3D Printed Hat Blasts The Rain Away

September 11, 2021 by Dave Rowntree 32 Comments

Some ideas are so bad that we just try them anyway, at least that seems to be [Ivan Miranda]’s philosophy. No stranger to just totally ignoring the general consensus on what you can (or at least should) or can’t make with a 3D printer, and just getting on with it, [Ivan] may have gone a little too far this time. Since umbrellas are, well, boring, why not try to keep dry with an air-curtain hat?

As you’ll see from the video, attempting to 3D print an impeller to run from a BLDC motor didn’t exactly go well. The imbalance due to imperfections in the printing process (and lack of an easy way balance it post-print) caused incredibly unpleasant (and possibly damaging) vibrations directly into his skull, not to mention the thing self-disassembling in a short time.

Not to be discouraged, he presses on regardless, substituting an electrical ducted fan (EDF), increasing the silliness-factor oh-so-little, after all as he says “I think I have a solution for all the issues — more power!”

EDFs and other kinds of ducted fans are used in many applications nowadays. Thanks to advances in rare-earth magnets enabling more powerful brushless motors, combined with cheap and accessible control systems, there has never been a better time to drop an EDF into your latest madcap idea. We have covered many ducted fan projects over the years, including this great video about how ducted fans work, which we think is well worth a watch if you’ve not already done so.

The “rain in spain, stays mainly in the plain” doesn’t actually reflect reality, as most rainfall is actually recorded in the mountainous north, rather than the central ‘plain’, But regardless, it never rains when you want it to, certainly in the Basque country where [Ivan] is based. Initial testing was done with a hose pipe, in the shop, which shows a certain dedication to the task in hand to say the least.

He does demonstrate it appearing to actually work, but we’re pretty sure there is still plenty of room for improvement. Although, maybe it’s safer to just shelve it and move on the next mad-cap idea?

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Interactive LED Shoes That Anyone Can Build!

September 5, 2021 by Lewin Day 3 Comments

Normally when we see blinky projects these days, it’s using addressable LED strips with WS2812Bs, or similar alternatives. However, old-school blobby round LEDs are still on the market, and can still be put to great use. These DIY LED shoes from [TechnoChic] are an excellent example of just that.

The shoes use big 10mm LEDs that have color-changing smarts baked in. Simply power them up and they’ll fade between a series of colors. They’re run from a coin cell sewn on to the side of each shoe, with the LEDs jammed into the rear of the sole. A conductive product called Maker Tape is then used to create a circuit for the LEDs and the coin cell, along with a pressure switch inside each shoe. When the wearer puts weight on their heel, the switch conducts, lighting up the LEDs as the wearer takes each step.

This isn’t the first time we’ve seen a pair of shoes bedazzled with LEDs, but it’s arguably the easiest version of the concept to grace these pages. This is a quick way to create interactive flashing LED gadgets, and a great way for beginner makers to jazz up their projects.

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Wearable Scope Lets Your Fingers Do The Probing

September 3, 2021 by Tom Nardi 14 Comments

For frantic hacking sessions where seconds count, this forearm mounted oscilloscope with fingertip probes built by [aniketdhole] might be just what you need. Well, maybe. It’s not immediately clear why you might want to wear an oscilloscope on your arm, and sticking your fingers inside of powered up electronic devices sounds specifically like something your mother probably told you not to do, but here it is anyway.

The scope consists of an nRF5340 evaluation board in a 3D printed mount, with an SPI-connected Adafruit 2.8″ TFT display on top. With a pair of wires run from the board’s ADC and ground pins, [aniketdhole] just needed a bit of code to glue it all together and show some basic signal visualizations on the display. It’s been tested against PWM signals generated by an Arduino and some potentiometer controlled voltages, but anything much wilder than that is probably a bit too much to ask for from this rig in its current configuration.

In the future, [aniketdhole] wants to add some step-down circuity so you can probe higher voltages than the nRF5340 can handle normally, as well as a shunt to allow current measurement. Once the hardware is in place, the next order of business will be an improved touch-capable user interface that lets the user adjust settings and switch between functions.

Even if you’re not sold on the idea of an arm-mounted oscilloscope, this is still an interesting platform for general wearable experimentation. Throw enough sensors into it, and we’re sure there’s more than a few hackers who wouldn’t mind strapping one of these on.

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.