Arduino Hacks

3048 Articles

Laser Tachometer Knows How Fast You Were Spinning Back There

February 12, 2020 by 25 Comments

Does your drill go as fast as the manufacturer says it will? Well, you’d need a tachometer to figure that out. They’re not that expensive to buy, but as [Elite Worm] shows, they’re not that expensive to make, either — about $10 total if you get your parts from the right places. Lucky for you, he has links to everything.

Really, the links are just the tip of the iceberg here as far as the gifts that [Elite Worm] bestows upon those who choose to undertake this project. The build video (after the break, as usual; our favor to you) is fantastic, and would be perfect for a beginner because of the entrancing speed at which he builds it. The video is straight up relaxing to watch, whether you want to build one or not.

It’s a fairly simple circuit — just push the momentary switch, and the laser diode and sensor pair count the revolutions over one second. The Arduino Nano multiplies this number by 60 and displays the RPM on the OLED screen. What we absolutely love about this build is the care that taken in designing the case. There’s a designated spot for each component, and the ones without their own special holder are kept in place with printed crossbar pieces. [Elite Worm] says this has a higher refresh rate than his store-bought tacho, and we say it looks way cooler, too.

Still don’t want to make one yourself? Well, okay. Before you buy one, try using your phone to calculate RPM.

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Building A Sound Activated Shop Fan With Arduino

February 10, 2020 by 12 Comments

Whether you’re using a soldering iron or a table saw, ventilation in the shop is important. Which is why [Atomic Dairy] built a monster air cleaner called the Fanboy that looks like it should be mounted under the wing of an F-15. Realizing a simple switch on the wall wouldn’t do this potent air mover justice, they decided to build a sound activated controller for it.

It’s certainly an elegant idea. The sound created once they kick on their woodworking tools would be difficult to miss by even the most rudimentary of sound-detection hardware. At the most basic level, all they needed was a way for an Arduino to throw a relay once the noise level in the room reached a specific threshold.

Of course it ended up getting a bit more complicated than that, as tends to happen with these kinds of projects. For one, the sound doesn’t directly control the solid state relay used in the fan controller. When the microphone equipped Arduino detects enough noise, it will start a timer that keeps the fan running for two hours. If the tool keeps running, then more time gets added to the clock. This ensures that the air in the room is well circulated even after the cutting and sanding is done.

[Atomic Dairy] also added a few additional features so they could have more direct control over the fan. There’s a button to manually add more time to the clock, and another button to shut it down. There’s even support for a little wireless remote control, so the fan can be operated without having to walk over to the control panel.

We’ve seen some impressive air circulation and dust collection systems over the years, but finding a way to elegantly switch them on and off has always been a problem given the wide array of tools that could be in use at any given time. Sound activation isn’t a perfect solution, but it’s certainly one we’d consider for our own shop.

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3D Printing For Wire Paths Yields An Arduboy Minus The PCB

February 8, 2020 by 23 Comments

What is part way between a printed circuit board and a rats-nest of point-to-point wiring? We’re not sure, but this is it. [Johan von Konow] has come up with an inspired solution, 3D printing an Arduboy case with channels ready-made for all the wires. The effect with his 3DPCBoy is of a PCB without the PCB, and allows the console to be made very quickly and cheaply.

The Arduboy — which we originally looked at back in 2014 — is a handheld gaming console in a somewhat Gameboy-like form factor. Normally a credit-card sized PCB hosts all the components, including a microcontroller, display, and buttons. Each has a predictable footprint and placement so they can simply be wired together with hookup wire, if you don’t mind a messy result.

Here the print itself has all the holes ready-created for the components, and the path of the wires has a resemblance to the sweeping traces of older hand-laid PCBs. The result is very effective way to take common components — and Arduino pro micro board for the uC, an OLED breakout board, and some buttons — and combine them into a robust package. This technique of using 3D prints as a combination of enclosure and substrate for components and wiring has an application far beyond handheld gaming. We look forward to seeing more like it.

[Via the Arduboy community forum, thanks Kevin Bates for the tip.]

A Laser Drawing Machine For Flashes Of Creativity

February 7, 2020 by 6 Comments

Ahh, midterms. Some students blow off steam between study sessions by playing video games or just zoning out. While those kids were all distracted, [Justinwong777] and his buddy [Brett] found a bunch of scrap wood and built this laser drawing machine in their school’s makerspace. You operate it as you might an Etch-a-Sketch, except your drawings are as fleeting as sparkler art on the 4th of July, if they made Tron-colored sparklers.

Though you work it like an Etch-a-Sketch, the business end operates like a laser cutter. Inside that plywood enclosure is an Arduino Uno and a pair of motors. These motors turn a series of custom gears, which move a small mirror angled at 45° in the xy-plane.  There’s a 30mW laser mounted parallel with the base, pointed at the mirror, and it reflects the beam toward a canvas panel coated with phosphorescent paint. We dig the printed ergonomic case for the joystick, which gives control of both x and y. Put on some eye protection and check it out after the break.

If you want to draw with lasers, but aren’t much of an artist, do something unexpected: build a laser turret not to kill, but to draw the weather on the wall.

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Tool Writes Your PWM Code For You

February 6, 2020 by 40 Comments

The good thing about computers is they do your work for you, right? If you are a programmer, that doesn’t always seem to be a true statement. [Runtimemicro] has the answer, at least if you are writing PWM code for the Arduino. Their free application lets you set a few parameters, visually see the results, and then generates code for you. You can see a video of the tool in operation, below.

According to their site, the tool works for timers 1 through 5 on an Arduino Nano, Uno, or Mega2560. The app appears to work on Windows, but it doesn’t look like it would have any trouble running under Wine on other platforms.

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Arduino Handheld Game System Gets A Grip

February 6, 2020 by 7 Comments

With little more than an Arduino, an OLED display, and some buttons, it’s easy to build your own faux-retro game system. There’s even a growing library of titles out there that target this specific combination of hardware, thanks in no small part to the Arduboy project. But unless you’re content to play Circuit Dude on a breadboard, at some point you’ll probably want to wrap the build up in a more convenient form.

Like many that came before it, the OLED handheld created by [Alex Zidros] takes inspiration from a Nintendo product; but it’s not the Game Boy. Instead, his design is based on a 3D printed grip for the Switch Joy-Cons that he found on Thingiverse. After tacking on a holder for the PCB, he had the makings of a rather unique system.

We especially like the offset SSD1306 OLED display. Not because we think a game system with an asymmetrical layout is a particularly sound design decision, but because it gives the whole build a rather cyberpunk feel. When combined with the exposed electronics, the whole system looks like it could have been cobbled together from a futuristic dumpster. Which is high praise, as far as we’re concerned.

Opposite the display is a LiPo pouch battery that [Alex] says was liberated from a portable speaker, and down below is an Adafruit Feather 328P. There are two tactile switches mounted to the front of the Feather, and in something of a departure from these sort of builds, there are two more on the shoulders of the 3D printed case. Everything is held together with nothing more exotic than a scrap of perfboard, making it easy for anyone who might want to build their own version.

If you prefer your Arduino and OLED gaming to come in a slightly more familiar form factor, the build that was done inside of a Dreamcast Visual Memory Unit (VMU) has always been a favorite around these parts.

Micro Macro Keyboard Makes A Major Difference

February 5, 2020 by 10 Comments

Media keyboards are nice in theory. But in practice they never have all the keys you want, and they almost always have a few you don’t. Sure, you could maybe reassign the ones you don’t use, but then the caps are wrong, and it’s a whole thing. So really, the only winning move is to make a micro macro keyboard as [littleSilvr] did to make all your shortcuts one-button accessible.

This lovely input has an Arduino Pro Micro for a brain, and Gateron browns for brawn. That knob there is a rotary encoder, not a potentiometer, because endless volume knob twiddling is just so much nicer. In case you’re wondering, those shortcuts open Fusion 360 and Cura, but we’re still not sure what the hyphen does.

Can we talk about those keycaps, though? [littleSilvr] used [Make Anything]’s process of of printing in multi-color with a single extruder. The technique involves building a vector for each color, each of which gets its own STL file. Then you add retraction as you go up through the layers, slow the print speed, change filament colors while the nozzle and bed are still warm, and voila, a vibrant canvas of colors.

If you don’t have a printer and you don’t mind a bit of compromise on the number of inputs, try basing your build on an existing input, like an old rotary telephone dialer.

Via r/duino