Make “Wireless” Earbuds Truly Wireless

[Don] bought some off-brand Bluetooth earbuds online that actually sound pretty good. But while it’s true that they don’t require wires for listening to tunes, the little storage/charging box they sleep in definitely has a micro USB port around back. Ergo, they are not truly wireless. So [Don] took it upon himself to finish what the manufacturer started. Because it’s 2019, and words have meaning.

Finally, he had a use for that Qi charger he’s had lying around since the Galaxy S5 era. [Don] pried the earbud case open with a guitar pick and found a nicely laid-out charging circuit board without any black goop.

Once he located ground and Vcc pads, it was just a matter of performing a bit of surgery on the coil’s pins so he could solder wires there instead. Miraculously, the Qi coil fit perfectly inside the bottom of the case and the plastic is thin enough that it doesn’t interfere with the charging.

Want to try it for yourself? [Don]’s done an excellent job of documenting this hack, with clear pictures of every step. Soon you’ll be able to rid yourself of all those pesky USB cables.

Of course, [Don] still has to plug the charging base into the wall. If he ever wanted to add another level of wireless, he could always retrofit the base coil into his laptop.

PVC Pipe Turned Portable Bluetooth Speaker

We’ve always felt that sections of PVC pipe from the home improvement store are a criminally underutilized construction material, and it looks like [Troy Proffitt] feels the same way. Rather than trying to entirely 3D print the enclosure for his recently completed portable Bluetooth speaker, he combined printed parts with a piece of four inch pipe from the Home Depot.

While using PVC pipe naturally means your final hardware will have a distinctly cylindrical look, it does provide compelling advantages over trying to print the entire thing. For one, printing an enclosure this large would have taken hours or potentially even days. But by limiting the printed parts to accessories like the face plate, handle, and caps, [Troy] reduced that time considerably. Of course, even if you’re not in a rush, it’s worth mentioning that a PVC pipe will be far stronger than anything your desktop FDM printer is likely to squirt out.

[Troy] provides links for all the hardware he used, such as the speakers, tweeters, and the Bluetooth audio board itself. The system is powered by an 1800 mAh 3S RC-style battery pack that he says lasts for hours, though he also links to a wall adapter that can be used if you don’t mind being tethered. Unfortunately it doesn’t look like he has any internal shots of the build, but given the relatively short parts list, we imagine it’s all fairly straightforward inside.

While this is certainly a respectable looking build considering it started life in the plumbing aisle, we have to admit that we’ve seen some portable Bluetooth speakers with fully 3D printed enclosures in the past that looked absolutely phenomenal. The tradeoff seems pretty clear: reuse existing materials to save time, print them if you don’t mind reinventing the wheel occasionally.

2D-Scanner Records Surfboard Profiles For Posterity

[Ryan Schenk] had a problem: he built the perfect surfboard. Normally that wouldn’t present a problem, but in this case, it did because [Ryan] had no idea how he carved the gentle curves on the bottom of the board. So he built this homebrew 2D-scanner to make the job of replicating his hand-carved board a bit easier.

Dubbed the Scanbot 69420 – interpretation of the number is left as an exercise for the reader, my dude – the scanner is pretty simple. It’s just an old mouse carrying a digital dial indicator from Harbor Freight. The mouse was gutted, with even the original ball replaced by an RC plane wheel. The optical encoder and buttons were hooked to an Arduino, as was the serial output of the dial indicator. The Arduino consolidates the data from both sensors and sends a stream of X- and Z-axis coordinates up the USB cable as the rig slides across the board on a straightedge. On the PC side, a Node.js program turns the raw data into a vector drawing that represents the profile of the board at that point. Curves are captured at various points along the length of the board, resulting in a series of curves that can be used to replicate the board.

Yes, this could have been done with a straightedge, a ruler, and a pencil and paper – or perhaps with a hacked set of calipers – but that wouldn’t be nearly as much fun. And we can certainly see applications for this far beyond the surfboard shop.

Professional Audio On An ESP32

Audiophiles have worked diligently to alert the rest of the world to products with superior sound quality, and to warn us away from expensive gimmicks that have middling features at best. Unfortunately, the downside of most high quality audio equipment is the sticker price. But with some soldering skills and a bit of hardware, you can build your own professional-level audio equipment around an ESP32 and impress almost any dedicated audiophile.

The list of features the tiny picoAUDIO board packs is impressive, starting with a 3.7 watt stereo amplifier and a second dedicated headphone amplifier. It also has all of the I/O you would expect something based on an ESP32 to have, such as I2S stereo DAC, an I2S microphone input, I2C GPIO extenders and, of course, a built-in MicroSD card reader. The audio quality is impressive too, and the project page has some MP3 files of audio recorded using this device that are worth listening to.

Whether you want the highest sound quality for your headphones while you listen to music, or you need a pocket-sized audio recording device, this might be the way to go. The project files are all available so you can build this from the ground up as well. Once you have that knocked out, you can move on to building your own speakers.

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Hackaday Links: October 6, 2019

“If you or someone you love has been exposed to questionable quality electrolytic capacitors, you could be entitled to financial compensation.” Perhaps that’s not exactly the pitch behind this class action lawsuit against capacitor manufacturers, but it might as well be. The suit claims that the defendants, a group of capacitor manufacturers that includes Nichicon, Matsuo, ELNA, and Panasonic, “engaged in an unlawful conspiracy to fix, raise, maintain, or stabilize the prices of Capacitors.” Translation: if you bought capacitors between 2002 and 2014 from a distributor, you paid too much for them. The suit aims to recover a bunch of money from the defendants and divide it up between all the class members, so make sure you go back through all your receipts from Mouser and DigiKey over the last 17 years so you can file a claim that could be worth several dozen cents.

When are people going to learn that posting pictures of their illegal activities online is an Official Bad Idea? One SpaceX fan earned a night in jail after posting selfies he took with Starhopper, the SpaceX test article currently residing at Elon Musk’s would-be spaceport at Boca Chica, Texas. JB Wagoner, a SpaceX super-fan, made the pilgrimage from California to Texas — in his Tesla of course — to see the recent Starship Mark 1 unveiling, and decided to take a side trip to see the Starhopper. He parked at a beach, climbed a dune, and was able to walk right up to Starhopper and go selfie-crazy. After posting the pictures on Facebook, he was arrested, interviewed by Homeland Security, charged with criminal trespass, and thrown in a cell overnight. Wagoner has since been bonded out, but the charges might not stick, since Texas trespassing law requires clear signage or verbal notification of trespass, neither of which Wagoner encountered. SpaceX had even let the fence between the beach and the Starhopper collapse, so Wagoner seems to have had no way of knowing he was trespassing. Still, posting the pictures online was probably asking for trouble.

As satire and dark comedy, the 1987 cyberpunk classic RoboCop can’t be beat. But it also managed to accurately foreshadow a lot of what was to come in the world in terms of technology. No, we don’t have cyborg law enforcement — yet — but we do have something predicted by one throwaway scene: robotic realtors. In the movie, kiosks were set up around Murphy’s old house to extol the various virtues of living there, which ended up triggering the cyborg and starting the film’s climactic rampage. The real-life robotic realtor is a little more flexible, more like a telepresence robot — described aptly as “a Segway with an iPad on top.” The robotic realtor is not autonomous; it only lets a remote realtor interact with potential homebuyers without having to travel to multiple homes. It seems a little gimmicky to us, but the robots are reported to have made 25 sales in their first year on the job.

We’ve been seeing a lot of cheap resin printers these days, enough to make us want to jump into the market and start playing with them. But the cheap ones are all cheap for the same reason — they’re so dang small! They all use LCD screens from phones to mask off the UV light used to cure the resin, and the resulting print volume is tiny. Clem Mayer from MayerMakes has bigger ideas, though: he wants to make a giant resin printer using an LCD monitor as the mask. It’s not as simple as using a bigger screen, though; the film used between the screen and the resin, a fluoropolymer film called FEP, gets deformed when used on larger screens. So Clem is looking at a new built-plate interface that floats the resin on a layer of denser, immiscible liquid. It’s an interesting idea that is still clearly in the proof-of-concept phase, but we look forward to seeing what progress Clem makes.

Soldering Your Own Soldering Iron

A device that even DIY enthusiasts don’t usually think to DIY is the humble soldering iron. Yet, that’s exactly what one Hackaday.io user did by building a USB-powered soldering pen with better performance than a $5 Chinese soldering pen.

The project draws inspiration from another Weller RT tip-based soldering pen by [vlk], although this project has a simpler display than an OLED. Slovakia-based maker [bobricius] was inspired by the DiXi ATSAMD11C14-based development board. The project uses the same 32-bit ATMEL ARM microcontroller with a USB bootloader, which makes updating the firmware a lot easier.

Two buttons control the heat (+/-) and the jack for the Weller RT soldering tip controls the power out with PWM. For the display, 20 Charlieplexed 3014 LEDs are used to show the temperature from 0-399. The last missing LED is left out since 5 GPIO pins can only drive 20 LEDs.

Assuming that the main heating controls stay the same as [vlk]’s project, the pen uses a current sensor and heating controller for PID control of a heating module, which connects to the SMT connector for the Weller RT soldering iron tip. The temperature sensor uses a an op-amp for amplification of the signal from a type K thermocouple.

While there aren’t currently GERBER files for the PCB yet, the project is based on the open-source OLED display soldering pen project by [vlk], whose schematic for the device is published.

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A Modular Ecosystem That Evolved Around A Simple Diesel Engine

High volume commodity products are a foundation of hacking, we’ve built many projects around popular form factors like NEMA 17 stepper motors, 608 bearings, and 280 DC motors. Their high volume led to lower cost, which further increased popularity, and the cycle repeats. A similar thing happened to a style of single-cylinder diesel engine in China, and [Jalopnik] takes us through an exploration of these “Tuo La Ji” (tractor) machines.

Like many popular standards, circumstances elevated this style of engine to become more popular than its peers. Judging from the pictures, the idea is similar to NEMA 17 in that the core essence is a bolt pattern and an output shaft. Different manufacturers offer various capabilities within this space, and a wild assortment of machinery evolved to take advantage of this class of power source.

It starts with a set of wheels and handlebars to create a walk-behind farm tractor, something pretty common around the world. But this particular ecosystem grew far beyond that to many other applications, including full sized trucks with off-road capability that would embarrass most of the genteel SUVs cruising our roads today. They may not be fast, but they only needed to be faster and have longer endurance than beasts of burden to be effective as “a horseless horse”.

Due to factors such as poor crash safety, absence of diesel emission controls, and affordability of more powerful (and faster!) vehicles, these machines are a dying breed. But that won’t change the fact there was a fantastic amount of mechanical hacking ingenuity that had sprung up around this versatile engine building simple and effective machines. Their creativity drew from the same well that fed into these Indonesian Vespas.

Photo by [Brian Holsclaw] CC BY-ND 2.0