Author: Zoe Skyforest

3718 Articles

Coil On Plug Ignition For Tiny Engines

December 21, 2020 by 40 Comments

The spark plug was a key invention in the history of the internal combustion engine, allowing combustion to be easily controlled and engines to rev faster than messy earlier designs. Mid-century cars tended to rely on points ignition with a distributor and coil, however more modern designs place a coil on top of each individual spark plug. [Roger Moore] decided to build a similar setup for a small model engine on his workbench.

The rig is built with an Arduino, a flyback transformer, a smattering of MOSFETs and passives, an IGBT and a capacitor. The Arduino outputs PWM through a MOSFET which is stepped up through the transformer, and then charges the capacitor. The capacitor is then discharged into a coil mounted on top of the sparkplug of the single-cylinder engine, which fires the spark. The timing of the spark is determined by a Hall effect sensor reading a magnet placed on the flywheel.

Later development aims to shrink the system further to fit on a V10 design [Roger] is planning to make. It’s been done on a small scale before, and we’d love to see another tiny engine with way too many cylinders. Video after the break.

Continue reading “Coil On Plug Ignition For Tiny Engines” →

World Solar Challenge: How Far In A Solar Car?

December 21, 2020 by 90 Comments

Solar power is a great source of renewable energy, but has always had its limitations. At best, there’s only 1,000 Watts/m2 available at the Earth’s surface on a sunny day, and the limited efficiency of solar panels cuts this down further. It’s such a low amount that solar panels on passenger cars have been limited to menial tasks such as battery tending and running low-power ventilation fans.

However, where some might see an impossibility, others see opportunity. The World Solar Challenge is a competition that has aimed to show the true potential of solar powered transport. Now 30 years since its inception, what used to be impossible is in fact achieved by multiple teams in under one tenth of the original time. To keep competitors on their toes, the rules have been evolving over time, always pushing the boundaries of what’s possible simply with sunlight. This isn’t mainstream transportation; this is an engineering challenge. How far can you go in a solar car?

Continue reading “World Solar Challenge: How Far In A Solar Car?” →

We Bet You’ve Never Seen A Pink Denture Synth

December 21, 2020 by 18 Comments

At one end of the synthesizer world, there stands commercial instruments designed for the ultimate in sound quality and performance, tailored to the needs of professional musicians. On the other, there are weird, wacky prototypes and artistic builds that aim to challenge our conception of what a synth should be. The VOC-25 by [Love Hultén] falls firmly in the latter category.

The synth is built around the Axoloti Core, a microcontroller board set up for audio experimentation. Packing stereo DACs and ADCs, and MIDI input and output, it’s the perfect base for such a project. Loaded up with vocal samples, it’s played by a keyboard in a fairly typical sense. Where things get interesting is the panel containing 25 sets of plastic teeth. The teeth open and close when the user plays the corresponding note, thanks to a solenoid. Along with the clacking sound of the machinery and pearly whites themselves, it adds quite a creepy vibe to the piece.

With its clean pastel enclosure, we can imagine this piece as the star of an avant-garde filmclip, or merely something to terrify children at a Maker Faire. It’s a fun build, to be sure. We’ve seen some other great experimental synths over the years, too – this 48 Game Boy build comes to mind. Video after the break.

Continue reading “We Bet You’ve Never Seen A Pink Denture Synth” →

Weather Note Tells You What You Need To Know, And No More

December 20, 2020 by 1 Comment

Smartphones are portals to an overwhelming torrent of information. Yes, they’re a great way to find out the time, your bus schedule, and the weather, but they’re also full of buzzers and bells going off every three minutes to remind you that your uncle has reposted a photo of the fish he caught ten years ago. Sometimes, it’s better to display just the essentials, and that’s what Weather Note does.

It’s built around the Adafruit Feather Huzzah, a devboard built around the venerable ESP8266. It’s a great base for an Internet of Things project like this one, with WiFi built-in and ready to go. The Weather Note talks to a variety of online platforms to scrape weather data and helpful reminders, with the assistance of If This Then That, or IFTTT. Reminders to walk the dog or get some milk are displayed on a small OLED screen, while there’s also a bunch of alphanumeric displays for other information. WS2812 LEDs are used behind a shadowbox to display weather conditions, with cute cloud, rain, and sun icons. It’s all wrapped up in a tidy frame perfect for the mantlepiece or breakfast table.

It’s a great build to learn about programming for the Internet of Things, and with those bright LED displays, it’s probably a viable nightlight too. It’s a rare project that can both tell you about the weather and keep you from stubbing your toe in the kitchen, after all. Those desiring a stealthier build should consider going down the smart mirror route instead. Video after the break.

Continue reading “Weather Note Tells You What You Need To Know, And No More” →

Splash Droplet Photos

December 20, 2020 by 10 Comments

Water droplets are beautiful things, though photographing them can prove difficult without a little help. Precise timing is key, and that’s what led [Alex Pikkert] to build a timing controller to help nail the perfect shot.

It’s a job that’s ideally suited for the average microcontroller. In this case, [Alex] chose the venerable Arduino Uno. Paired with a bunch of buttons and a 16 x 2 character LCD, it has a simple-to-navigate interface for dialling in a shot. The trick to splash and droplet photography is to first open a valve to release a droplet, and then fire a flash a set time after to capture the droplet in flight, after it’s hit the surface of the liquid. [Alex]’s design uses a MOSFET to trigger the water valve, and optoisolators to safely trigger the flash and camera.

[Alex] has gotten some impressive results with the rig, and it would serve as a great starting point for anyone looking to get into the field. We’ve seen similar builds before, too. If you’ve got your own fancy photography rig for those otherwise-impossible shots, be sure to drop us a line!

Hamster Wheel Tacho Measures Tiny Pet Performance

December 19, 2020 by 5 Comments

Humans often like to monitor their exercise habits with the use of a pedometer, which tracks steps taken during a walk. Such devices are a little cumbersome for smaller creatures however, but no matter. Hamsters tend to get most of their workouts done on a wheel anyway, so it’s simple enough to instrument the equipment instead.

The build is a simple tachometer, using an infrared emitter and sensor pair to read the rotation speed of the hamster wheel. The wheel itself is light-colored plastic, so a strip of black felt is used to create a non-reflective section, creating a pulse one per revolution that can be read by the Adafruit Feather 32U4 running the show. Data on peak speed and total rotations is available for tracking the exercise habits of the hamster in question, output on a set of 14-segment displays.

It’s a fun project, and one that would be a great way to teach kids about pet care and basic embedded systems. Hamster performance could even be uploaded to the cloud with a more advanced build, and training milestones linked to rewards a la Premier League footballers. At the end of the day, a hamster wheel is just an exercise bike for our four-legged friends, and we’ve seen those hacked too. Video after the break.

Continue reading “Hamster Wheel Tacho Measures Tiny Pet Performance” →

Protect Your Tomatoes With A 9V Battery

December 19, 2020 by 57 Comments

Growing fresh vegetables at home is a popular pastime, even moreso in a year when we’ve all been locked inside. However pests can easily spoil a harvest, potentially putting a lot of hard work down the drain. [Matt] of [DIY Perks] isn’t one to give up his tomatoes without a fight, however, and came up with a solution to protect his plants.

The trick is to take advantage of the mildly conductive slime excreted by snails as they travel along the ground. To protect potted plants, [Matt] places two strips of copper tape around the perimeter of the pot, spaced about a centimeter apart. Each strip is connected to one terminal of a 9 V battery. When a snail attempts to cross the strips, it completes a circuit between the two, and the electrical current that flows irritates the snail, forcing it to retreat.

[Matt] notes that no snails were harmed in the making of the video, and that the solution is far kinder to the slimy critters than poisons or traps. He also goes so far as to demonstrate alternative solutions for garden beds, as well. We’ve more commonly seen [Matt] working with lighting, though it’s great to see he has a bit of a green thumb, too. Video after the break.

Continue reading “Protect Your Tomatoes With A 9V Battery” →