LED Ping Pong Ball Display

Looking to build a large LED display project  David Vogt came up with this magnificent LED Ping Pong Ball display.

Because this project was for high school students it needed to be easy to assemble without advanced electronics skills.  It also needed to be budget friendly.

Early in the design it was decided to use ping pong balls to diffuse the LEDs.  This set the spacing of the LEDs to the 38 mm diameter of the ball.  This created a new challenge as the convenient LED strips don’t match up to this desired spacing.  Cutting up the LED strips into individual parts and rewiring them was not desired.  David came up with a 3D printed matrix frame to mount the ping pong balls and would easily hold individual PCB mounted LEDs. The custom matrix is modular and allows for easy construction.

The individual ping pong ball holders mount into a larger matrix to hold them together and make it easier to wire up the LEDs.

The task of cutting and stripping wire for the 1800 solder joints was not one that David relished.  He got creative and rigged up a jig using card stock to hold the wire and used a laser cuter to strategically strip insulation off the wire. The wire was then ready to be placed in the holder and be soldered up.

The display is controlled with a combination of a Raspberry Pi to generate the images and a Teensy 3.2 to send the data to the display.

The end result is a massive LED display that is fun to watch.

Code for the project is available on GitHub

The STL 3D print files are available on the project page

This project was also covered by Hackaday and Hackster.io


IBM Model M Keyboard Restoration

Thea “Stargirl” Flowers restored this non-working IBM Model M keyboard by creating all new electronics.

The electronics are replaced by this custom circuit board.

On Twitter, she explains “Unless the controller board is fried (like this one was) I recommend using an external converter over doing this, as they are nice vintage electronics and should be preserved if possible.” and “If it’s mint and functional I’d go for a ps/2 to USB adapter and leave the guts intact. This one came to me non-functional so I had to replace the membrane and control board.

But replacing all the electronics did allow for small upgrades, such as replacing 3 LEDs.

A second PCB with 3 addressable LEDs allows them to be any color.

While a detailed blog article was never written, she did share all the source code and PCB files on GitHub, of which she explains “With two months of free time you too can have a USB model M! (Or you can just buy a ps/2 to USB converter)“.

Propane Powered Lightsaber

HACKSMITH Industries have produced the world’s first retractable plasma-based lightsaber.

The lightsaber is controlled by a Teensy 4.0 and powered by LPG (compressed liquid propane gas) mixed with oxygen. The resulting plasma burns at 4000 degrees Fahrenheit and is able to cut through titanium. This powerful combination was made using a bespoke circuit design that you can find and inspect on the DigiKey site.

Hacksmith Industries has an active YouTube channel where you can find more of their ambitious builds.


High Resolution Budget Polarimeter

A team of research scientists including John de Mello, A.J. Harvie, and T.W. Phillips have developed a low-cost, high-accuracy polarimeter that uses a Teensy 3.6.

In the study released in Scientific Reports, the team reveals the inspiration for the project as well as their DIY approach to creating the plans for a low cost but high resolution open-hardware instrument suitable for scientific research.

Polarimeters are typically very expensive but extremely useful devices. They are used to measure the angle of rotation caused by passing polarized light through an optically active substance and can actually be used to distinguish chemicals as many chemicals have a unique rotational-angular signature. While the first polarimeters developed in the 60s needed to be controlled manually, modern polarimeters are motorized with integrated photo detectors and can be used to take automatic measurements. A single device, however, can cost upwards of $14,000.

In a tweet, nanomaterials specialist John de Mello stated the team wanted to create a device which could produce the same “high-end specs at a bargain-basement price.” For inspiration, the team loosely based their model on a design by the All-Russia Scientific Research Institute of Optophysical Measurements.


Nintendo Power Glove Modification

Glytch, an electronics hobbyist, has produced a Nintendo Power Glove modification that grants the device an impressive amount of control.

The Nintendo Power Glove is perhaps one of the most iconic and nostalgic pieces of wearable gaming technology. Originally released in 1989, the glove wasn’t as successful in its functionality as it was in its marketing. Featured in the film The Wizard, the glove was marketed as a virtual reality controller capable of granting players “free-flowing instant response” but many users found the controls difficult to use as the glove only provided tracking on one axis (roll) using ultrasonic sensors and used conductive ink to track the fingers leading to low resolution hand tracking.

Glytch’s mod gives the glove the power to control robots weighing up to 200 lbs. More specifically, a t-shirt cannon! In a post made to Twitter, Glytch shows off the project in progress controlling a small rover.

The project arrives just in time for the Power Glove’s 30th anniversary. In a video Glytch uploaded to his Youtube Channel he talks about how amusing it is to hack a piece of technology that’s seven years older than he is. The project uses a Teensy LC, two NRF modules for transmitting data between the glove and the robot, an IMU in place of the original ultrasonic sensors for hand tracking, flex sensors for finger tracking, and custom PCBs developed by Nolan Moore who has also shared his own mod which the project is based on at Hackster.io.

Glytch has previously worked on lots of awesome projects, including hacking your laptop’s webcam and modifying your 3D printer to run on USB-C.

The Dwelling – Electronic Art at Burning Man

The Dwelling is an electronic art installation designed for Burning Man 2019. The Dwelling is a stranded alien spaceship, pulsing and glowing with light at night.

For hardware hackers with an artistic side, the Burning Man playa is known as a great place to find inspiration and experiment with electronic art. The Dwelling was built by a group of hackers and artists including Philip Levis, Jasmine Brackett and Yariv Keinan.

If you want to see more pictures of the finished installation or of the artwork at various stages during its construction, the creators of the Dwelling project have published extensive build logs over on their blog. They have also wrote a super informative post about the external electronics with a detailed breakdown of the lighting set up, power requirements and their plans to drive it all with the Teensy 3.6.

MIDI DIN to USB Converter

What living electronic musician hasn’t encountered the need for a MIDI to USB converter at some point in their career? When forum user XFer experienced this need, they did what any clever hacker would do: DIY their own converter.

XFer used a Teensy 3.6 and the MIDI Library guide on the PJRC website to set up the hardware and software. They also added a portable battery bank to provide power for both adapter and keyboard that lasts for up to three hours as well as connecting a pair of LEDs to indicate the status of the MIDI connection. XFer has included the source code for the project in their forum post along with some awesome photos of the adapter in its 3D printed case with inputs for all the cables.