This Tiny TFT Pendant Is Digital Jewelry

Hackers have a multitude of skills, many are well-versed in the ways of all things that blink and flash. These abilities have often be applied to the field of jewelry and human adornment, and many LEDs have been employed in this work. [Deshipu] has been attempting something a touch different however, by constructing a tiny TFT pendant.

The basic idea is not dissimilar from those USB photo keychains of recent history. A SAMD21 Cortex M0+ serves as the brains of the operation, with the tiny microcontroller being soldered to a custom PCB that makes up the body of the pendant. A ST7735S TFT LCD screen is then attached to act as the display. Charging and delivery of images is done over USB, which can be handled natively by the SAMD21.

Currently, the pendant is capable of displaying 16-color BMPs, with the intention to create a converter for animated GIFs in the pipeline. Potential upgrades also involve creating a larger battery pack to sit behind the wearer’s neck, as currently the device has just 8 mAh to work with.

It’s a nicely designed piece, with the pendant appearing barely bigger than the screen itself. It’s not the first time we’ve seen a hacker take on a pendant, and we’re sure it won’t be the last. If you’ve got the goods, be sure to hit up the tip line. 

Everything You Probably Didn’t Know About FOV In HMDs

VR headsets have been seeing new life for a few years now, and when it comes to head-mounted displays, the field of view (FOV) is one of the specs everyone’s keen to discover. Valve Software have published a highly technical yet accessibly-presented document that explains why Field of View (FOV) is a complex thing when it pertains to head-mounted displays. FOV is relatively simple when it comes to things such as cameras, but it gets much more complicated and hard to define or measure easily when it comes to using lenses to put images right up next to eyeballs.

Simulation of how FOV can be affected by eye relief [Source: Valve Software]
The document goes into some useful detail about head-mounted displays in general, the design trade-offs, and naturally talks about the brand-new Valve Index VR headset in particular. The Index uses proprietary lenses combined with a slight outward cant to each eye’s display, and they explain precisely what benefits are gained from each design point. Eye relief (distance from eye to lens), lens shape and mounting (limiting how close the eye can physically get), and adjustability (because faces and eyes come in different configurations) all have a role to play. It’s a situation where every millimeter matters.

If there’s one main point Valve is trying to make with this document, it’s summed up as “it’s really hard to use a single number to effectively describe the field of view of an HMD.” They plan to publish additional information on the topics of modding as well as optics, so keep an eye out on their Valve Index Deep Dive publication list.

Valve’s VR efforts remain interesting from a hacking perspective, and as an organization they seem mindful of keen interest in being able to modify and extend their products. The Vive Tracker was self-contained and had an accessible hardware pinout for the express purpose of making hacking easier.  We also took a look at Valve’s AR and VR prototypes, which give some insight into how and why they chose the directions they did.

Salvaging Audio Amplifiers From Vintage Volvos

The common automotive scrap yard is a land of plenty for the enterprising hacker., where many items that would be prohibitively expensive elsewhere can often be had for a song. This isn’t just limited to strictly automotive parts either, as the modern vehicle is full of all kinds of hardware. [Nikita] managed to salvage a pair of audio amplifiers from an old Volvo, and put them to good use. It’s a great idea if you’re looking for cheap audio hardware!

The amplifiers are from a Volvo 760 made in 1984. There’s one rated at 40 watts per channel, and a smaller device rated at 25 watts per channel – likely to drive the front and rear speakers from separate amps. The amplifiers take 12 volts nominally, as one would expect. After some initial testing with a car battery and unsticking old relays, things began to crackle into life.

With the hardware now functioning, it was simply a case of bolting the amplifiers into a frame, hooking them up to a converted ATX power supply, and wiring up some connectors for speakers and audio input. With a few bits and pieces invested, [Nikita] now has a good quality amplifier to run audio in the workshop.

There’s plenty of useful hardware you can score down at the wreckers, and we see these parts used in hacks all the time – from peculiar milling machines to automated watering systems.

New Part Day: This $10 Rocking Single Board Computer Does Everything You Want

Single board computers are great, but what we really need are cheap single board computers. Running Linux on anything isn’t as good as running Linux on everything, and all that. To that end, here is the Rock Pi S, a $10 single board computer with Ethernet, WiFi, and it costs $10.

This one comes from the boffins at Radxa, already behind the footnote-worthy Rock Pi 4, a single board computer that appears to be heavily derived from the Raspberry Pi but with a 4 in the name so it’s obviously better. It also has 4 GeeBees of RAM, so it’s got that going for it too. Their latest product is the Rock Pi S, a board that seems as though it’s taking inspiration from the C.H.I.P.. The biggest selling point is of course the price: $10 for the version with 256MB of RAM and without WiFi or Bluetooth. Various other incarnations exist with permutations of 256MB or 512MB of RAM, and with or without WiFi and Bluetooth. The highest spec variant costs $16, but is sold out at the moment.

This tiny little single board computer fills a need in the marketplace; the Raspberry Pi Zero is cheap and small when it’s available, but sometimes you need Ethernet for various reasons and a real USB A port is great to have. We’re looking forward to the builds this tiny board enables and all the fantastic creations that will come from a community so very interested in single board computers.

Bunnie Huang Talks Manufacturing And Component Choices During Hackaday Prize Mentoring Session

Andrew “Bunnie” Huang’s mentor session for the Hackaday Prize shows off the kind of experience and knowledge hard to come by unless you have been through the hardware development gauntlet countless times. These master-classes match up experts in product development with Prize entrants working to turn their projects into products. We’ve been recording them so that all may benefit from the advice and guidance shared in each session.

The appealing little FunKey pocket gaming platform.
The appealing little FunKey pocket gaming platform.

Bunnie is someone who is already familiar to most Hackaday readers. His notoriety in our community began nearly two decades ago with his work reverse engineering the original Microsoft X-box, and he quickly went on to design (and hack) the Chumby Internet appliance, he created the Novena open-source laptop, and through his writing and teaching, he provides insight into sourcing electronic manufacture in Shenzhen. He’s the mentor you want to have in your corner for a Hackaday Prize entry, and that’s just what a lucky group had in the video we’ve placed below the break.

While this session with Bunnie is in the bag it’s worth reminding you all that we are still running mentor sessions for Hackaday Prize entrants, so sign up your entry for a chance to get some great feedback about your project.

The first team to meet with Bunnie are FunKey, whose keychain Nintendo-like handheld gaming platform was inspired by a Sprite_tm project featuring a converted novelty toy. The FunKey team have produced a really well-thought-out design that is ready to be a product, but like so many of us who have reached that point they face the impossible hurdle of turning it into a product. Their session focuses on advice for finding a manufacturing partner and scaling up to production.

A prototype HotorNot Coffee Stirrer, showing their problem of having to maintain food-safe components.
A prototype HotorNot Coffee Stirrer, showing their problem of having to maintain food-safe components.

HotorNot Coffee Stirrer is trying to overcome a problem unique to their food-related project. A hot drink sensor that has to go in the drink itself needs to be food safe, as well as easy enough to clean between uses. A variety of components are discussed including a thermopile on a chip that has the advantage of not requiring contact with the liquid, but sometimes the simplest ideas can be the most effective as Bunnie reminds us that a cheap medical thermometer teardown can tell us a lot about appropriate parts for this application.

The idea behing PhalangePad is an attractive one, but making those sensors reliable is no trivial eercise.
The idea behing PhalangePad is an attractive one, but making those sensors reliable is no trivial eercise.

It’s another component choice problem that vexes PhalangePad, an input device that relies on the user tapping the inside of their fingers with their thumb. It’s a great idea, but how should these “keypresses” be detected? Would you use a capacitive or magnetic sensor, a force sensitive resistors, or maybe even machine vision? Here Bunnie’s encyclopaedic knowledge of component supply comes to the fore, and the result is a fascinating insight into the available technologies.

We all amass a huge repository of knowledge as we pass through life, some of the most valuable of which is difficult to pass on in a structured form and instead comes out as incidental insights. An engineer with exceptional experience such as Bunnie can write the book on manufacturing electronics in China but still those mere pages can only scratch the surface of what he knows about the subject. There lies the value of these mentor sessions, because among them the gems of knowledge slip out almost accidentally, and if you’re not watching, you’ll miss them.

This is the second in our series of Hackaday Prize mentoring sessions this year, but we have more already in the can and further sessions to record. We’re constantly looking for more participants though, so make sure if you haven’t already that you put your entry in for Hackaday Prize and check out the list of mentors who are here to share their knowledge and experience. Continue reading “Bunnie Huang Talks Manufacturing And Component Choices During Hackaday Prize Mentoring Session”

Retrotechtacular: This Boat Isn’t Sinking… It’s Doing Research

It looks like a ship when it is in port or in transit, and when it use you’d think it’s about to sink. The RP FLIP (for “FLoating Instrument Platform)  is an unpowered research buoy with a very special design designed to provide the most stable and vibration-free platform possible for scientists studying the properties of the sea.

RP FLIP interrior bathroom design has two sinks mounted at 90 degree angles.

Scientific research often places demanding requirements upon existing infrastructure, requiring its own large projects tailored to their individual task. From these unusual needs sometimes come the most curious buildings and machinery. RP FLIP is designed to provide the most stable and vibration-free platform possible for scientists studying the properties of the sea. By flooding tanks in its bow it transfers from horizontal and floating on the surface to vertical and half-submerged when it is deployed. With its stern protruding from the water and pointing skywards it has the appearance of a sinking ship. What’s really neat is that its interior is cleverly designed such that its crew can operate it in either horizontal or vertical positions.

The original impetus for FLIP’s building was the US Navy’s requirement to understand the properties of sound waves in the ocean with relation to their submarines and presumably also those of their Soviet adversaries. Research submarines of the 1950s were not stable enough for reliable measurements, and the FLIP, launched in 1962, was built to address this by providing a far more stable method of placing a hydrophone at depth. Since then it has participated in a significant number of other oceanographic studies as diverse as studying the propagation of waves across the Pacific, and the depth to which whales dive.

The videos below should give a good introduction to the craft. The first one is a glossy promotional video from its operator, the Scripps Institution Of Oceanography, on its 50th anniversary, while the lower of the two is a walkaround by a scientist stationed aboard. In this we see some of the features for operating in either orientation, such as a toilet facilities mounted at 90 degrees to each other.

It appears that FLIP is in good order and with continuing demand for its services that should see it still operating well into the future. Those of us who live near Atlantic waters may never see it in person but it remains one of the most unusual and technically intriguing vessels afloat.

FLIP is not the only 1960s oceanographic research buoy we’ve covered, should you have an interest in such things.

Continue reading “Retrotechtacular: This Boat Isn’t Sinking… It’s Doing Research”

Hackaday Podcast Ep24: Mashing Smartphone Buttons, Sound Blastering, Trash Printing, And A Ludicrous Loom

Hackaday Editors Elliot Williams and Mike Szczys wade through the fun hacks of the week. Looks like Google got caught ripping off song lyrics (how they got caught is the hack) and electric cars are getting artificially noisier. We look at 3D Printing directly from used plastic, and building a loom with many hundreds of 3D printed parts. The Sound Blaster 1.0 lives again thanks to some (well-explained) reverse engineered circuitry. Your smartphone is about to get a lot more buttons that work without any extra electronics, and we’ll finish things up with brass etching and downloadable nuclear reactor plans.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Direct download (59 MB)

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Continue reading “Hackaday Podcast Ep24: Mashing Smartphone Buttons, Sound Blastering, Trash Printing, And A Ludicrous Loom”