Author: Zoe Skyforest

3823 Articles

3D Printing An Old-School Coherer

July 13, 2019 by 29 Comments

Coherers were devices used in some of the very earliest radio experiments in the 19th century. Consisting of a tube filled with metal filings with an electrode at each end, the coherer would begin to conduct when in the presence of radio frequency energy. Physically tapping the device would then loosen the filings again, and the device was once again ready to detect incoming signals. [hombremagnetico] has designed a basic 3D printed version of the device, and has been experimenting with it at home.

It’s a remarkably simple build, with the 3D printed components being a series of three brackets that combine to hold a small piece of plastic tube. This tube is filled with iron filings, and electrodes are inserted from either end. Super glue is used to seal the tube, and the coherer is complete.

The coherer can easily be tested by measuring the resistance between the two electrodes, and firing a piezo igniter near the tube. When the piezo igniter sparks, the coherer rapidly becomes conductive, and can be restored to a non-conductive state, or de-cohered, by tapping the tube.

Coherers and spark-gap sets are fun to experiment with, but be sure you have the proper approvals first. Video after the break.

Continue reading “3D Printing An Old-School Coherer” →

Simple Simon Says Looks Sharp

July 12, 2019 by 4 Comments

Simon was a popular toy, launching at the very end of the 1970s, and cribbed from earlier work by Atari with their game Touch Me. The gameplay is simple, and while we suspect it won’t last quite as long as the several thousand years we’ve so far had chess, it’s still around today. [DIY Machines] decided to bust out the 3D printer and whip up their own version.

Simon has long served as a great test project to get to grips with various maker skills, and this build is no exception. An Arduino Nano runs the show, and gets an OLED display to display the current level. Large glowing arcade buttons serve as the control, with their lights flashed as per the original game. Sound is courtesy of a simple buzzer.

It’s a build that doesn’t do anything wild, but presents very well. This is down to the smoothly finished and nicely designed case, as well as the choice of quality human interface components. Everyone loves mashing arcade buttons, and that’s what they’re built for – so they’re always a safe choice.

We’ve seen a lot of straight-down-the-lines Simon projects, but this DDR-ified version is a fun twist on the standard form. Video after the break.

Continue reading “Simple Simon Says Looks Sharp” →

Photochromic Screen Makes For An Interesting Clock

July 12, 2019 by 4 Comments

The clock project will always be a hacker staple, giving the builder a great way to build something useful and express their individual flair. [Mosivers] was undertaking a build of their own and decided to go for a twist, creating a timepiece with a photochromic display.

The clock uses an Arduino Nano to run the show, hooked up to a 4-digit, 7-segment display that is custom built on protoboard. By using ultraviolet LEDs and placing them behind a reactive screen, it’s possible to create a unique display. The clock can be used with two different screens: a photochromic display created with UV-reactive PLA filament that turns purple when excited by UV light, and a glow-in-the-dark screen for night use.

It’s a fun twist on a simple clock design, and the purple-on-white digits are sure to raise some eyebrows among curious onlookers. Photochromic materials are fun to play with, and can make eggs and glass much more visually interesting. Video after the break.

Continue reading “Photochromic Screen Makes For An Interesting Clock” →

Handheld Game Console Puts Processing Power In The Cartridge

July 12, 2019 by 18 Comments

With the proliferation of cheap screens for use with microcontrollers, we’ve seen a matching proliferation in small handheld gaming projects. Pick your favourite chip, grab a screen off the usual suspects, add some buttons and you’re ready to go. [bobricius] has put a unique spin on this, with an unconventional cartridge-based build.

The main body of the handheld is constructed from attractive black and gold PCBs, and features a screen, some controls and an on/off switch. There’s also a microSD socket is on the board, which interfaces with cartridges which carry the microcontroller. Change the cart, and you can change the game.

[bobricius] has developed carts for a variety of common microcontroller platforms, from the Attiny85 to the venerable ATmega328. As the microSD slot is doing little more then sharing pins for the screen and controls, it’s possible to hook up almost any platform to the handheld. There’s even a design for a Raspberry Pi cart, just for fun.

It’s an entertaining take on the microcontroller handheld concept, and we can’t wait to see where it goes next. It reminds us of the Arduboy, which can even do 3D graphics if you really push it. Video after the break.

The HackadayPrize2019 is Sponsored by:

Continue reading “Handheld Game Console Puts Processing Power In The Cartridge” →

Lessons Learned From An Art Installation Build

July 11, 2019 by 7 Comments

Art installations are an interesting business, which more and more often tend to include electronic or mechanical aspects to their creation. Compared to more mainstream engineering, things in this space are often done quite a bit differently. [Jan Enning-Kleinejan] worked on an installation called Prendre la parole, and shared the lessons learned from the experience.

The installation consisted of a series of individual statues, each with an LED light fitted. Additionally, each statue was fitted with a module that was to play a sound when it detected visitors in proximity. Initial designs used mains power, however for this particular install battery power would be required.

Arduinos, USB power banks and ultrasonic rangefinders were all thrown into the mix to get the job done. DFplayer modules were used to run sound, and Grove System parts were used to enable everything to be hooked up quickly and easily. While this would be a strange choice for a production design, it is common for art projects to lean heavily on rapid prototyping tools. They enable inexperienced users to quickly and effectively whip up a project that works well and at low cost.

[Jan] does a great job of explaining some of the pitfalls faced in the project, as well as reporting that the installation functioned near-flawlessly for 6 months, running 8 hours a day. We love to see a good art piece around these parts, and we’ve likely got something to your tastes – whether you’re into harmonicas, fungus, or Markov chains.

Motorized Lens Controller Techs Up Your Webcam

July 11, 2019 by 13 Comments

If you’re familiar with the DSLR camera market, you’d know that modern lenses are works of technological art. Crammed full of motors and delicate electronic assemblies, they’re bursting with features such as autofocus, optical stabilization and zoom. [Saulius Lukse] has been experimenting with motorized lenses for webcam applications, and has built a controller to make working with them a snap.

The controller is capable of controlling up to 3 stepper motors, as well as a voice coil, which should be enough for the vast majority of lenses out there. Microstepping is supported, which is key for optical systems in which tiny adjustments can make a big difference. The controller speaks USB and I2C, and is now based on an STM32 chip, having been upgraded from an earlier version which used the venerable ATmega328. The board is designed to be as compact as possible, to enable it to neatly fit inside camera and lens assemblies.

The board has been used to successfully control an 18x zoom lens, among others. Combining such a lens with a webcam and a good pan and tilt mechanism would create a highly capable surveillance package, or an excellent vision system for a robot.

It’s not the first time we’ve seen work from [Kurokesu] in these parts – they’ve done work on pedestrian detection before, too.

This Nerf Gun Is Terrifyingly Huge

July 11, 2019 by 10 Comments

Gatling guns were an early attempt at creating a rapid-firing weapon, and were popular amongst armies in the 19th century. Today, the basic design remains in use as a heavy weapon for putting many rounds downrange very quickly. [Ivan Miranda] decided that the Nerf world was missing a piece of the action, and got started on his own design (Youtube link, embedded below).

As per most [Ivan] builds, this one is a glorious pile of 3D printed parts turned into something functional and fun. It’s an ingenious design that’s more a Gatling in spirit than reality as it lacks the multiple barrels of the original, and it uses smart ducting to allow a single electric fan to both fire the foam Nerf balls as well as suck them in to reload the next shot. In testing, it achieved a muzzle velocity of 60 mph, firing at a rate of approximately 10 rounds/second. The presentation is great too, with plenty of cable wrap, meaty switches, and glowing lights to add to the aesthetic. There are even a couple of bright LED lamps on the front to help dazzle your targets into submission.

Once again, [Ivan]’s work is a great example of what is achievable with a 3D printer and smart design. His water jet drive ain’t bad, either. Video after the break.

Continue reading “This Nerf Gun Is Terrifyingly Huge” →