A word of warning: Google for the definition of the word “pummer” at your own risk. Rest assured that this beautiful solar-powered circuit sculpture fits the only definition of pummer that we care to deal with.
For the unfamiliar, a pummer is a device from the BEAM style of robotics, a sort of cyborg plant that absorbs solar energy during the day and turns it into a gently pulsating light that “pumms” away the dark hours.
[Mohit Bhoite]’s take on the pummer is an extraordinary model of a satellite executed mainly in brass rod. His attention to detail on the framework boggles our minds; we could work for days on a brass rod and never achieve the straight lines and perfect corners he did. The wings support two solar cells, while the hull of the satellite holds a dead-bugged 74HC240 octal buffer/line-driver chip and all the other pumm-enabling components. A one farad supercap – mounted to look like a dish antenna – is charged during the day and a single LED beacon blinks into the night.
No schematic is provided, but there are probably enough closeup shots to reverse engineer this, which actually sounds like a fun exercise. (Or you can cheat and fetch the PDF copy of the old Make magazine article that inspired him.)
Hats off to [Mohit] for a top-notch circuit sculpture. We’ve seen similarly detailed and well-executed sculptures from him before; something tells us this won’t be the last.
Thanks to [Varun Reddy] for the tip.
It’s been a project filled with fits and starts, and it very nearly ended up as a “Fail of the Week” feature, but we’re happy to report that the [Thought Emporium]’s desktop WiFi radio telescope finally works. And it’s pretty darn cool.
If you’ve been following along with the build like we have, you’ll know that this stems from a previous, much larger radio telescope that [Justin] used to visualize the constellation of geosynchronous digital TV satellites. This time, he set his sights closer to home and built a system to visualize the 2.4-GHz WiFi band. A simple helical antenna rides on the stepper-driven azimuth-elevation scanner. A HackRF SDR and GNU Radio form the receiver, which just captures the received signal strength indicator (RSSI) value for each point as the antenna scans. The data is then massaged into colors representing the intensity of WiFi signals received and laid over an optical image of the scanned area. The first image clearly showed a couple of hotspots, including a previously unknown router. An outdoor scan revealed routers galore, although that took a little more wizardry to pull off.
The videos below recount the whole tale in detail; skip to part three for the payoff if you must, but at the cost of missing some valuable lessons and a few cool tips, like using flattened pieces of Schedule 40 pipe as a construction material. We hope to see more from the project soon, and wonder if this FPV racing drone tracker might offer some helpful hints for expansion.
Continue reading “Desktop Radio Telescope Images The WiFi Universe”
There’s something iconic about dish antennas. Chances are it’s the antenna that non-antenna people think about when they picture an antenna. And for many applications, the directionality and gain of a dish can really help reach out and touch someone. So if you’re looking to tap into a distant WiFi network, this umbrella-turned-dish antenna might be just the thing to build.
Stretching the limits of WiFi connections seems to be a focus of [andrew mcneil]’s builds, at least to judge by his YouTube channel. This portable, foldable dish is intended to increase the performance of one of his cantennas, a simple home-brew WiFi antenna that uses food cans as directional waveguides. The dish is built from the skeleton of an umbrella-style photographer’s flash reflector; he chose this over a discount-store rain umbrella because the reflector has an actual parabolic shape. The reflective material was stripped off and used as a template to cut new gores of metal window screen material. It’s considerably stiffer than the reflector fabric, but it stretches taut between the ribs and can still fold up, at least sort of. An arm was fashioned from dowels to position the cantenna feed-horn at the focus of the reflector; not much detail is given on the cantenna itself, but we assume it’s similar in design to cantennas we’ve featured before.
[andrew] hasn’t done rigorous testing yet, but a quick 360° scan from inside his shop showed dozens of WiFi signals, most with really good signals. We’ll be interested to see just how much this reflector increases the cantenna’s performance.
Continue reading “Umbrella and Tin Cans Turned into WiFi Dish Antenna”
I was splitting wood one day a few years back, getting next winter’s firewood ready on my hydraulic splitter. It normally handled my ash and oak with ease, but I had a particularly gnarly piece of birch queued up, and the splitter was struggling. The 20-ton cylinder slowed as the wedge jammed in the twisted grain, the engine started to bog down, then BANG! I jumped back as something gave way and the engine revved out of control; I figured a hydraulic hose gave out. Whatever it was, I was done for the day.
I later discovered that a coupler between the engine shaft and the hydraulic pump failed dramatically. It was an easy fix once I ordered the right part, and I’ve since learned to keep extras in stock. Couplings are useful things, and they’re the next up in our series on mechanisms.
Continue reading “Mechanisms: Couplings”
All the kids down at Stanford are talking about neural nets. Whether this is due to the actual utility of neural nets or because all those kids were born after AI’s last death in the mid-80s is anyone’s guess, but there is one significant drawback to this tiny subset of machine intelligence: it’s a complete abstraction. Nothing called a ‘neural net’ is actually like a nervous system, there are no dendrites or axions and you can’t learn how to do logic by connecting neurons together.
NeruroBytes is not a strange platform for neural nets. It’s physical neurons, rendered in PCBs and Molex connectors. Now, finally, it’s a Kickstarter project, and one of the more exciting educational electronic projects we’ve ever seen.
Regular Hackaday readers should be very familiar with NeuroBytes. It began as a project for the Hackaday Prize all the way back in 2015. There, it was recognized as a finalist for the Best Product, Since then, the team behind NeuroBytes have received an NHS grant, they’re certified Open Source Hardware through OSHWA, and there are now enough NeuroBytes to recreate the connectome of a flatworm. It’s doubtful the team actually has enough patience to recreate the brain of even the simplest organism, but is already an impressive feat.
The highlights of the NeuroBytes Kickstarter include seven different types of neurons for different sensory systems, kits to test the patellar reflex, and what is probably most interesting to the Hackaday crowd, a Braitenberg Vehicle chassis, meant to test the ideas set forth in Valentino Braitenberg’s book, Vehicles: Experiments in Synthetic Psychology. If that book doesn’t sound familiar, BEAM robots probably do; that’s where the idea for BEAM robots came from.
It’s been a long, long journey for [Zach] and the other creators of NeuroBytes to get to this point. It’s great that this project is now finally in the wild, and we can’t wait to see what comes of it. Hopefully a full flatworm connectome.
One of the takeaway ideas that we got from BEAM robotics was the idea that the machine itself, rather than tons of processing power, can do a lot. Your hand affords gripping, and humans have made a pretty good living out of manipulating things (he says, typing). None of this is about the brain; it’s all about the mechanism.
Which brings us to the one-motor “Runner” robot. We’ll admit that we were a little bit disappointed to see that it doesn’t run so much as hop, flop, or scoot along on the two legs and that front wheel-nose. Still, it’s an awesome mechanism, and gets the locomotion job done in a very theatrical way. We’re left wondering if using two motors would allow it to steer or just flip over and flail around on its back. Going to a six “leg” design will definitely get the job done, as demonstrated by Boston Dynamics RHex robot.
Continue reading “Simplest Jumping Kangaroo Bot”
We’ve heard reports that internet connectivity in Australia can be an iffy proposition, and [deandob] seems to back that up. At the limit of a decent DSL connection and on the fringe of LTE, [deandob] decided to optimize the wireless connection with this homebrew Yagi antenna.
Officially known as the Yagi-Uda after its two Japanese inventors from the 1920s, but generally shortened to the name of its less involved but quicker to patent inventor, the Yagi is an antenna that provides high gain in one direction. That a homebrew antenna was even necessary at all is due to [deandob]’s ISP using the 2300MHz band rather than the more popular 2400MHz – plenty of cheap 2.4GHz antennas out there, but not so much with 2.3GHz. With multiple parallel and precisely sized and spaced parasitic elements, a Yagi can be a complicated design, but luckily for [deandob] the ham radio community has a good selection of Yagi design tools available. His final design uses an aluminum rod for a boom, 2mm steel wire for reflectors and directors, and a length of coax as the driven element. The result? Better connectivity that pushes his ISP throttling limit, and no more need to mount the modem high enough in his house to use the internal antenna.
People on the fringes of internet coverage go to great lengths to get connections, like this off-grid network bridge. Or if you’d rather use a homebrew Yagi to listen to meteors, that’s possible too.