When you’re a kid, nothing says spooky like turning off the lights and bringing out the Ouija board. For decades, this mystifying oracle has purported to channel the dead by spelling out messages using a board with numbers, letters, yes/no, and a heart-shaped windowed bit of plastic called a planchette.
While the action of a standard Ouija board owes itself to something called the ideomotor phenomenon, this motorized Ouija robot by [Ronald McCollum] is powered by tweets.
That’s right, the mannequin hand uses the planchette to spell out the tweets with a rather crisp snap of the wrist. [Ronald] impressively coded all the positions by hand, with each letter being comprised of both a hand position and planchette position.
This project utilizes both an Adafruit Crickit board and a Raspberry Pi, mostly because [Ronald] wanted to use the Crickit for something, and added the Pi to spell out the tweets on the display in real time. Check it out in action after the break, and stick around for a bonus video of the numbers being laser-cut.
While renewable energy offers many opportunities for decentralizing energy production, it can sometimes feel that doing so on a truly local level remains unachievable with increasingly large utility-scale deployments re-centralizing the technology. [AdamEnt] hopes to help others seize the means of energy production with the development of the ModuCoil.
This modular coil is intended to be used in motor and generator applications, and features a 3D printed structure to wind your copper about as well as a series of ferromagnetic machine screws and nuts meant to boost the field strength. This project really emphasizes the rapid part of rapid prototyping with this version 2 of the coil following only a week after the first.
[AdamEnt] only reached a peak of ~600 mV in the short test of a single coil, but is optimistic the current design could hit 1V/coil given a fully wound coil actually affixed to something instead of just held in his hand. It’s definitely early stages, but we think this could be the start of an interesting ecosystem of motor and generator designs.
In the world of agriculture, not all enterprises are large arable cropland affairs upon which tractors do their work traversing strip by strip under the hot sun. Many farms raise far more intensive crops on a much smaller scale, and across varying terrain. When it comes to automation these farms offer their own special challenges, but with the benefit of a smaller machine reducing some of the engineering tasks. There’s an entry in this year’s Hackaday prize which typifies this, [KP]’s Agrofelis robot is a small four-wheeled carrier platform designed to deliver autonomous help on smaller farms. It’s shown servicing a vineyard with probably one of the most bad-ass pictures you could think of as a pesticide duster on its implement platform makes it look for all the world like a futuristic weapon.
A sturdy tubular frame houses the battery bank and brains, while motive power is provided by four bicycle derived motorized wheels with disk brakes. Interestingly this machine steers mechanically rather than the skid-steering found in so many such platforms. On top is a two degrees of freedom rotating mount which serves as the implement system — akin to a 3-point linkage on a tractor. This is the basis of the bad-ass pesticide duster turret mentioned above. Running it all is a Nvidia Jetson Nano, with input from a range of sensors including global positioning and LIDAR.
The attention to detail in this agricultural robot is clearly very high, and we could see machines like it becoming indispensable in the coming decades. Many tasks on a small farm are time-consuming and involve carrying or wheeling a small machine around performing the same task over and over. Something like this could take that load off the farmer. We’ve been there, and sure would appreciate something to do the job.
There are too many different kinds of displays – some of them, you already know. I’d like to help you navigate the hobbyist-accessible display world – let’s take a journey together, technology by technology, get a high-level overview of everything you could want to know about it, and learn all the details you never knew you needed to know. In the end, I’d like you to be able to find the best displays for any project you might have in mind, whatever it could be.
Today, let’s take a look at a well-known LCD technology – the HD44780 displays, a type of display that we hobbyists have been working with since the 1980s. Its name comes from the HD44780 driver chip – a character display driver IC that connects to a raw display panel and provides an easy interface. HD44780 displays are not known for power efficiency, cutting-edge technology, ultimate flexibility, or small size, for that matter. However, they’re tried and true, easy to drive, require little to no computing power on your MCU, and you will be able to buy them for the foreseeable future. They’re not about to get taken off the market, and they deserve a certain kind of place in our parts boxes, too.
If you work with HD44780 displays for a project or two, you might acquire a new useless superpower – noticing just how many HD44780 displays are still in use in all sorts of user-facing devices, public or private. Going out and about in your day-to-day life, you can encounter a familiar 16 x 2 grid of characters in cash registers, public transport ticket machines, home security panels, industrial and factory equipment, public coffee machines, and other microcontroller-assisted places of all kinds! Continue reading “Displays We Love Hacking: The HD44780 Family”→
We’re going to go out on a limb here and guess that a fair number of Hackaday readers went through a phase of model building growing up. To further push out that branch, we’ll further guess that some of those models included spacecraft, both real and imaginary. And with good reason — you don’t get to space without some interesting engineering, a lot of which is reflected in the design of the vehicles intended to get there. Rockets are cool, satellites are cooler still, and if you can’t actually go to space yourself, or at least be the person building the actual hardware, at least you can build a model and dare to dream.
But while a model on a stand or hanging from the ceiling on fishing line can certainly stimulate the imagination, wouldn’t it be better if a model did something? Bryan Murphy and Sam Treadgold think so, which is why they’ve been working on the “ISS Mimic,” which we recently featured. The 3D-printed 1:100 scale model of the International Space Station is equipped with servos that move the station’s solar panels in real-time based on publically available telemetry. It’s way more engaging than a static model, especially for kids just getting into STEM and related fields.
Bryan and Sam will stop by the Hack Chat to talk not just about the ISS Mimic, but about everything that has to do with modeling space. Who wouldn’t love a desktop version of a Martian or lunar rover keeping pace with its full-scale counterpart? And wouldn’t it be great to be able to visualize just how far away Voyager is right now? If it’s out there, we should be able to bring it home, at least in model form.
Although we generally think of Internet of Things (IoT) and similar devices as things that are scattered around above ground, there are plenty of reasons to also have such devices underground. These so-called IoUT devices are extremely useful when it comes to monitoring underground structures, but communication via radiowaves is obviously impacted when soil is in the way. Although there are ways to get around this, a 2022 paper by Maja Škiljo and colleagues in Sensors covers an interesting way to make use of this signal attenuation property of changing moisture levels in soil.
By quantifying the exact attenuation of the signal received at the gateways, they were able to determine the soil moisture levels around the LoRa node which had been buried at a depth of approximately 14 centimeters. This LoRa node used off-the-shelf components consisting of an ATmega328P-based Arduino Pro Mini and SX1276-based RFM95W LoRa module with a spring antenna.
During experimentation in- and outdoors it was determined that a narrowband, printed (PCB) antenna was optimal for soil moisture sensing purposes. Other than the interesting question of how to keep soil moisture sensing nodes like this powered up over long periods of time (perhaps periodic retrieval to replenish the battery), this would seem to be a very interesting way to monitor the soil moisture levels in something like a field, where each node can provide its own ID and the received signal providing the relevant data in the form of the SNR and other parameters recorded by the gateway.
(Heading image: The measurement results of: (a) RSSI in dBm collected from gateway 2 and (b) soil moisture during the winter period. (Credit: Maja Škiljo et al., 2022) )
The walking tank concept has always captured imaginations. Whether you’re talking about the AT-AT walkers of Star Wars, or the Dreadnoughts from Warhammer 40,000, they are often portrayed in fiction as mighty and capable foes on the battlefield. These legged behemoths ideally combine the firepower and defense of traditional tanks with the versatility of a legged walking frame.
Despite their futuristic allure, walking tanks never found a practical military application. Let’s take a look at why tracks still rule, and why walking combat machines are going to remain firmly in the realm of fiction for the foreseeable future.