartridge, a few gears, a film takeup spool, and a lightproof box. So far, this really isn’t a challenge for any 3D printer.

The fun starts with the lens. We’ve seen 3D printers used for lens making before, starting with a 3D print used to create a silicone mold where a lens is cast in clear acrylic, 3D printed tools used to grind glass, and an experiment from FormLabs to 3D print a lens. All of these techniques require some surface finishing, and [Amos]’ lens is no different. He printed a lens on his Form 2 printer, and started polishing with 400 grit sandpaper. After working up to 12000 grit, the image was still a bit blurry, revealing microscopic grooves that wouldn’t polish out. This led him to build a tool to mechanically polish the lens. This tool was, of course, 3D printed. After polishing, the lens was ‘dip polished’ in a vat of uncured resin.

The shutter was the next challenge, and for this [Amos] couldn’t rely on the usual mechanisms found in film cameras. he did find a shutter mechanism from 1885 that didn’t take up a lot of depth, and after modeling the movement in Blender, designed a reasonable shutter system.

Building an entire camera in a 3D printer is a challenge, but how are the pictures? Not bad, actually. There’s a weird vignetting, and everything’s a little bit blurry. It’s hip, trendy, and lomo, and basically amazing that it works at all.