Soil Sensor Shows Flip-Dots Aren’t Just For Signs

October 28, 2021 by Donald Papp 13 Comments

Soil sensors are handy things, but while sensing moisture is what they do, how they handle that data is what makes them useful. Ensuring usefulness is what led [Maakbaas] to design and create an ESP32-based soil moisture sensor with wireless connectivity, deep sleep, data logging, and the ability to indicate that the host plant needs watering both visually, and with a push notification to a mobile phone.

A small flip-dot indicator makes a nifty one-dot display that requires no power when idle.

The visual notification part is pretty nifty, because [Maakbaas] uses a small flip-dot indicator made by Alfa-Zeta. This electromechanical indicator works by using two small coils to flip a colored disk between red or green. It uses no power when idle, which is a useful feature for a device that spends most of its time in a power-saving deep sleep. When all is well the indicator is green, but when the plant needs water, the indicator flips to red.

The sensor itself wakes itself up once per hour to take a sensor measurement, which it then stores in a local buffer for uploading to a database every 24 measurements. This reduces the number of times the device needs to power up and connect via WiFi, but if the sensor ever determines that the plant requires water, that gets handled immediately.

The sensor looks great, and a 3D-printed enclosure helps keep it clean while giving the device a bit of personality. Interested in rolling your own sensor? The project also has a page on Hackaday.io and we’ve previously covered in-depth details about how these devices work. Whether you are designing your own solution or using existing hardware, just remember to stay away from cheap probes that aren’t worth their weight in potting soil.

Oscilloscope Clocks: Now In Color!

October 28, 2021 by Adam Zeloof 5 Comments

Ordinarily, when we hear the words “clock” and “oscilloscope” in the same sentence we conjure images of measuring a stable, repeating square wave that acts as the heartbeat of a system. Of course, that’s not the only meaning– there’s a much more fun and less useful one: using an oscilloscope to display the time.

That’s what [Wolfgang Friedrich] set out to do when he cobbled some protoboard, probes, and an FPGA into the Multi Color Oscilloscope Clock. Each digit on the clock is treated like a seven-segment display, made up of three horizontal bars and four vertical bars. The horizontal bars are generated by constant voltage at different levels, and the vertical bars are generated by quickly switching between two voltages. [Wolfgang] decided to use an R-2R resistor ladder DAC to create the appropriate analog signals from the FPGA’s digital outputs. For bonus points, each set of digits (hours, minutes, and seconds) are output concurrently through separate channels, so they can be displayed in different colors on the screen of his four-channel scope (the fourth channel is used for the points between numbers).

Misusing oscilloscopes in the name of fun has become a time-honored tradition– from Tennis for Two back in 1958 (which later became the beloved Pong) to the plethora of analog o-scope clocks we’ve seen, it’s clear that hackers just can’t get enough of the unique vector display style that a scope can provide. We love [Wolfgang]’s idea of using the scope’s channels to create a multi-color display, and we’re left wondering what kind of wacky waveforms we’ll be seeing next.

Eye-Tracking Device Is A Tiny Movie Theatre For Jumping Spiders

October 28, 2021 by Donald Papp 18 Comments

The eyes are windows into the mind, and this research into what jumping spiders look at and why required a clever device that performs eye tracking, but for jumping spiders. The eyesight of these fascinating creatures in some ways has a lot in common with humans. We both perceive a wide-angle region of lower visual fidelity, but are capable of directing our attention to areas of interest within that to see greater detail. Researchers have been able to perform eye-tracking on jumping spiders, literally showing exactly where they are looking in real-time, with the help of a custom device that works a little bit like a miniature movie theatre.

A harmless temporary adhesive on top (and a foam ball for a perch) holds a spider in front of a micro movie projector and IR camera. Spiders were not harmed in the research.

To do this, researchers had to get clever. The unblinking lenses of a spider’s two front-facing primary eyes do not move. Instead, to look at different things, the cone-shaped inside of the eye is shifted around by muscles. This effectively pulls the retina around to point towards different areas of interest. Spiders, whose primary eyes have boomerang-shaped retinas, have an X-shaped region of higher-resolution vision that the spider directs as needed.

So how does the spider eye tracker work? The spider perches on a tiny foam ball and is attached — the help of a harmless and temporary adhesive based on beeswax — to a small bristle. In this way, the spider is held stably in front of a video screen without otherwise being restrained. The spider is shown home movies while an IR camera picks up the reflection of IR off the retinas inside the spider’s two primary eyes. By superimposing the IR reflection onto the displayed video, it becomes possible to literally see exactly where the spider is looking at any given moment. This is similar in some ways to how eye tracking is done for humans, which also uses IR, but watches the position of the pupil.

In the short video embedded below, if you look closely you can see the two retinas make an X-shape of a faintly lighter color than the rest of the background. Watch the spider find and focus on the silhouette of a tasty cricket, but when a dark oval appears and grows larger (as it would look if it were getting closer) the spider’s gaze quickly snaps over to the potential threat.

Feel a need to know more about jumping spiders? This eye-tracking research was featured as part of a larger Science News article highlighting the deep sensory spectrum these fascinating creatures inhabit, most of which is completely inaccessible to humans.

Continue reading “Eye-Tracking Device Is A Tiny Movie Theatre For Jumping Spiders” →

Four More Talks Added To The 2021 Remoticon Lineup

October 28, 2021 by Tom Nardi 1 Comment

We’ve already unveiled multiple keynote speakers and a slate of fascinating presenters that will be showing off everything from reverse engineering vintage calculators to taking those first tentative steps on your CAD journey for this year’s Remoticon. You’d be forgiven for thinking that’s everything you’ll see at the conference, but there’s still plenty to announce before the two-day virtual event kicks off on November 19th. Normally we’d be promising to make sure you get your money’s worth, but since tickets are completely free, we’re shooting a bit higher than that.

We were blown away by the number of fantastic talk proposals we received during this year’s extended call. Let’s take a look at the next four presenters who will be joining us for the 2021 Hackaday Remoticon on November 19th through the 20th.

Continue reading “Four More Talks Added To The 2021 Remoticon Lineup” →

GamecubePC Puts a PC into a Gamecube chassis

GamecubePC Packs Plenty Of Punch Into GameCube Plastics

October 28, 2021 by Ryan Flowers 2 Comments

If reading Hackaday teaches us anything, it’s that there is a subset of hackers who take things like emulator builds a step farther than most. [RetroModder] is very clearly one such hacker. Enter the GamecubePC, which you can read about on Hackaday.io. The GamecubePC is a multi-year project that aims to stuff an entire Windows 10 PC into a GameCube shell while still being able to play Wii and GameCube titles at native resolution and performance.

Internals of the GamecubePC with all the custom chassis and PCB's on display — Internals of the GamecubePC with all the custom chassis and PCB’s on display

Although it only takes a spare computer and the Dolphin emulator to make a GameCube and Wii emulator, great attention has been paid to keeping the GameCube at the forefront. Contributing to the illusion is the preservation of the original GameCube power switch and reset buttons by way of custom PCB’s that interface the parts to the mSTX motherboard.

The bottom of the GameCube shell is replaced with a 3D printed base that mounts the motherboard while smartly giving access to the motherboard’s front panel. The minuscule motherboard sports an Intel Core™ i5-7600 with 8GB memory, and SSD storage. Topping off the experience are four functional controller ports that can be switched to be used with the emulator or with PC games too. Surely the GamecubePC will be the subject of many double takes!

Custom game builds are no stranger to Hackaday, and you might appreciate this portable Wii that can play Wii and GameCube games or this GameCube controller hacked into a Joycon for the Nintendo Switch.

Edit from the far future: it’s now a project on Tindie. Check it out.

Speaker ‘Stun Gun’ Aims To Combat China’s Dancing Grannies

October 28, 2021 by Lewin Day 74 Comments

One of the more popular social activities in China is group dancing in public squares. Often the pastime of many middle-aged and older women, participants are colloquially referred to as “dancing grannies.” While the activity is relatively wholesome, some dancers have begun to draw the ire of their neighbourhoods with their loud music and attempts to dominate the use of public parks and recreational areas.

Naturally, a technological solution sprung up promising to solve the problem. The South China Morning Post has reported on a “stun gun” device which claims to neutralise speakers from a distance, in an effort to shut down dance gatherings. The device created a huge stir on social media, as well as many questions about how it could work. It’s simpler, and a bit less cool, than you think. Continue reading “Speaker ‘Stun Gun’ Aims To Combat China’s Dancing Grannies” →

Really Robotic Robot Costume Will Probably Win The Contest

October 28, 2021 by Kristina Panos 8 Comments

Still don’t have anything to wear to that Halloween party this weekend? Or worse, your kid hasn’t decided on a costume that you both can agree on? Well, look no further than [Natasha Dzurny]’s Sally Servo the Really Robotic Robot Costume and accompanying multi-part build guide. You might want to start by raiding that recycle bin for cardboard, because you’re going to need a lot of it.

What you won’t need a lot of is hard-to-source parts, at least if you build it the [Natasha] and Brown Dog Gadgets way. Even so, there are a ton of cool moving and blinking bits and bobs to be made with servos, LEDs, and RGB LEDs connected up to something kid-friendly like the Micro:bit and the Brown Dog Gadgets Bit Board — that’s a base for the :bit that lets users connect components via LEGO and conductive tape.

Between Sally’s robotic googly eyes and her light-up belt, there are plenty of ideas here to steal and make your own, and each one is packaged in a great-looking guide complete with paper printing templates.

Our favorite part has to be the infinity mirror heart, which appears to be beating thanks to clever programming. That, and the costume details, like the waist-area wires running between the upper and lower pieces.

Is the party at your house? There’s probably still enough time to put together a projector-based stomping game for the driveway.