instructable

21 Articles

A piano is pictured with two hands playing different notes, G outlined in orange and C outlined in blue.

AI Piano Teacher To Criticize Your Every Move

June 22, 2025 by 15 Comments

Learning new instruments is never a simple task on your own; nothing can beat the instant feedback of a teacher. In our new age of AI, why not have an AI companion complain when you’re off note? This is exactly what [Ada López] put together with their AI-Powered Piano Trainer.

The basics of the piano rely on rather simple boolean actions, either you press a key or not. Obviously, this sets up the piano for many fun projects, such as creative doorbells or helpful AI models. [Ada López] started their AI model with a custom dataset with images of playing specific notes on the piano. These images then get fed into Roboflow and trained using the YOLOv8 model.

Using the piano training has the model run on a laptop and only has a Raspberry Pi for video, and gives instant feedback to the pianist due to the demands of the model. Placing the Pi and an LCD screen for feedback into a simple enclosure allows the easy viewing of how good an AI model thinks you play piano. [Ada López] demos their device by playing Twinkle Twinkle Little Star but there is no reason why other songs couldn’t be added!

While there are simpler piano trainers out there relying on audio cues, this project presents a great opportunity for a fun project for anyone else wanting to take up the baton. If you want to get a little more from having to do less in the physical space, then this invisible piano is perfect for you!

PIR Sensor In A Jar Helps You Keep Your Concentration

December 24, 2020 by 16 Comments

While there are loads of impressive and complex projects here on Hackaday, sometimes it’s the simple ones that really speak to us. In this case we were presented with [Isabell Park]’s easy-to-follow instructable on how to build an anti-procrastination device.

On the hardware side there are no surprises, it consists of a PIR sensor connected to a NodeMCU microcontroller. It checks for a signal from the sensor, and if it’s triggered, it sends a command through the Adafruit IO libraries to IFTTT. On its own it could make for a decent movement alarm, but the part that makes the project interesting is how it’s applied to become a device to help with procrastination instead.

First, you put your phone in a jar along with the electronics and close it. Then, with everything configured, the circuit is powered on and stays vigilant for any movement inside the jar. Should you try to take your phone out of it for a quick social media break (which, if you’re like us, can turn into a few hours), IFTTT will be alerted and run through whatever script you have in place. In [Isabell]’s case, she suggests sending an SMS to a trusted contact to keep you in check.

If you’re looking to keep track of how much time you’ve spent procrastinating, have we got a clock for you. But if you’re looking for more projects involving PIR sensors, we have one that alerts you when your cat is back home. Meanwhile, check out this one in action after the break. Continue reading “PIR Sensor In A Jar Helps You Keep Your Concentration” →

A 3D Printed Marble Clock

September 12, 2018 by 11 Comments

There are clocks with pendulums, gears, and circuits. How about one with marbles? Initially designed in the ’70s, rolling ball clocks came in many designs and materials, but this is the future, so [gocivici] has created an Instructable to show you how you can 3D print and build your own.

Three rows of marbles keep track of the time, one for one hour intervals, one for five-minute intervals and a third for one minute intervals. It makes reading the time a bit more difficult than a pair of hands, but more fun. The clock uses the weight of the marbles to know when a row needs resetting. When the fifth marble drops onto the minute row, its weight causes the row to tilt, sending all but one marble down to the bottom of the machine. The marble that caused the tilting is sent down to the row underneath, perhaps causing a cascade of marbles down to the bottom.

There is something quite satisfying about seeing the marbles moving around in [gocivici]’s mechanical marble clock. Sure, it’s probably too loud for the nightstand, but it keeps time and looks great. In this build a stepper motor drives the main wheel which acts as an elevator, grabbing a marble from the bottom and raising it to the top to tumble down and find its position among the rows.

Of course, at Hackaday we love clocks so there have been many clock builds showcased here; all you need do is a quick search for “clock” to find some incredible designs and builds. We’ve also featured similar marble clocks.

via BoingBoing

Continue reading “A 3D Printed Marble Clock” →

Fresh-Baked Plastic Tiles For All!

December 30, 2017 by 46 Comments

Recycling aims to better the planet, but — taken into the hands of the individual — it can be a boon for one’s home by trading trash for building materials. [fokkejongerden], a student at the [Delft University of Technology] in the Netherlands, proposes one solution for all the plastic that passes through one’s dwelling by turning HDPE into tiles.

Collecting several HDPE containers — widely used and easy enough to process at home — [fokkejongerden] cleaned them thoroughly of their previous contents, and then mulched them with a food processor. An aluminium mold of the tile was  then welded together making sure the sides were taller than the height of the tile. A second part was fabricated as a top piece to compress the tile into shape.

After preheating an oven to no hotter than 200 degrees Celsius, they lined the mold with parchment paper and baked the tile until shiny(90-120 minutes). The top piece was weighed down (clamping works too), compressing the tile until it cooled. A heat gun or a clothes iron did the trick to smooth out any rough edges.

Not only does [fokkejongerden]’s tiles give the recycler plenty of artistic freedom for creating their own mosaic floor, the real gem is the adaptable plastic recycling process for home use. For another method, check out this recycled, recycling factory that turns bottles in to rope and more! There’s even the potential for fueling your 3D printer.

[Via Instructables]

Bringing A Christmas Lights Show Inside

December 21, 2017 by 15 Comments

Instructables user [Osprey22] has been building towards this Christmas for years. Why? This year, he has brought an impressive musical Christmas light display inside, and at a fraction of the cost too!

An box at the tree’s base hides the power supply and the controller boards — a Raspberry Pi and a SanDevices e682 Pixel controller for the 400 WS2811 RGB LEDs — with an added router to connect them to the main network. The Pi is running Falcon Pi Player and a projector somewhere in the region of $100 complements the light show.

As far as mapping out the LEDs, Xlights is the program of choice, locating the LEDs in space with the help of a cell phone video recording. [Osprey22] had to write a quick program in C to fix the LED overlaps in the grid. (A spreadsheet would work just as well, here). Oh, and the gifts at the bottom of the tree double as a projector screen!

Continue reading “Bringing A Christmas Lights Show Inside” →

Edge-lit Pendants Show Two Layers Are Better Than One

July 28, 2017 by 7 Comments

Engraved acrylic lights up nicely with LED lighting. Simply engrave clear acrylic with a laser engraver, then edge-light the acrylic and watch the engraving light up. This badge made by [Solarbotics] shows how they used this principle when creating some pendants for an event that performed particularly well in the dark.

The pendants they created have two engraved acrylic panels each, and that’s about it. Two LEDs and a CR2032 battery nestle into pre-cut holes, and the engraved sides are placed face-to-face, so the outer surfaces of the pendant are smooth. By using some color-cycling RGB LEDs on one panel and blue LEDs on the other panel, the effect is that of an edge-lit outer design with a central element that slowly changes color separately from the rest of the pendant.

The design stacks the LED leads and coin cells in such a way that a simple wrap of tape not only secures things physically, but also takes care of making a good electrical connection. No soldering or connectors of any kind required. [Solarbotics] found that CR2032 cells would last anywhere between a couple of days to a week, depending on the supplier.

This design is great for using a minimum of materials, but if that’s not a priority it’s possible to go much further with the concept. Multiple layers of edge-lit acrylic were used to make numeric 0-9 display modules as well as a full-color image.

 

Wood And Rubber Band Pinball

February 12, 2017 by 9 Comments

As pinball has evolved, it has gone from a simple gravity based game to an electromechanical one.  As the 20th century came to a close, pinball games added digital elements as well, matrix displays replaced electromechanical scoreboards, and LEDs replaced incandescent bulbs. While the game got more creative as new technologies became available, the basics of the pinball never changed – keep the ball alive using your skill with the flippers (and the occasional nudge.) [Garagem Fab Lab] has taken the basics of the pinball machine and, with some wood and elastic bands, has created a very nice desktop pinball machine.

The plans for the game require getting the wood cut by a CNC mill, but they could probably be easily created using a jigsaw. Instead of electrical buttons and solenoids, pieces of wood push the flippers out and elastics reset them when released. The bumpers, too, are simple dowels with rubber bands wrapped around them. The launching mechanism is a bit of bungee cord tied onto a piece of wood and used like a flipper to speed the ball into the play area.

The build is a throwback to the earliest pinball machines. Sure, there’s no reaction from the bumpers when they’re hit, they’re just passive, but the game looks fun. It would be a great base to add in some sensors, a microcontroller, and a display to keep track of scores if one was so inclined. Other DIY pinball machines we’ve seen are this pinball game built with Meccano and lasers, as well as this completely 3D-printed machine.