A Microcontroller Friendly AR Headset On The Cheap

September 2, 2021 by Tom Nardi 9 Comments

Generating the real-time images required for augmented reality (AR) goggles usually requires a fair amount of processing power, to the point that DIY efforts based around the Raspberry Pi often have trouble keeping up. But what if your AR aspirations don’t require fancy high-resolution graphics? If text and the occasional icon is enough to get the job done, then these lo-fi AR goggles from [bobricius] might be the ideal solution.

As with previous homebrew AR rigs we’ve seen, this one starts with an affordable headset designed to project the display of a smartphone onto a pair of curved optical combiners. But instead of tucking a phone into the headset, [bobricius] is using a custom PCB that holds a pair of ST7789 1.3 inch 240 x 240 IPS displays. Connected over SPI and supported by just about any microcontroller you’d care to use, tossing some textual data over your field of vision can be accomplished in just a few lines of code.

[bobricius] has actually put together a couple different versions of the PCB for this project. One uses his custom ATSAMD21E18-based “ArmaBrain” module that packs the MCU and an array of common components onto a 28 mm square board that can be easily dropped into other projects. If you’d rather roll your own solution, the second version of the board that simply holds the two displays in the appropriate position and routes the SPI lines to a convenient header should do nicely.

We’ve seen augmented reality displays using microcontrollers like the ESP32 before, but those were essentially just remote displays for a more powerful system. We like this simplified approach, as there are plenty of applications where just getting a few lines of text or some low-resolution images would be more than sufficient for the task at hand. Plus, the commercially-made headset this project is based on certainly looks better than some of the other donor goggles we’ve contemplated modifying in the past.

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Nokia LCD Goes Transparent For Hands-Free Reminders

August 29, 2021 by Tom Nardi 1 Comment

These days everyone’s excited about transparent OLED panels, but where’s the love for the classic Nokia 5110 LCD? As the prolific [Nick Bild] demonstrates in his latest creation, all you’ve got to do is peel the backing off the the late 90s era display, and you’ve got yourself a see-through cyberpunk screen for a couple bucks.

In this case, [Nick] has attached the modified display to a pair of frames, and used an Adafruit QT Py microcontroller to connect it to the ESP32 powered ESP-EYE development board and OV2640 camera module. This lets him detect QR codes within the wearer’s field of vision and run a TensorFlow Lite neural network right on the hardware. Power is provided by a 2000 mAh LiPo battery running through an Adafruit PowerBoost 500.

The project, intended to provide augmented reality reminders for medical professionals, uses the QR codes to look up patient and medication information. Right now the neural network is being used to detect when the wearer has washed their hands, but obviously the training model could be switched out for something different as needed. By combining these information sources, the wearable can do things like warn the physician if a patient is allergic to the medication they’re currently looking at.

Relevant information and warnings are displayed on the Nokia LCD, which has been placed far enough away from the eye that the user can actually read the text; an important design consideration that [Zach Freedman] demonstrated with his (intentionally) illegible wearable display a few weeks back. That does make the design a bit…ungainly, but at least you don’t have to worry about hand-cutting your optics

mRNA badge next to an image of the actual Moderna vaccine nanoparticle.

Celebrate MRNA Vaccine With This Badge That Blinks The Nucleotide Code

August 24, 2021 by Jim Heaney 20 Comments

To celebrate getting his second vaccine dose [Paul Klinger] combined two of our favorite things — blinking lights and wearable tech — to create an awesome mRNA vaccine badge.

The badge, which is designed to be worn like a pendant, will slowly blink through all 4,000 nucleotides of the Moderna vaccine over the course of 10 minutes. Watch the video after the break to see it in action. Don’t worry if you got the Pfizer vaccine, you can use the interface button on the back of the badge to change over to Pfizer’s mRNA sequence instead. There’s even a handy legend on the badge, identifying the lipids in case your microbiology skills are a bit rusty.

On the reverse side of the board, you will find a handful of current limiting resistors, a CR2032 battery holder, and the ATtiny1617 microcontroller that runs everything. To assist in converting the mRNA sequence into LED pulses, [Paul] wrote a Python script that will automatically import the nucleotide string from the standard .fasta file and store each nucleotide in just 2 bits, allowing the entire sequence to fit in the program memory of the microcontroller.

This isn’t [Paul’s] first RNA-related project; he originally developed the aforementioned Python script to compress the entirety of the COVID-19 sequence, containing over 30,000 nucleotides, into program memory for his Virus Blinky project, that we featured last year.

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Why You Can’t Make A Wearable Display With A Transparent OLED

August 19, 2021 by Danie Conradie 37 Comments

After seeing the cheap transparent OLED displays that have recently hit the market, you might have thought of using them as an affordable way to build your own wearable display. To save you the inevitable disappointment that would result from such a build, [Zack Freedman] took it upon himself to test out the idea, and show why transparent wearable displays are a harder than it looks.

He put together a headband with integrated microcontroller that holds the transparent OLED over the user’s eye, but unfortunately, anything shown on the display ends up being more or less invisible to the wearer. As [Zack] explains in the video after the break, the human eye is physically incapable of focusing on any object at such a short distance. Contrary to what many people might think, the hard part of wearable displays is not in the display itself, but rather the optics. For a wearable display to work, all the light beams from the display need to be focused into your eyeball by lenses and or reflectors, without distorting your view of everything beyond the lens. This requires, lightweight and distortion-free collimators and beam splitters, which are expensive and hard to make.

While these transparent OLEDs might not make practical heads-up displays, they are still a cool part for projects like a volumetric display. It’s certainly possible to build your own smart glasses or augmented reality glasses, you just need to focus on getting the optics right.

3D Printed Fabric Stiffens On Demand

August 15, 2021 by Al Williams 20 Comments

Researchers in Singapore and at CalTech have developed a 3D printed fabric with an interesting property: it is generally flexible but can stiffen on demand. You can see a video about the new fabric, below.

The material consists of nylon octahedrons interlocked. The cloth is enclosed in a plastic envelope and vacuum-packed. Once in a vacuum, the sheet becomes much stiffer and can hold many times its own weight.

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3D Printed Smart Glasses Put Linux In Your Face

August 14, 2021 by Tom Nardi 20 Comments

Unimpressed by DIY wearables powered by dinky microcontrollers, [Teemu Laurila] has been working on a 3D printed head-mounted computer that puts a full-fledged Linux desktop in your field of view. It might not be as slim and ergonomic as Google Glass, but it more than makes up for it in terms of raw potential.

Featuring an overclocked Raspberry Pi Zero W, a ST7789VW 240×240 IPS display running at 60 Hz, and a front-mounted camera, the wearable makes a great low-cost platform for augmented reality experiments. [Teemu] has already put together an impressive hand tracking demonstration that can pick out the position of all ten fingers in near real-time. The processing has to be done on his desktop computer as the Zero isn’t quite up to the task, but as you can see in the video below, the whole thing works pretty well.

Structurally, the head-mounted unit is made up of nine 3D printed parts that clip onto a standard pair of glasses. [Teemu] says the parts will probably need to be tweaked to fit your specific frames, but the design is modular enough that it shouldn’t take too much effort. He’s using 0.6 mm PETG plastic for the front reflector, and the main lens was pulled from a cheap pair of VR goggles and manually cut down into a rectangle.

The evolution of the build has been documented in several videos, and it’s interesting to see how far the hardware has progressed in a relatively short time. The original version made [Teemu] look like he was cosplaying as a Borg drone from Star Trek, but the latest build appears to be far more practical. We still wouldn’t try to wear it on an airplane, but it would hardly look out of place at a hacker con.

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A rectangle-shaped wristband wearable, worn on a wrist

A Digital White Cane For The Visually Impaired

August 12, 2021 by Chris Wilkinson 22 Comments

The white cane (and its many variants) is an everyday carry for many visually impaired people. This low-tech tool allows those afflicted by visual impairment to safely navigate the world around them, and has been ubiquitous in many parts of the world for decades. [Madaeon] has been hard at work going one step further in prototyping an open-source assistive wearable that could help in situations where a cane is not practical, or useful.

The T.O.F Wristband V2 alerts its wearer to nearby obstacles through vibrations, and is able to detect objects up to four meters away. As the wearer veers closer and closer to an obstacle, the vibration increases in frequency. A time-of-flight distance sensor is controlled by a Feather, and the whole system is powered by a small lithium-polymer battery. The prototype consists of just four components plus a 3D printed case and bracelet, which inevitably keeps down costs and complexity.

Version two of this project picks up where version one left off. In that project, [Madaeon] mentioned the possibility of squeezing this project down to the size of a ring. Perhaps with better battery technology, a ring-sized sensor might just be possible one day.

This isn’t the first wearable that has set out to assist the visually impaired. Back in 2019 we covered a laser-augmented glove that attempts something very similar.

By some estimates, nearly one billion people worldwide have some degree of visual impairment. Assistive devices like the T.O.F Wristband V2, and others like it, offer these people the potential for greater independence and an improved standard of living.

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