We don’t see many EMG (electromyography) projects, despite how cool the applications can be. This may be because of technical difficulties with seeing the tiny muscular electrical signals amongst the noise, it could be the difficulty of interpreting any signal you do find. Regardless, [hut] has been striving forwards with a stream of prototypes, culminating in the aptly named ‘Prototype 8’

The current prototype uses a main power board hosting an Arduino Nano 33 BLE Sense, as well as a boost converter to pump up the AAA battery to provide 5 volts for the Arduino and a selection of connected EMG amplifier units. The EMG sensor is based around the INA128 instrumentation amplifier, in a pretty straightforward configuration. The EMG samples along with data from the IMU on the Nano 33 BLE Sense, are passed along to a connected PC via Bluetooth, running the PsyLink software stack. This is based on Python, using the BLE-GATT library for BT comms, PynPut handing the PC input devices (to emit keyboard and mouse events) and tensorflow for the machine learning side of things. The idea is to use machine learning from the EMG data to associate with a specific user interface event (such as a keypress) and with a little training, be able to play games on the PC with just hand/arm gestures. IMU data are used to augment this, but in this demo, that’s not totally clear.

All hardware and software can be found on the project codeberg page, which did make us double-take as to why GnuRadio was being used, but thinking about it, it’s really good for signal processing and visualization. What a good idea!

Obviously there are many other use cases for such a EMG controlled input device, but who doesn’t want to play Mario Kart, you know, for science?

Checkout the demo video (embedded below) and you can see for yourself, just be aware that this is streaming from peertube, so the video might be a little choppy depending on your local peers. Finally, if Mastodon is your cup of tea, here’s the link for that. Earlier projects have attempted to dip into EMG before, like this Bioamp board from Upside Down Labs. Also we dug out an earlier tutorial on the subject by our own [Bil Herd.]

Although the widespread use of 3D printers has made things like linear bearings and leadscrews more common, you still can’t run down to your local big-box hardware store and get them. However, you can get drawer slides and any hobby shop can sell you some RC servos. That and an Arduino can make a simple and easy plotter. Just ask [JimRD]. You can also watch it do its thing in the video below.

Of course, servos aren’t usually what you use in a plotter. But the slides convert the rotation of the servo into linear motion. One servo for X and one for Y is all you need. Another microservo lifts the pen up and down using a hinge you could also get from a hardware store.

Is it pretty? No. Does it do amazing artwork? No, again. But it is the kind of thing you could probably throw together from things you happen to have hanging around, especially if you are about to trash an old desk or cabinet with slides in it.

This would make a great rainy day project. We are suckers for simple plotter projects even though you could just mate a pen to your 3D printer or CNC machine. Those won’t fit your whiteboard, though.

Having any kind of shop is pretty great, no matter how large it may be or where it’s located. If the shop is in an outbuilding, you get to make more noise. On the other hand, it will probably get pretty darn hot in the summer without some kind of cooling system, especially if you don’t have a window for a breeze (or a window A/C unit).

[Curtis in Seattle] built an awesome thermal battery-based cooling system for his shop. The battery part consists of five 55-gallon drums full of tap water that are connected in series and buried a foot underground, about two feet out from the wall. There are two radiators filled with water and strapped to 20″ box fans  — one inside the shop, which sends heat from the shop into the water, and another outside that transfers heat out of the water and into the cool night air. Most summer days, the 800-square-foot shop stays at a cool 71°F (21.7°C).

We love that the controls are housed in an old film projector. Inside there’s an Arduino Uno running the show and taking input from four DS18B20 one-wire temperature sensors for measuring indoor, outdoor, battery, and ground temperatures. There are four modes accessible through the LCD menu — idle, cool the shop, recharge mode, and a freeze mode in case the outside temperature plummets. Why didn’t [Curtis in Seattle] use anti-freeze? It’s too expensive, plus it doesn’t usually get that cold. (Although we hear that Seattle got several inches of snow for Christmas.) Check it out after the break.

If you can’t just go burying a bunch of 55-gallon drums in the ground where you live, consider building a swamp cooler out of LEGO.

Thanks for the tip, [Zane Atkins]!

Maybe we’re biased, but we think everyone has a use for a macropad. It’s just a matter of time before a highly personalized set of speed controls starts to sound like a great time-saving device to have around.

Trouble is, macropads are usually kind of expensive to buy outright, and not everyone feels comfortable building keyboards. Okay, so what if you didn’t even have to solder anything? That’s the idea behind [Jan Lunge]’s hand-wired macropad.

You will still want to open a window for ventilation if you build this one, because this macropad requires a lot of 3D printing. What it doesn’t require is glue or screws, because everything snaps together.

Of course, the star of this build is [Jan]’s hot swap socket design. We especially love the little clip that holds the column wires in place while also providing a spacer between those and the row wires. Everything is connected up to a Pro Micro with non-insulated wire and held in place with bends at the ends and the magic of tension. Be sure to check out the build video after the break.

Thirsty for more than a six pack of switches? This design is easy to scale up until you run out of microcontroller inputs. At that point, you might want to add screens to keep track of all your macros.

Thanks for the tip, [BaldPower]!

Tesla is well known for making cars that can accelerate quickly, but there’s always room for improvement. [Warped Perception] decided that his Tesla Model S P85D needed that little bit of extra oomph (despite the 0-60 MPH or 0-97 km/h time of 3.1 seconds), so he did what any sensible person would: add three jet turbines to the back of his car.

The best part of this particular build is the engineering and fabrication that made this happen. With over 200 pieces and almost all personally fabricated, this is a whirlwind of a build. The control panel is first, and there’s a particularly clever technique of 3D printing the lettering directly onto the control panel for the flat stuff. Then for the pieces with angles that would prevent the head from moving freely, he printed onto a plastic sheet in reverse, applied glue, then stuck the letters to the plate as a sheet. A top layer of clear coat ensures the letters won’t come off later.

He installed the control electronics in the trunk with wiring strung from the car’s front to the rear. Three Arduinos serve as controllers for the jets. Afterward, came the bracket to hold the engines and attach it to the car’s underside. Unfortunately, supplies were a little hard to come by, so he had to make do with what was on hand. As a result it didn’t come out as strong as he would have hoped, but it’s still pretty impressive.

[Warped Perception] does a few tests before taking it out on the road. Then, he shifted the car into neutral and could drive the car solely on jet power, which was one of his goals. While we don’t love the idea of testing a jet engine on public roads, it certainly would discourage tailgaters.

Next, he finds a quieter road and does some speed tests. Unfortunately, it was drizzling, and the pavement was damp, putting a damper on his 0-60 standing times. Electric-only he gets 4.38 seconds, and turning on the jets plus electric shaves that down to 3.32 seconds. Overall, an incredible build that’s sure to draw a few curious glances whenever you’re out on the town.

If you’re looking to upgrade your Tesla, perhaps instead of jet engines, you might opt for a robot to plug it in for you?

The holidays always remind us of our favorite toys from when we were kids. Johnny Astro, an Erector set, and — of course — a Spirograph. [CraftDiaries] has an Arduino machine that isn’t quite a Spirograph, but it sure reminds us of one. The Arduino drives two stepper motors that connect to a pen that can create some interesting patterns.

The build uses a few parts that were laser cut, but they don’t look like they’d be hard to fabricate using conventional means or even 3D printing. The author even mentions you could make them out of cardboard or foamboard if you wanted to.

The electronics are straightforward with two stepper drivers. We couldn’t help but think that some of the old 3D printer motherboards we have laying around here could handle this very easily. However, in this project, the CPU is an ordinary UNO with a CNC shield to drive the motors.

Of course, the real trick is the software. Apparently, the different patterns come from the relationship between the delay between steps of the right motor and that of the left motor. There’s got to be some math behind that, but the patterns are certainly pretty.

If you prefer something that looks more like an actual Spirograph, grab a bag of Lego. Or try the Art-O-Matic.

When a new board drops, makers around the planet immediately start hacking new projects with it. Here are 17 fun projects to try on fresh hardware.

The post 17 Fun Projects for New Boards from Raspberry Pi, Arduino, Micro:Bit, and More appeared first on Make: DIY Projects and Ideas for Makers.

Sad news from Germany, with the recent passing of a legend in the crypto community: Mr. Goxx, the crypto-trading hamster. The rodent rose to fame in the crypto community for his trades, which were generated at random during his daily exercise routines — his exercise wheel being used like a roulette wheel to choose a currency, and a pair of tunnels determined whether the transaction would be a buy or sell. His trading career was short, having only started this past June, but he was up 20% over that time — that’s nothing to sneeze at. Our condolences to Mr. Goxx’s owners, and to the community which sprung up around the animal’s antics.

It might seem a little early to start planning which conferences you’d like to hit in 2022, but some require a little more lead time than others. One that you might not have heard of is DINACON, the Digital Naturalism Conference, which explores the intersection of technology and the natural world. The con is set for the entire month of July 2022 and will be held in Sri Lanka. It has a different structure than most cons, in that participants attend for a week or so on a rotating basis, much like a biology field station summer session. It sounds like a lot of fun, and the setting couldn’t be more idyllic.

If you haven’t already killed your holiday gift budget buying NFTs, here’s something you might want to consider: the Arduino Uno Mini Limited Edition. What makes it a Limited Edition, you ask? Practically, it’s the small footprint compared to the original Uno and the castellated edges, but there are a bunch of other extras. Each elegant black PCB with gold silk screening is individually numbered and comes in presentation-quality packaging. But the pièce de résistance, or perhaps we should say the cavallo di battaglia, is that each one comes with a hand-signed letter from the Arduino founders. They honestly look pretty sharp, and at $45, it’s really not a bad collector’s piece.

And finally, the YouTube algorithm giveth again, when this infrastructure gem popped up in our feed. You wouldn’t think there’d be much of interest to see in a water main repair, but you’d be wrong, especially when that main is 50′ (15 m) below the surface, and the repair location is 600′ (183 m) from the access hatch. Oh yeah, and the pipe is only 42″ (1 m) in diameter, and runs underneath a river. There’s just so much nope in this one, especially since the diver has to swim into a special turning elbow just to get pointed in the right direction; how he turns around to swim out is not worth thinking about. Fascinating tidbits include being able to see the gravel used to protect the pipe in the riverbed through the crack in the pipe, and learning that big water mains are not completely filled, at least judging by the small air space visible at the top of the pipe. Those with claustrophobia are probably best advised to avoid this one, but it’s still amazing to see how stuff like this is done.

Who says it’s too early to get in the holiday spirit? We say it’s not. After all, people need time to get in the spirit before it comes and goes. And what better way to count down the days until Christmas than an electronic Advent calendar?

[Tom Goff]’s kids had some pretty cool ideas for building a decoration, like a musical, lighted sleigh complete with robotic Santa Claus. While that’s a little much to pull off for this year, they did salvage the music and lights part for their Hackvent calendar.

There are 24 small LEDs for December 1st through the 24th, and a big white star for December 25th. Each day, the kids just push the button and the day’s LED lights up. On the big day, all the small lights cascade off and the white one lights up, then it plays Jingle Bells through a sound playback module.

Each LED is connected directly to an input on an Arduino Mega. While there are several ways of lighting up 25 LEDs, this one is pretty kid-friendly. We think the coolest part of this build is that [Tom] and the kids did it old school, with nails hammered into the laser-cut plywood and used as connection terminals. Be sure to check it out in action after the break.

The more time you have, the more you can put into your Advent calendar build. Like chocolates, for instance.