In skateboarding, the ollie is a fundamental trick used to leap onto, over or off obstacles, or over gaps of unfriendly terrain such as grass or stairs. But how do you know just how sick your ollie actually was? Josh Sheldon has a solution.

The Maker has built a device that judges the sickness of your ollie and visualizes your score, rewarding the best ones with the chiming of a cowbell. Sheldon describes the project as something “like one of those hammer games at carnivals, but instead of trying to hit that thing with a hammer as hard as you can, the goal is to land the sickest ollie.”

The aptly named Sick Ollie Machine consists of two parts: a stand with LEDs and the skateboard itself. Underneath the board is an Arduino Uno, a 9V battery, and an accelerometer. The stand is equipped with another Arduino, a relay, and an RGB LED strip that goes up mast, as well as a solenoid on top. When the relay closes, the solenoid hits the bell. Both units also contain a wireless transmitter, allowing them to communicate with one another.

Watch Sheldon discuss his project in more detail below!

Unlike most cars today, deepsyx’s old Opel Astra did not have a tachometer. So what’s a Maker to do? Build your own, of course.

To accomplish this, deepsyx used an Arduino Uno along with a few LEDs. The first LED turns on at 4000 RPM, while the others light up with every 500 RPM increment. At 5800 RPM, however, all the LEDs flash as a warning. There’s even a serial output of the RPM value, so logging real-time data can be a possible enhancement down the road.

I started by cutting a 5cm x 1.5cm piece of an old credit cart, drilled 4 holes in it, painted it black and glued 4 LED diodes to it. Then I soldered 220ohm resistors to each positive LED pin and used a common ground. I connected them to an Arduino via 5 x 30cm jumpers and hid the Arduino in a hole under the wheel. I connected the Arduino data pin via voltage divider to the signal pin of the coil and used an old phone charger to power the Arduino. In order to work, I shared the phone charger and Arduino’s grounds.

Intrigued? You can read more about this project on deepsyx’sGitHub page and over on Hackaday.

[Stanley] wanted to make a laser projector but all he could find online were one’s using expensive galvanometer scanners. So instead he came up with his own solution that is to be admired for its simplicity and its adaptation of what he could find.

At its heart is an Arduino Uno and an Adafruit Motor Shield v2. The green laser is turned on and off by the Arduino through a transistor. But the part that makes this really a fun machine to watch at work are the two stepper motors and two mirrors that reflect the laser in the X and Y directions. The mirrors are rectangles cut from a hard disk platter, which if you’ve ever seen one, is very reflective. The servos tilt the mirrors at high speed, fast enough to make the resulting projection on the wall appear almost a solid shape, depending on the image.

He’s even written a Windows application (in C#) for remotely controlling the projector through bluetooth. From its interface you can select from around sixteen predefined shapes, including a what looks like a cat head, a heart, a person and various geometric objects and line configurations.

There is a sort of curving of the lines wherever the image consists of two lines forming an angle, as if the steppers are having trouble with momentum, but that’s probably to be expected given that they’re steppers controlling relatively large mirrors. Or maybe it’s due to twist in the connection between motor shaft and mirror? Check out the video after the break and let us know what you think.

The video’s in three parts: looking at the laser beams in action as you’d see them on a dance floor, then watching the projected images while looking at an insert of the Windows application, and then watching the steppers and mirror doing their rapid movements.

As for the expensive galvanometer scanners we mentioned above, check out this impressive laser projector that uses them. Another method is to use a spinning wheel with mirrors set to different angles, like this one that draws a marquee using a pill box as the wheel. And how about one with no mirrors at all, instead attaching the laser directly to servo motors, though that one does take longer to draw.

Bouncing a laser off of a spinning mirror creates an amazing effect with smoke and fog, but YouTuber “Normal Universe” made it even better with an Arduino.

This video starts out by introducing the concept of “laser sky,” which seems like a fun idea. There is, however, a chance that the mirrors wouldn’t spin, potentially pointing a laser continuously at a bystander, possibly damaging his or her eyes. To prevent this, the YouTuber added a photoresistor and LED to sense the spinning mirrors, then programmed an Arduino Uno to cut off the laser if it’s stopped for whatever reason.

Normal Universe goes on to explain the electronic concept behind it as well as the Arduino code involved, so even if this effect isn’t your cup of tea, the photoresistor/voltage divider setup could still be quite useful.

You can find a detailed breakdown of the project in the video below!

After an accident, Ethan Kadish was paralyzed. His friend, 14-year-old Jacob Smilg, came up with a simple device to help him communicate.

Several years ago, Kadish was struck by lightning, and lost control over his body. Communication with the world took the form of eye blinks for “yes” and “no,” which gave Smilg an idea for a revolutionary, Arduino Uno-based gadget that could help him communicate with people not familiar with this method.

It uses two pads, which Kadish can press with his head. When pressed, the device displays “yes” or “no” on a small LED screen. This allows him to have conversations in a more natural way, which, as seen in the video below around 4:00 it appears to make him very happy!

You can read more about the project on Make:, and keep up with Kadish’s story and progress on the Team Ethan blog. More pictures and videos can be found on Smilg’s Facebook page.

After recently meeting each another in Cologne, Simone Giertz and Laura Kampf decided to put their creative minds together to build a cartoon-inspired robot for Kampf’s dog, Smudo. The idea is fairly straightforward: a device that “makes a dog walk itself” by dangling a piece of sausage in front of their head.

The contraption consists of a lightweight, ergonomic aluminum harness that bends over Smudo, along with an Arduino Uno and a servo motor tasked with wiggling the hot dog around.

You can see how it works and hear more from the creators themselves the video below!

Starting a new project is always an effective way to hone your skills while exploring circuitry and programming. To help improve his engineering chops, Joop Brokking recently bought an inexpensive oscilloscope (a device for visualizing voltage over time in an x-y graph) and connected it to an Arduino Uno. He then shared his findings in a detailed tutorial on YouTube.

In the video below, Brokking is using a Hantek 6022BE 20MHz dual-channel oscilloscope and provides three examples to better understand what can go wrong when building a simple Arduino setup.

Les Boites Mécaniques are a set of four automated boxes that produce music out of wood and metal. These experimental instruments enable anyone to explore the magic of making sound by pressing buttons on a remote, which activate each respective device to vibrate, knock, and rub materials.

The boxes were developed by Kogumi‘s Anatole Buttin and Yan Godat for educational electronic music workshops, and can be played either solo or in unison. There’s even a mode that allows users to control it all via MIDI notes on a computer.

In terms of hardware, each box is equipped with an Arduino Uno, a TLC59711 LED driver, step motors with AccelStepper library and a 3D-printed microstep driver.

You can watch how it all comes together to create a unique sound below!

For his latest project, Dmitry Morozov (aka ::vtol::) has created a robotic machine that uses a microphone to record sounds from its surrounding environment, selecting only the loudest ones. Then, the aptly named “Collector” pieces these noises together in the order they were recorded to form an algorithmic  composition.

First, the Collector records the sounds until it has gathered 100 samples. From there, it plays the result as a loop through a pair of speakers for one minute, so they can be heard by those nearby. While this mode, the recording stops. After that, it erases everything and begins a new search.

The Collector is also equipped with an Arduino Uno for a brain, a servo motor for rotating the mic, and a flashlight to show detected sounds or indicate the sounds during playback mode.

It is a kind of reality re-mixer–by simply removing the silence and pauses between loud sounds and words, it creates the sense of very rhythmical and organized aural experience, which sounds very musical to me.

Intrigued? You can read more and see other photos of the project on its page here.