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With the current coronavirus situation, we’ve been encouraged to wash our hands regularly for 20 seconds – or approximately how long it takes you to hum “Happy Birthday” from beginning to end twice. That sounds easy enough, but do you really do this every time? What you need is some sort of automatic timer, perhaps with a dial gauge for easy visual reference. 

As it just so happens, Gautam Bose and Lucas Ochoa built such a device with an Arduino Uno. The aptly named Wash-A-Lot-Bot detects a person’s hands in front of it via an ultrasonic sensor, then ticks a dial timer from 0 to 20 (or rather 20 to DONE!) using a micro servo. 

This simple setup can be made with little more than scissors and tape, making it a great way to learn about Arduino and programming while you’re stuck indoors.

Whether it’s with an old friend or new acquaintance, we’ve all had those awkward gaps in conversation. Do you speak next, or let the other person lead the discussion? If that’s not happening naturally, then SASSIE, or “System for Awkward Silence Solution and Interaction Enhancer,” is here to help.

The cylindrical device detects audio feedback via a pair of microphones positioned near each person in a conversation. When a sufficient silence is detected, SASSIE pops a flag out and rotates to indicate who needs to talk. If that wasn’t enough of a hint, it also audibly tells that person to say something. 

SASSIE is powered by dual Arduino Uno boards, one of which takes care of the bulk of the control functions, while the other actuates the stepper to spin the top indicator.

What does one do with over 1,000 LEDs, white acrylic, and 288 IR sensors? If you’re Redditor “jordy_essen,” you create an interactive light panel.

In one mode, the user pull a reflective tool across the sensors to draw a paths, with potentiometers implemented to select the color. It can also be set up to play a sort of whack-a-mole game, where one has to activate the sensor in the same area where it illuminates.

For this amazing device, jordy_essen uses not one, or even two, but six Arduino Mega boards to drive the LEDs directly — in turn controlled by a webpage running on a Raspberry Pi. If that wasn’t enough hardware, an Uno is tasked with taking inputs from the color potentiometers. 

It’s a brilliant project in any sense of the word!

Loop antennas for ham radios use heavy duty variable capacitors for tuning. Since such capacitors need to be physically turned for adjustment, radio enthusiast Jose B.O. made his own remote rig using an Arduino Uno and CNC shield.

The CNC setup allows stepper motors to rotate through a range of angles for frequency selection, and three antennas can be controlled via separate Pololu A4988 driver modules. An optical encoder is used for control, along with buttons for preset frequencies, and a 16×2 I2C LCD display provides visual feedback. Microswitches are implemented to set the upper and lower bounds for the stepper motors.

More info is available in the project’s write-up and the videos below show the system in action.

When you step out in public, you’ll often be filmed by a number of cameras and perhaps even be analyzed by tracking software of some kind. The Watchman robot head by Graham Jessup, however, makes this incredibly obvious as it detects and recognizes facial movements, then causes a pair of eyeballs to follow you around.

The 3D-printed system — which is a modified version of Tjhazi’s Doorman — uses a Raspberry Pi Camera to capture a live video feed, along with a Raspberry Pi Zero and a Google AIY HAT for analysis.

This setup passes info on to an Arduino Uno that actuates the eyeballs via a 16-channel servo shield and a number of servos. The device can follow Jessup up, down, left, and right, making for a very creepy robot indeed!

After being given a 2009 MacBook, John Forsyth decided to use it to start a 1976 Jeep via voice control.

The build uses the laptop’s Enhanced Dictation functionality to convert text into speech, and when a Python program receives the proper keywords, it sends an “H” character over serial to an Arduino Uno to activate the vehicle.

The Uno uses a transistor to control a 12V relay, which passes current to the Jeep’s starter solenoid. After a short delay, the MacBook then transmits an “L” command to have it release the relay, ready to do the job again when needed!

As a fan of Iron Man, Forsyth channeled his inner Tony Stark and even programmed the system to respond to “JARVIS, let’s get things going!”

Researchers in Thailand have developed a ZigBee-based wireless monitoring solution for off-grid PV installations capable of tracking the sun across the sky, tilting the panel hourly. The elevation for the setup is adjusted manually once per month for optimum energy collection. The prototype is controlled by a local Arduino Uno board, along an H-bridge motor driver to actuate the motor and a 12V battery that’s charged entirely by solar power.

The system features a half-dozen sensors for measuring battery terminal voltage, solar voltage, solar current, current to the DC-DC converter, the temperature of the power transistor of DC-DC converter, and the tilt angle of solar panels according to the voltage across the potentiometer. 

Data is transmitted wirelessly via an XBee ZNet 2.5 module to a remote Uno with an XBee shield. The real-time information is then passed on to and analyzed by a computer, which is also used to set the system’s time.

More details on the project can be found in the team’s paper.

Wireless sensing is an excellent approach for remotely operated solar power system. Not only being able to get the sensor data, such as voltage, current, and temperature, the system can also have a proper control for tracking the Sun and sensing real-time data from a controller. In order to absorb the maximum energy by solar cells, it needs to track the Sun with proper angles. Arduino, H-bridge motor driver circuit, and Direct Current (DC) motor are used to alter the tilt angle of the solar Photovoltaic (PV) panel following the Sun while the azimuth and the elevation angles are fixed at noon. Unlike the traditional way, the tilt rotation is proposed to be stepped hourly. The solar PV panel is tilted  in advance of current time to the west to produce more output voltage during an hour. As a result, the system is simple while providing good solar-tracking results and efficient power outputs.

The South Florida Science Center recently commissioned a beautiful new 10” aperture refactor telescope. Its dome, however, was opened by hand; so in an effort to modernize this part of the setup, Andres Paris and his brother “patanwilson” added a windshield wiper-style DC motor to automate the process.

The “window to the heavens” is now operated by an Arduino Uno via a high current H-bridge capable of passing along up to 20 amps. User interface is provided by an IR remote control and reed switches stop the door’s motion at the appropriate points. 

A pair of 12V batteries enable the system to move within the dome and the voltage displays — that can be turned off remotely — to show how much power is left.

More details on the project can be found on Reddit.

Stars appear to stand still, but wait a few minutes and they won’t be in quite the same place. This means that if you want to take a long-exposure image of the sky with your DSLR you’ll have to either embrace the streaks, or use tracking hardware to compensate for this movement. Naturally, this specialized equipment can be quite expensive, but a seen here, you can now make your own 3D-printed OpenAstroTracker controlled by an Arduino Uno.

The device features a 16×2 LED display/keypad shield, along with an optional Bluetooth module for interface. When set up, it slowly rotates the camera to compensate for star movements via two steppers on a gimbal assembly. 

Print files for the OpenAstroTracker are available on Thingiverse and code can be found on GitHub if you’d like to examine the design or even build your own. Its creator also plans to sell it as a DIY kit — and you can sign up to be notified when it’s available.

Yu-Gi-Oh! and other similar card games can be quite popular, but actually finding a group to play with can be challenging. Online games, on the other hand, have their advantages yet render your deck pretty much useless. As a way to combine these two worlds, Augusto Masetti has created a prototype Dual Disk System that will allow you to play with real cards in a virtual playfield.

To play, participants attach NFC stickers inside a card sleeve, which are scanned by an NFC reader controlled by an Arduino Uno. The card ID is then compared to the YGOProDeck API database via a computer, giving players a tactile element to this virtual competition.

Masetti’s project is still a work in progress, though we can’t wait to see the final version!



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