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Hackaday Prize 2023: Ubo Project: Building For Builders

August 24, 2023 by 7 Comments

The Ubo Pod by [Mehrdad Majzoobi] is a very highly polished extension pack and enclosure for the Raspberry Pi 4, which shows you how far you can go to turn a bare PCB into something that rivals the hardware offerings from Google and others. Gadgets like the Sonos speakers and Amazon or Google’s covert listening devices (aka Echo, Alexa, or whatever they’re branded as) are fun to play with. Still, the difficulty of hacking custom applications into them and god-forbid adding one’s own extension hardware, makes them fairly closed ecosystems. Add in the concerns of privacy and data security; they look less and less attractive the closer you look. Luckily the Raspberry Pi and its friends have improved the accessibility to the point where it’s positively easy to create whatever you want with whatever hardware you need, and to that end we think [Mehrdad] has done a splendid job.

The custom top PCB sits below the wooden top surface, hosting a central LCD display with push buttons located around it. Also sitting atop are some IR transmitters and receivers as well as RGB LEDs for the ring lighting. This top PCB acts as a RPi hat, and plugs into an RPi4 below, which then attaches to a side board via some PCB-mounted connectors, matching up with the USB and audio connectors. This board seems to act purely as an interconnect and form-factor adaptor allowing interfaces to be presented more conveniently without needing wires. This makes for a very clean construction. Extensive use of resin printing is shown, with lots of nice details of how to solve problems such as LED diffusion and bleeding. Overall, a very slick and well-executed project, that is giving us a few ideas for our own projects.

This type of project is commonplace on these fair pages, like this DIY smart speaker for example. With the supply of pi being still a little difficult to deal with, could you roll your own or get an alternative? What about just using your old mobile phone?

The HackadayPrize 2023 is Sponsored by:

Angry Robot Face Is Less Than Friendly

August 17, 2023 by 10 Comments

Sometimes you just need to create a creepy robot head and give it an intimidating personality. [Jens] has done just that, and ably so, with his latest eerie creation.

The robot face is introduced to us with a soundtrack befitting Stranger Things, or maybe Luke Million. The build was inspired by The Doorman, a creepy art piece with animatronic eyes. [Jens’] build started with a 3D model of a 3D mask, with the eyes and mouth modified to have rectangular cutouts for LED displays. The displays are run by a Raspberry Pi Pico, which generates a variety of eye and mouth animations. It uses a camera for face tracking, so the robot’s evil eyes seem to follow the viewer as they move around. In good form, the face has a simple switch—from good to evil, happy to angry. Or, as [Jens] designates the modes: “Fren” and “Not Fren.”

[Jens] does a great job explaining the build, and his acting at the end of the video is absolutely worth a chuckle. Given Halloween is around the corner, why not build five to eight of these, and hide them in your roommate’s bedroom?

Video after the break.
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PentaBlinky – When One LED Is Not Blinky Enough

August 10, 2023 by 4 Comments

[michimartini] over on Hackaday.io loves playing with multivibrator circuits, and has come across a simple example of a ring oscillator. This is a discrete transistor RC-delay design utilizing five identical stages, each of which has a transistor that deals with charging and discharging the timing capacitor, passing along the inverted signal to its nearest neighbor. The second transistor isn’t strictly needed and is only there to invert the signal in order to drive the LED. When the low pulse passes by the LED lights, without it you’d see all the LEDs lit bar one, which doesn’t look as good.

Compare this with an astable multivibrator to understand how it works

Essentially this circuit is just the classic astable multivibrator circuit that has been split in half and replicated so that the low pulse propagates through more stages than just the two, but thinking about it as a single stage doesn’t work so well until you draw in a couple of neighbors to help visualize the behavior better.

[michimartini] does lament that the circuit starts up in a chaotic fashion and needs a quick short applying to one transistor element in order to get it to settle into a steady rhythm. Actually, that initial behaviour could be interesting in itself, especially as the timing changes with voltage and temperature.

Anyway, we like the visual effect and the curvy organic traces. It would make a neat pin badge. Since we’re thinking about blinkies, here are couple of somewhat minimalist attempts, the world’s smallest blinky, and an even smaller one. Now, who doesn’t love this stuff?

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Got Fireflies? Try Talking To Them With A Green LED

August 6, 2023 by 25 Comments

[ChrisMentrek] shares a design for a simple green LED signal light intended for experiments in “talking” to fireflies. The device uses simple components like PVC piping and connectors to make something that resembles a signal flashlight with a momentary switch — a device simple enough to make in time for a little weekend experimenting.

Observe and repeat flashing patterns, and see if any fireflies get curious enough to investigate.

Did you know that fireflies, a type of beetle whose lower abdomen can light up thanks to a chemical reaction, flash in patterns? Many creatures, fireflies included, are quite curious under the right circumstances. The idea is to observe some fireflies and attempt to flash the same patterns (or different ones!) with a green LED to see if any come and investigate.

[ChrisMentrek] recommends using a green LED that outputs 565 nm, because that is very close to the colors emitted by most fireflies in North America. There’s also a handy link about firefly flashing patterns from the Massachusetts Audubon society’s Firefly Watch program, which is a great resource for budding scientists.

If staying up and learning more about nocturnal nightlife is your thing, then in between trying to talk to fireflies we recommend listening for bats as another fun activity, although it requires a bit more than just a green LED. Intrigued? Good news, because we can tell you all about the different kinds of bat detectors and what you can expect from them.

A Faulty Keyboard From A Single LED

July 5, 2023 by 19 Comments

When the chance arrived to buy a mechanical keyboard for not a lot, naturally, [Hales] jumped at it. Then it started having odd intermittent problems with some keys appearing stuck, which led to a teardown and some fault finding. The culprit was a white LED — but why this was the case is a fascinating story.

Stripping it down there didn’t seem to be an obvious culprit, but eventually, the trail led to a lack of diodes in the matrix. This keyboard had an extremely clever yet rather cursed design in which it used LEDs as both illumination and as a diode in the keyboard matrix circuit, and the faulty LED had a reverse breakdown condition that could be triggered under certain operational conditions.

More unexpectedly, it would sometimes hold on to its reverse breakdown state even after power off. Just when you think you understand a component’s properties, there’s always room for surprise. And we can safely say we’ve learned something about the design of cheaper keyboards in reading the account. It’s clear that when it comes to ‘boards, it’s best to take no chances.

Do-Everything LED Indicator Light Runs From 4V To 60V

June 28, 2023 by 31 Comments

If you’re working with 3.3V or 5V circuits, it’s easy for you to throw on a power or status LED here or there. [Tom Gralewicz] has found himself in a pickle, though, often working on projects with voltages like 36V or 48V. Suddenly, it’s no longer practical to throw an LED and a resistor on a line to verify if it’s powered or not. Craving this simplicity, [Tom] invented the Cheap Universal LED Driver, or CULD, to do the job instead.

The CULD is designed as a simple LED indicator that will light up anywhere from 5V to 50V. It’s intended to be set-and-forget, requiring no fussing with different resistor values and no worries for the end user that excessive current draw will result.

The key part ended up being the LV2862XLVDDCR – a cheap switching regulator. It can output 1 mA to 600 mA to drive one or several LEDs, and it can do so anywhere from a 4V to 60V input. Assemble this on a coin-sized PCB with some LEDs, and you’ve got your nifty do-everything indicator light. With a bridge rectifier onboard, it’ll even work on AC circuits, too.

[Tom] has built a handful himself, but he open-sourced the design in the hopes it will go further. By his calculations, it would be possible to build these in quantities of 1000 for a BOM cost of less than $0.50 each, not counting assembly or the PCB itself. We’d love to see them become a standard part of hacker toolkits, too. If you’ve got a pick-and-place plant that’s looking for work this week, maybe get them on to something like this and see what you can do! If it turns out to be a goer, maybe drop us a note on the tipsline, yeah?

Electronic Earrings Are PCB Art You Can Wear

June 24, 2023 by 4 Comments

If there’s one area of the human anatomy we rarely try to draw the eye, it’s the ears. Nonetheless, [DIY GUY Chris] has developed some LED earrings that should do exactly that.

The earrings are made using PCBs as the very body of the jewelry itself. The PCBs for each ear play host to eight WS2812 LEDs in a tiny 2020 form factor. The LEDs get their instructions from an ATtiny13-A AVR microcontroller, with some further supporting hardware to get everything playing happily together. Each earring runs off a single CR1220 coin cell, which sits on the obverse side of the earring to stay out of sight. The earrings are programmed with pogo pins to avoid the need for any bulky connectors.

By virtue of the tiny addressable LEDs, the earrings are capable of displaying full RGB colors. [DIY GUY Chris] has programmed the earrings with simple color fades, as well  as some fancier chase animations as well.

We’ve seen some great PCB jewelry before, too. Video after the break.

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