A macro keypad making music.

Meet The Marvelous Macro Music Maker

Do you kind of want a macropad, but aren’t sure that you would use it? Hackaday alum [Jeremy Cook] is now making and selling the JC Pro Macro on Tindie, which is exactly what it sounds like — a Pro Micro-based macro keypad with an OLED screen and a rotary encoder. In the video below, [Jeremy] shows how he made it into a music maker by adding a speaker and a small solenoid that does percussion, all while retaining the original macro pad functionality.

[Jeremy]’s original idea for a drum was to have a servo seesawing a chopstick back and forth on the table as one might nervously twiddle a pencil. That didn’t work out so well, so he switched to the solenoid and printed a thing to hold it upright, and we absolutely love it. The drum is controlled with the rotary encoder: push to turn the beat on or off and crank it to change the BPM.

To make it easier to connect up the solenoid and speaker, [Jeremy] had a little I²C helper board fabricated. There’s one SVG connection and another with power and ground swapped in the event it is needed. If you’re interested in the JC Pro Macro, you can pick it up in various forms over on Tindie. Of course, you might want to wait for version 2, which is coming to Kickstarter in October.

There are many ways to make a macro keyboard. Here’s one that also takes gesture input.

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Can The Solenoid Engine Power A Car?

[Emiel] aka [The Practical Engineer] makes all kinds of fun projects in his fully-featured shop, and one of his tangents has been building a series of solenoid engines. These engines mimic the function of an internal combustion engine, with each solenoid acting as a piston. The only problem with [Emiel]’s concept engines, though, was that he never actually put them into a vehicle to prove their effectiveness. This build finally proves that they can work at powering a vehicle.

The project starts with a new engine. [Emiel] chose a V4 design using four solenoids and an Arduino-based controller. After some trouble getting it to operate properly, he scavenged a small circuit board he built in his V8 solenoid engine to help with timing. With that installed, the solenoids click away and spin the crankshaft at a single constant speed. The vehicle itself was mostly 3D printed, with two aluminum tubes as support structures to mount the engine. Even the wheels were 3D printed with a special rubber coating applied to them. With a small drive train assembled, it’s off to the races for this tiny prototype.

While the small car doesn’t have steering and only goes at a constant speed, the proof of concept that these tiny electric engines actually work is a welcomed addition to [Emiel]’s collection of videos on these curious engines. Of course they’re not as efficient as driving the wheels directly with an electric motor, but we all know there’s no fun in that. If you haven’t seen his most intricate build, the V8 is certainly worth checking out, and also shows off the timing circuitry he repurposed for this car.

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Feel What The Temperature Is Like Outside Without Leaving Your Bed

Your smartphone might be able to tell you what the weather is like outside, but you’d have to go outside yourself to really feel it. To do this from the comfort of your own bed, [Sagarrabanana] built a clock that lets you really feel the temperature. Video below with English subtitles.

It is basically a box with a solenoid inside to knock out the time, and a Peltier plate on top. Give the box two knocks, which are detected by a piezo element,  and it will tell you the current time down to 15 minute increments in “bell tower” format. Give it three knocks, and the ESP8266 will fetch the ambient outside temperature from a cloud service and cool or heat the Peltier element to that temperature, using a H-bridge motor driver module. The code and design files are available on GitHub if you want to build your own.

All the components are housed inside an attractive 3D printed box with a machined wood top. Although we think this is a very interesting idea, we can’t help but suspect that it might be counterproductive for getting you out of bed on those cold winter mornings.

While alarm clocks are falling out of favor, they are still a popular build for hackers. We’ve covered one that looks like it came from a fallout shelter, and another with a very cool looking VFD display. Continue reading “Feel What The Temperature Is Like Outside Without Leaving Your Bed”

Build An ESP32 Stock Ticker To Watch Your GME Gains

Meme investing is all the rage these days, and what better way to get in on the loss fun than with your very own old-timey mechanical stock ticker? Unfortunately, they’re about as expensive and rare as you might expect for a piece of Victorian-era electronics. Lucky for us, [secretbatcave] has shown that you can put together a functional look-alike that costs about as much as a GameStop (GME) share was worth before it started heading to the Moon.

This might seem like an ambitious project, but in actuality the machine only has a few moving parts. There’s a stepper motor to feed the paper, another to spin an inked embossing wheel, and a couple of solenoids attached to a pusher plate. Rather than trying to move the heavy wheel, the pusher plate smashes the paper up into it. The fact that this produces a satisfying “clack” sound as each character is printed is just an added bonus.

Extending the base to hold the solenoids.

To sell the look, [secretbatcave] put the whole mechanism inside a tall glass dome from IKEA. The matching wooden base was extended so the pusher plate solenoids could fit inside, after which it was dunked in ink and sprayed with a gloss sealer to give it that shiny black finish people seemed to love in the 1900s. With the addition of an engraved brass nameplate, it looks like the machine fell out of a time warp.

In terms of electronics, there’s an ESP32, a pair of stepper motor controllers, and a relay for the solenoids. As of right now it all lives in a rather utilitarian box that’s tethered to the ticker, but we’re sure the lot could get tucked under the base with the help of a custom PCB should you be so inclined.

With an ESP32 at the helm, the ticker could easily be configured to print out whatever data it receives over the network or picks up from MQTT. With hardware like this and a pair of Diamond Hands, those tendies are as good as yours.

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Toggle Switch Puzzle Boggles The Mind, Opens The Box

We all have too much stock of one component or another. Maybe you have more audio pots than you know what to do with, or maybe it’s zener diodes. For [technologyguy], that thing is a pile of toggle switches.  Fortunately he’s always wanted to build a locking box with a binary code that’s laid out in switches — as in, find the right code, and a solenoid unlatches the box. This lovely parts bin special only responds to two combinations out of a possible 4,000+, so anyone who tries to open it should probably block out the afternoon.

Inside you’ll find two 9 V batteries, a home-brew metal latch, a solenoid, and the undersides of four DPDT and eight SPDT toggle switches. If you just picked this thing up and had no idea what was going on, you’d be so screwed as to what to do first. The box needs power, so you’d have to figure out which switch is which. But it’s so much harder than that, because the bottom left switch selects between the two paths that result in an unlocked book-box.

The next two toggles in from the left are on/off selectors for code A and code B, so not only do you have to have the right path chosen, you have to power it, too. The only progress indicators are the LEDs — there’s one for main power, and the other lets you know that the box is unlatched. What a fun conversation piece for the coffee table Zoom-viewable area!

Want to do something far less useful with your throng of toggles? How about a complicated useless machine?

BEAM-Powered, Ball-Flinging Beam Has Us Beaming

We have a soft spot for BEAM projects, because we love to see the Sun do fun things when aided by large capacitors. [NanoRobotGeek]’s marble machine is an extraordinary example — once sufficiently charged, the two 4700 μF capacitors dump power into a home-brew solenoid, which catapults the ball bearing into action toward the precipice of two tracks.

[NanoRobotGeek] started with the freely-available Suneater solar circuit. It’s a staple of BEAM robotics, slightly modified to fit the needs of this particular project. First up was verifying that the lever (or beam, if you will) principle would work at all, and [NanoRobotGeek] just built it up from there in admirable detail. The fact that it alternates between the swirly track and the zigzag track is entrancing.

There are several disciplines at play here, and we think it’s beautifully made all around, especially since this was [NanoRobotGeek]’s first foray into track bending. We love the way it flings the ball so crisply, and the track-changing lever is pretty darn satisfying, too. You can check it out in action in the video after the break.

Although this was [NanoRobotGeek]’s maiden marble track, it’s not their first circuit sculpture — check out this flapping, BEAM-powered dragonfly.

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A Pair Of Steppers Are Put To Work In This Automatic Instrument Pickup Winder

For something that’s basically a coil of wire around some magnetic pole pieces, an electric guitar pickup is a complicated bit of tech. So much about the tone of the instrument is dictated by how the pickup is wound that controlling the winding process is something best accomplished with a machine. This automatic pickup winder isn’t exactly a high-end machine, but it’s enough for the job at hand, and has some interesting possibilities for refinements.

First off, as [The Mixed Signal] points out, his pickups aren’t intended for use on a guitar. As we’ve seen before, the musical projects he has tackled are somewhat offbeat, and this single-pole pickup is destined for another unusual instrument. That’s not to say a guitar pickup couldn’t be wound on this machine, of course, as could inductors, solenoids, or Tesla coils. The running gear is built around two NEMA-17 stepper motors, one for the coil spindle and one for the winding carriage. The carriage runs on a short Acme lead screw and linear bearings, moving back and forth to wind the coil more or less evenly. An Arduino topped with a CNC shield runs the show, allowing for walk-away coil winding.

We do notice that the coil wire seems to bunch up at the ends of the coil form. We wonder if that could be cured by speeding up the carriage motor as it nears the end of the spool to spread the wire spacing out a bit. The nice thing about builds like these is the ease with which changes can be made — at the end of the day, it’s just code.

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