Mechanical typewriters are, for the most part, a thing of the past. Though the tactile feedback of these machines is interesting, as is the ability to directly mark on a piece of paper, they lack the important ability to input instructions into a modern computer. Konstantin Schauwecker, not satisfied with this analog-only output, decided to retrofit a German Olympia Monica typewriter as a unique digital user input device.

To accomplish this, he created a PCB with phototransistors that sense when the linkages for each key are pushed down. The result is a keyboard that functions perfectly well as a manual typewriter, and pushes this data to a computer using an Arduino Leonardo.

I modified a vintage type writer to function as a USB keyboard using an Arduino and 50 phototransistors. The typewriter is a German Olympia Monica that I bought at a local flea market. For this project I created a simple PCB that carries the phototransistors and several multiplexers and decoders. The PCB is connected to the Arduino through a ribbon cable. I used an Arduino Leonardo, which can function as a USB input device.

Check out Schauwecker’s write-up for more info on this clever build.

If you work in a lab, the last thing you want is someone barging in when you’re about to complete your latest experiment or build, disturbing all of your hard work. You could use a paper note, or perhaps lock the doors, but if you’d like to inform potential disruptors of what you’re doing and give them a way to signal you, this system looks very useful.

The device, which is installed in a psychology lab’s door, uses an Arduino Uno to display an LED for “Experiment In Progress” or “Clear,” and has a backlit LCD screen below for more explanation. The screen’s backlight powers up via a sonar sensor if someone approaches, and messages can be updated over Bluetooth.

Finally, if you’d like to get the person inside’s attention, it even a doorbell feature that blinks a light and optionally beeps. For more info on the project, check out its creator’s Imgur set or Reddit post.

You can switch a tattoo machine on and off with a foot pedal, but this can be an issue when it’s time to pack it up with other gear that needs to be kept ultra-clean. To address this problem, YouTuber “Wildman Tech” made an Arduino-powered device in the shape of a beautiful wooden pyramid to control a tattoo gun with the wave of one’s hand.

Electronics-wise, the setup is fairly simple. An Arduino Uno detects the tattoo artist’s gestures via a distance sensor, and signals the machine with an on or off output.

This project uses an Arduino Uno, a distance sensor module, and an FET driver transistor module. They both take their power from the Arduino main board. The distance sensor output is fed into pin 2 on the Arduino and the FET driver input is taken from pin 9.

You can see more of Wildman Tech’s touchless switch, including its code, in the video below!

With some projects, your goal is to get it working to prove out a concept for a larger project, or simply to satisfy your curiosity. On the other hand, sometimes you want your creation to look great. That was the case here, as this electromechanical clock integrates several different types of metal along with a chain drive into something that’s as much a work of art as it is a practical timekeeping tool.

Upon startup, the device is able to auto-calibrate using a clever sensor setup on the hour hand wheel to make sure it’s at 12:00 noon/midnight, then uses the Arduino Yún‘s built-in WiFi support to check the time off of the Internet and configure itself accordingly.

This clock was designed, machined and assembled, every piece from scratch (apart from a couple of the small chain sprockets and chains themselves). The timekeeping and motor/position control software was also developed and programmed 100% from scratch as well. All the parts are made out of a combination of copper, brass, steel, aluminum, and stainless, and the assembly is driven by an Arduino Yún running a NEMA style stepper motor, and Honeywell automation Hall effect sensors for the mechanical position readings.

You can find more details in the video seen below, and on its creator’s Reddit post.

After building a bicycle that could travel across town while making music, Sam Battle now taken things in a different direction. Synth Bike 3.0, which will be on display at the Science Center Dublin until September, is set up on a training fixture so that you can pedal it indoors rain or shine. This version also features a simplified control panel on the handlebars, allowing it to be played by anyone at a tempo controlled by the rear wheel’s speed.

Battle’s YouTube channel is named “LOOK MUM NO COMPUTER” however, this apparently doesn’t count microcontrollers. Hidden in the externally clean-looking handlebar groove box is a total of 12 Arduino Nano boards, along with a maze of wiring, strip circuit boards, frequency central PCBs, a SparkFun WAV trigger, and some other electronics. There’s even built-in speakers on the sides to output the created sounds.

Be sure to check out Synth Bike 3.0’s New Atlas write-up for more info on the project.

Fidget spinners are currently very popular, and if you get one you’ll certainly want to spin and spin, maybe thinking you’ll never put it down. Unfortunately, like Nikodem Bartnik, you’ll eventually get bored with this device. Perhaps setting it aside forever. However, as Bartnik puts it, “Spinner has to be spinned,” so he came up with a robotic device to do this for him.

The resulting robot consists of two small servos, along with two 3D-printed linkages, attached to a piece of wood. A spinner is also affixed to the same piece of wood with a bolt, which is spun by the servos under Arduino Uno control.

Check out Bartnik’s Instructables write-up to see how it was done, along with the code and STL files needed to create your own!

When you see a plastic ruler, you wouldn’t normally assume it was destined to become part of a CNC plotter. Maker “lingib,” however, realized their potential to be combined to form plotter arms, in this case actuated by two stepper motors.

The resulting build can expand and contract the resulting shape, allowing a pen at the end point of the two sets of rulers to move back and forth across a piece of paper. Necessary spaces in the plot are provided by a micro servo that can lift the pen/ruler off of the writing surface.

The device is powered by an Arduino Uno, which controls the two NEMA 17 stepper motors via a pair of EasyDriver Modules. You can find more details about how to create one of these, including code and how the geometry behind it works, on its Instructables page.

Computer vision has traditionally relied on an assortment of rather involved components. On the other hand, everything you need to do this complicated task is readily available on an Android phone. The clever setup seen in the video here uses a smartphone to capture and process images, then send out a signal over Bluetooth to tell which way the device needs to be adjusted in order to focus on a nearby face.

An HC-05 Bluetooth module receives this signal and passes it to two servo motors via an Arduino Nano, moving the phone left/right and up/down.

You can find the Arduino code for this project on CircuitDigest, and the Android Processing code can be downloaded there as a compressed folder.

Though time may be relative, unless you’re planning on doing a lot of space travel, slowing things down in real life is “notoriously” difficult. On the other hand, with carefully-coordinated vibrations and lighting, the “sLOMO” device is able to make objects such as a feather or plant appear to move in slow motion with the naked eye.

Inspired by Jeff Lieberman’s Slow Dance Frame, this project is made out of a readily available IKEA Ribba frame, and the object inside vibrates using an electromagnet. An Arduino Nano controls this magnet and pulses a double-row LED strip, in order to make the item appear to slow down, or even distort itself into multiple overlapping images.

Want to build your own? Check out the excellent write-up on Instructables, and see the magical frame in action below!

If you have even a passing familiarity with how to play a piano, you know that there are a bunch of long white keys, with a lesser number of black keys in a nearly-universal arrangement. On the other hand, like the standard and much lesser-known Dvorak keyboard for typing, there are alternatives. One such alternative is the Jankó keyboard, which Ben Bradley decided to reconstruct for the Moog Werkstatt using a capacitive touch sensor setup.

His new instrument, which as of his write-up only had 13 keys connected, was constructed for the 2017 Moog Hackathon at Georgia Tech. It uses an Arduino Mega for control along with four MPR121 capacitive touch breakout boards, and as seen in the video below, can be played quite well after only one day of practice!

You can find more details on his build, including its Arduino code, on the Freeside Atlanta website and check out its feature on Hackaday here.

(Photo: Nathan Burnham)