Arduino Hacks

3044 Articles

Music Box Paper-Punching Machine Settles The Score

November 15, 2019 by 11 Comments

As soon as [pashiran] laid eyes on his first hand-cranked music box, he knew he was in love. Then, he started punching the holes for his first ditty. As the repetitive stress of punching heated up his arm, his love cooled a bit. Annealed by the ups and downs of this experience, he decided to design a machine that can punch the holes automatically.

Soon, [pashiran] found his people — a community of music boxers that transform MIDI files to DXF format, which creates coordinates for CAD software. In [pashiran]’s music puncher, an Arduino MEGA takes a DXF file and bubble-sorts the jumble of x-coordinates. The MEGA conducts a trio of two stepper motors and DC motor. One stepper pushes the paper through on the x-axis, and the other moves the puncher head back and forth across the paper scroll as the y-axis. The DC motor moves the punch up and down.

Now, paired with [Martin] of [Wintergatan]’s method for chaining music box paper together, [pashiran] can write a prog-rock-length opus without fear of repetitive stress injury. And since he’s published the STL and INO files, now you can, too. Watch it punch and play 250 notes worth of “See My Vest” “Be Our Guest” after the break.

There’s more than one way to avoid manually punching all those holes. When [Wintergatan] was wrestling this problem, he inspired the hacker community to create a MIDI-to-laser-cut-stencil solution.

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Finally Your Air Drumming Has An Outlet

November 15, 2019 by 8 Comments

Two engineering students are hard at work on this air drum which they hope will help disabled people and people in nursing homes. Though, we think it just looks fun!

Each board is its own module consisting of the electronics and 3D printed cases. The modules each contain an arduino mini, IR sensor, and LEDs. They share power, audio, and communicate with an i2c bus. Two modules are special, one holds the power system and the other a Raspberry Pi. The units can be put together in different configurations. Finally, they are capped with speaker units.

The demo shown in the video, which you can see after the break, looks fun. The response time is pretty fast and it looks like you can measure all sorts of parameters. This can then be translated into different velocities, pitches, and instruments. It’s somewhere between a theremin and a drum kit, very cool.

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This Arduino Keeps Its Eyes On You

November 13, 2019 by 5 Comments

[Will] wanted to build some animatronic eyes that didn’t require high-precision 3D printing. He wound up with a forgiving design that uses an Arduino and six servo motors. You can see the video of the eyes moving around in the video below.

The bill of materials is pretty simple and features an Arduino, a driver board, and a joystick. The 3D printing parts are easy to print with no supports, and will work with PLA. Other than opening up holes there wasn’t much post-processing required, though he did sand the actual eyeballs which sounds painful.

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Simulate City Blocks With Circuit Blocks In A LEGO Box

November 12, 2019 by 4 Comments

Have you ever looked around your city’s layout and thought you could do better? Maybe you’ve always wanted to see how she’d run on nuclear or wind power, or just play around with civic amenities and see how your choices affect the citizens.

[Robbe Nagel] made this physical-digital simulator for a Creative Programming class within an industrial design program. We don’t have all the details, but as [Robbe] explains in the video after the break, each block has a resistor on the bottom, and each cubbyhole has a pair of contacts ready to mate with it. An Arduino nestled safely in the LEGO bunker below reads the different resistance values to determine what block was placed where.

[Robbe] wrote a program that evaluates various layouts and provides statistics for things like population, overall health, education level, pollution, etc. As you can see after the break, these values change as soon as blocks are added or removed. Part of what makes this simulator so cool is that it could be used for serious purposes, or it could be totally gamified.

It’s no secret that we like LEGO, especially as an enclosure material. Dress it up or dress it down, just don’t leave any pieces on the floor.

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Printed Arduino Turntable Takes Objects For A Spin

November 12, 2019 by 5 Comments

Have you built a 3D scanner yet? There’s more than one way to model those curves and planes, but the easiest may be photogrammetry — that’s the one where you take a bunch of pictures and stitch them into a 3D model. If you build a scanner like [Brian Brocken]’s that does almost everything automatically, you might consider starting a scan-and-print side hustle.

This little machine spins objects 360° and triggers a Bluetooth remote tethered to an iPhone. In automatic mode, it capture anywhere from 2-200 pictures. There’s a mode for cinematic shots that shoots video of the object slowly spinning around, which makes anything look at least 35% more awesome. A third mode offers manual control of the turntable’s position and speed.

An Arduino UNO controls a stepper that moves the turntable via 3D printed-in-place bearing assembly. This project is a (vast) improvement over [Brian]’s hand-cranked version that we looked at over the summer, though both are works of art in their own right.

Our favorite part aside from the bearing is the picture-taking process itself. [Brian] couldn’t get the iPhone to play nice with HC-05 or -06 modules, so he’s got the horn of 9g servo tapping the shutter button on a Bluetooth remote. This beautiful beast is wide open, so fire up that printer. You can watch the design and build process of the turntable after the break.

Want to scan some really tiny things? Make a motorized microscope from movie machines.

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New Part Day: Alexa Connect Kit Now Available For Sale

November 11, 2019 by 8 Comments

People who were subscribed to updates on the Alexa Connect Kit (ACK) would recently have received an email informing that this kit is now available for sale. Last time we covered the ACK was back in September of 2018, the ‘release’ moniker meant ‘preview’ and there wasn’t any hardware one could actually purchase.

Over a year a later it seems that we can now finally get our grubby mitts on this kit that should enable us to make any of our projects Alexa-enabled. What this basically seems to mean is that one can spend close to 200 US dollars on an Arduino Zero and an Arduino shield-mounted WM-BN-MT-52 module from USI (though not listed on their site, but similar to the WM-BN-BM-22?) that integrates a 192 MHz Cortex-M MCU and a WiFi/Bluetooth module, as summarized on the Amazon Developer page for the ACK.

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Accessibility Apps Get Help From Bluetooth Buttons

November 10, 2019 by 4 Comments

Ever hear of Microsoft Soundscape? We hadn’t, either. But apparently it and similar apps like Blindsquare provide people with vision problems context about their surroundings. The app is made to run in the background of the user’s mobile device and respond to media controls, but if you are navigating around with a cane, getting to media controls on a phone or even a headset might not be very convenient. [Jazzang] set out to build buttons that could control apps like this that could be integrated with a cane or otherwise located in a convenient location.

There are four buttons of interest. Play/pause, Next, Back, and Home. There’s also a mute button and an additional button you can use with the phone’s accessibility settings. Each button has a special function for Soundscape. For example, Next will describe the point of interest in front of you. Soundscape runs on an iPhone so Bluetooth is the obvious choice for creating the buttons.

To simplify things, the project uses an Adafruit Feather nRF52 Bluefruit board. Given that it’s Arduino compatible and provides a Bluetooth Human Interface Device (HID) out of the box, there’s almost nothing else to do for the hardware but wire up the switches and some pull up resistors. That would make the circuit easy to stick almost anywhere.

Software-wise, things aren’t too hard either. The library provides all the Bluetooth HID device trappings you need, and once that’s set up, it is pretty simple to send keys to the phone. This is a great example of how simple so many tasks have become due to the availability of abstractions that handle all of the details. Since a Bluetooth HID device is just a keyboard, you can probably think of many other uses for this setup with just small changes in the software.

We covered the Bluefruit back when it first appeared. We don’t know about mounting this to a cane, but we do remember something similar attached to a sword.

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