After a longish hiatus, we were pleased to see a new video from [Afroman], one of the most accessible and well-spoken teachers the internet has to offer. If you’re new to electronics, see the previous sentence and resolve to check out his excellent videos. The new one is all about servos, and it culminates in a simple build that provides a foundation for exploring robotics.

[Afroman] leaves no gear unturned in his tour de servo, which is embedded after the break. He explains the differences between open vs. closed loop motor systems, discusses the different sizes and types of servos available, and walks through the horns and pigtails of using them in projects. Finally, he puts this knowledge to use by building a laser turret based on a pan-tilt platform.

The Arduino-driven turret uses two micro servos controlled with pots to move by degrees in X/Y space. Interestingly, [Afroman] doesn’t program the board in the Arduino IDE using wiring. Instead, he uses an open-source microcontroller language/IDE called XOD that lets you code by building a smart sort of schematic from drag-and-drop components and logic nodes. Draw the connections, assign your I/O pin numbers, and XOD will compile the code and upload it directly to the board.

XOD seems like a good tool for beginners to do rapid prototyping. On the other hand, a look into the generated code reveals a whole lot of wrappers that obfuscate the bits of code that actually do stuff. There doesn’t seem to be a way to shed them, either, so once you design something in XOD, you’re kind of stuck using it to iterate. That said, the generated code is well documented, and someone who knows what they’re looking at could find, for instance, the I/O pin assigned to the blink sketch LED.

Once the novelty of the double laser cat tormentor has subsided, use the other servos in that 5-pack you bought to flip a light switch, control a knob, or play the glockenspiel.

While ’80s-style boomboxes have their own unique character, per hacker “Dancorp’s” excellent mod, it’s clear that they could be improved dramatically with programmable LEDs.

This build uses a capacitive filtering arrangement to feed line out signals from the boombox into an Arduino Uno, which then controls three LED strips.

Two of these strips are arranged around the speaker cones, emitting beautiful LED effects to go along with the music playing, while the third can be used to light up the built-in VU meters.

A schematic along with Arduino code are available on Dancorp’s write-up. It looks like a fairly accessible project, especially given the extra space available in electronics from that era.

Up until the present day, if you need butter, you simply ask another human to “pass the butter,” leading to minor inconvenience and awkwardness. Engineering students in Brussels have come up with a novel solution: a robot that brings the butter to you!

The robot, inspired by Rick and Morty’s Butter Bot, is powered by an Arduino Uno and summoned to hungry humans via an infrared remote control.

When the signal detected by onboard IR sensors, the robot moves over using continuous-rotation modded servos, then flips its cap-like lid to reveal the butter inside.

Want a Butbot of your own? You can find the build process and code in the student team’s write-up here.

In order to create the ultimate off-road RC rig, “asrebro” designed his own six-wheeled vehicle, operated with the help of Arduino.

To give it decent range and reliability, the hacker turned to a stock transmitter and receiver, but routed the PWM signals onboard to a Mega. The Arduino uses a pair of H-bridge boards to drive all six motors/wheels for tank-like movement.

Since an Arduino is used, this opens up a wide range of manual and automatic control options, and could even be used to power robotic accessories like a gripper or gimbal with a camera.

I decided to build a bigger robot that will easily overcome various obstacles on its way and will be able to move with a load of at least a dozen kilos. I also assumed that the robot should be able to cope in difficult terrain such as sand, snow and rubble. To make it possible, I built a 6-wheel [aluminum and duralumin] chassis equipped with 6 motors of sufficient high power and suitable motor driver and power supply. I also wanted my robot to be controlled from a long distance (at least 200 meters) so I used a good quality 2.4GHz transmitter and receiver.

You can see it in action below, traversing through a forest near Warsaw, Poland.

The RoboGlove project is a robotic glove by students at the Université Libre de Bruxelles that is designed to assist the wearer when continuously gripping objects.

This is accomplished by a series of three servos that transmit force through cables for the index finger, middle finger, and thumb. Control is via an Arduino Uno, which takes input from pressure sensors in the three finger fixtures, helping the wearer keep gripping when force is initially exerted to close a fist.

The glove has a wire connection that links the fingers to some servo motors: a wire is attached to the extremity of the finger and to the servo, so when the servo turns, the wire is pulled and the finger is flexed. In this way, by controlling the grip done by the user through some pressure sensors in the extremity of the fingers, we are able to actuate the motors in a controlled way and help the gripping by bending the finger proportionally to the rotation of the motors and so to the rolling up of the wires. In this way we should be able either to allow weak people to grip objects or help even people in physiological conditions to grip objects and to keep it without any effort.

While still a prototype, it’s an interesting device that could be developed further into a very helpful augmentation. You can see it in action in the video below!

After finding an organ left outside to rot, hacker “tinkartank” decided to use it for his own purposes, adding push buttons under each key as inputs to an Arduino Mega.

He also reused the control rods with potentiometers as a secondary input method, and added a tiny OLED to display the system’s menu. With this unique interface setup, the Mega drives a MOS6581 SID chip—originally used to produce sound on the Commodore 64—for music generation, and can interface with Eurorack modules as needed.

Want to see more? Be sure check out the SID organ in action below, and read the entire project write-up here.

If you need a MIDI device that can be programmed as your own unique light and sound controller, then Jon Bumstead’s LED Eclipse may be just what you’re looking for.

The circular device, roughly the diameter of a large plate, is constructed out of 30 layers of MDF, and boasts 10 capacitive sensors made with copper strips, as well as 10 corresponding programmable LEDs.

An Arduino Uno powers the assembly, which can be seen being played like a multi-player electronic piano towards the end of the video below. It can also be used as a Simon-style game, and even a light display—though you could program it for any other application you desire!

Did you know that embossing machines needed to generate Braille characters can cost thousands of dollars? After finding this out, hacker Carlos Campos decided to design and build his own using 3D-printed parts, along with an Arduino Mega and a RAMPS board for control.

Instead of punching each dot, the device pushes a pin out onto the paper, then rolls the dot onto it from the other side, leading to a much quieter operation than normal machines.

Check out the clips below to see the pin actuator by itself and the embosser in action. More details and videos can also be found on Facebook. The project is still in the experimental stages, so collaborators are invited to help turn it into an even more useful implement.

There’s something about impressing strangers on the Internet that brings out the best in us. Honestly, we wouldn’t be able to run this site otherwise. A perfect example of this phenomenon is the annual Reddit Secret Santa, where users are challenged to come up with thoughtful gifts for somebody they’ve never even met before.

For his entry into this yearly demonstration of creativity, [Harrison Pace] wanted to do something that showcased his improving electronic skills while also providing something entertaining to the recipient. So he came up with a box of goodies which is unlocked by the successful completion of a built-in trivia game tailored around their interests. If this is how he treats strangers, we can’t wait to see what he does for his friends.

There’s quite a bit of hardware hidden under the hood of this bedazzled gift box. The primary functions of the box are handled by an Arduino Nano; which runs the trivia game and provides user interaction via a 16×2 LCD, three push buttons, and a buzzer. Once the trivia game is complete, a servo is used to unlock the box and allow the recipient access to the physical gifts.

But that’s not the only trick this box has hidden inside. Once the main trivia game is complete, a ESP8266 kicks into action and advertises an access point the user can connect to. This starts the second level of challenges and gifts, which includes a code breaking challenge and gifted software licenses.

The project wasn’t all smooth sailing though. [Harrison] admits that his skills are still developing, and there were a few lessons learned during this project he is unlikely to forget in the future. Some Magic Smoke managed to escape when he connected his 5V Arduino directly to the 3.3V ESP8266, but at least it was a fairly cheap mistake and he had spares on hand to get the project completed anyway.

This project is reminiscent of reverse geocache boxes which only open when moved to a certain location, but the trivia aspect makes it perfect even for those of us who don’t want to put pants on just to receive our Internet gifts.

If you thought the power of levitation was only available to magicians (and perhaps magnets) then check out this amazing project from Asier Marzo. It uses an Arduino Mega to control an 8×8 array of ultrasonic transducers, which when carefully coordinated using a simulation program, not only can suspend a particle but cause it to move around the grid of transducers.

You can find a summary of this kind of device’s capabilities in Marzo’s write-up, including haptic feedback, use as a directional speaker, and even levitating liquids in a standing wave setup.

We present Ultraino, a modular, inexpensive, and open platform that provides hardware, software and example applications specifically aimed at controlling the transmission of narrowband airborne ultrasound. The software can be used to define array geometries, simulate the acoustic field in real time and control the connected driver boards. The driver board design is based on an Arduino Mega and can control 64 channels with a square wave of up to 17 Vpp and ?/5 phase resolution. Multiple boards can be chained together to increase the number of channels. 40 kHz arrays with flat and spherical geometries are demonstrated for parametric audio generation, acoustic levitation and haptic feedback.

You can also skip to 8:30 in the video below to see it manipulating a particle, or to 9:30 where several individual drops of alcohol and food coloring are able to float in mid-air.