A heart rate monitor can be an important tool for tracking fitness and exertion levels, but what if you want something a bit more interesting style-wise? For a novel idea, be sure to check out the project shown below from “Taste The Code.”

In it, Blagojce Kolicoski turns a handle used for launching rotating toys into something reminiscent of a tricorder from Star Trek.

The build stuffs an Arduino, a pulse sensor, and a tiny OLED display into the handle, which conveniently already had accommodations for three AA batteries. This, along with the monitor’s I2C connection, meant that wiring everything up was quite simple. 

Want to make your own? Instructions are available here, while code can be found on GitHub.

A sandbox game generally refers to an open world computer simulation, but Tim Callinan’s fall semester project takes things in a different direction—an actual sandbox controlled by an Arduino and gShield.

Callinan’s Zen table is capable of producing complicated designs in the sand, using a single steel marble that appears to magically move across the surface by itself.

Underneath the sand assembly is a stepper-controlled gantry that acts like a laser cutter or other CNC tool, dragging the marble around with a powerful magnet. The results are stars, rotating squares, and other kaleidoscopic patterns, beautifully edge-lit with a series of RGB LEDs.

Several other classmates were involved in making this build a reality, including Mark Morello, who wired and programmed the device.

If you’ve ever wanted to plot shapes using an oscilloscope, YouTuber Electronoobs reveals the tricks in his latest video. In it, he draws a Christmas tree, along with a few other shapes, and while that holiday is now past, there’s always the 2019. Of course, you don’t have to wait, as these concepts can be applied to anything you like throughout the year!

In the video, Electronoobs uses an Arduino Nano to produce PWM signals on two channels, filtering each of them with a capacitor and resistor. As he explains, shapes must be fairly simple, and end in the same place they started. Even with these restrictions, once the oscilloscope it turned to x/y plot mode and the signal is tuned in, the results are quite good.

In this tutorial we will use two pins from the Arduino to create fast PWM signals. With a small filter, we change the amplitude of that signal according to the width of the PWM pulse. By that, we can draw shapes on the oscilloscope when in XY mode.

Code for the project can be found in Electronoobs’ write-up here.

If you’d like an easy way to accomplish repetitive biological experiments, the OpenLH presents a great option for automating these tasks. 

The heart of the system is the Arduino Mega-controlled uArm Swift Pro robot, which is equipped with a custom end effector and syringe pump. This enables it to dispense liquids with an average error of just .15 microliters.

A Python/Blockly interface allows the OpenLH to be set up for creative exploration, and because of the arm’s versatility, it could later be modified for 3D printing, laser cutting, or any number of other robotic duties. 

Liquid handling robots are robots that can move liquids with high accuracy allowing to conduct high throughput experiments such as large scale screenings, bioprinting and execution of different protocols in molecular microbiology without a human hand, most liquid handling platforms are limited to standard protocols.

The OpenLH is based on an open source robotic arm (uArm Swift Pro) and allows creative exploration. With the decrease in cost of accurate robotic arms we wanted to create a liquid handling robot that will be easy to assemble, made by available components, will be as accurate as gold standard and will cost less than $1,000. In addition the OpenLH is extendable, meaning more features can be added such as a camera for image analysis and real time decision making or setting the arm on a linear actuator for a wider range. In order to control the arm we made a simple Blockly interface and a picture to print interface block for bioprinting images.

We wanted to build a tool that would be used by students, bioartists, biohackers and community biology labs around the world.

The OpenLH can be seen in the video below, bioprinting with pigment-expressing E. coli bacteria.

While you may not consider in detail how your coffee is roasted, those that produce it must pay special attention to make sure that the end product is consistent. Equipment to help analyze roasted coffee is normally quite expensive, but using a near-infrared sensor, Arduino Uno and Bluetooth module, Spencer Corry was able to make his own analysis setup.

As shown in the video below, after calibration, beans are inserted into the analysis chamber using a tryer scoop. Light is shined onto the roasted beans, and the intensity of the reflected near-infrared radiation is analyzed in six different wavelengths. Intensity data is then transmitted via Bluetooth to a smart device, which can be used to make sure things are roasted perfectly.

There has recently been a growth of small roasting companies offering custom in-house roasts. These companies are looking for less expensive alternatives to hiring and training a roast master or using the expensive Agtron Process Analyzer. The Degree of Roast Infrared Analyzer for Coffee Roasters, as described in this document, is meant to be an inexpensive means of measuring the degree of roast of coffee beans. The Degree of Roast Infrared Analyzer uses a tryer, a tool found on coffee roasters used to sample the coffee during roasting, to hold a sample of coffee. The tryer is inserted into the analyzer where the AS7263 NIR Spectral sensor is used to measure 6 different infrared bands (610, 680, 730, 760, 810, and 860nm). The reflectance measurements are transmitted via Bluetooth and can then be correlated to the degree of roast. The analyzer must first be calibrated by pressing a button on the inside of the box in which the PVC is used as a white balance as it has a relatively flat reflectance in the spectral range detected by the sensor.

For this build, YouTuber DIY Perspective goes through the process of constructing a scrolling text display with two 8×8 matrices. 

His instructions, along with an excellent video, go through the process from the very basics, including things that many would take for granted, like installing the Arduino IDE. For this reason, it could be a great introduction for those that are new to the maker electronics scene.

The device is controlled via an Arduino Nano and can be powered by an 18650 battery or wall charger. While relatively simple electronics-wise, what really sets this project apart is the beautifully finished wooden enclosure. It’s held together with glue, and nicely sealed with a single screw!

If you enjoy model rocketry, you may wonder just what the thrust curve of the motors you’re using looks like. In order to answer that question, YouTuber ElementalMaker decided to construct his own test stand using an Arduino Uno coupled to a 10Kg load cell with an HX711 amplifier board. The test procedure is started with a little red button, and after warning LED blinks away for 10 seconds, it activates a relay and fires the motor under into the stand.

The experimental setup seen in the video yields successful thrust curves for both a ½ inch and ¾ inch motor. As you might expect, the ¾ produces more thrust than its smaller cousin, though at 2,683 grams versus the ½ inch motor’s 658, it’s an impressive difference indeed. 

The heart of the stand is a common load cell (the sort of thing you’d find in a digital scale) coupled with a HX711 amplifier board mounted between two plates, with a small section of vertical PVC pipe attached to the topmost plate to serve as a motor mount. This configuration is capable of measuring up to 10 kilograms with an 80Hz sample rate, which is critically important at this type of rocket motors only burn for a few seconds to begin with. The sensor produces hundreds of data points during the short duration of the build, which is perfect for graphing the motor’s thrust curve over time.

Given such a small window in which to make measurements, [ElementalMaker] didn’t want to leave anything to chance. So rather than manually igniting the motor and triggering the data collection, the stand’s onboard Arduino does both automatically. Pressing the red button on the stand starts a countdown procedure complete with flashing LED, after which a relay is used to energize a nichrome wire “electronic match” stuck inside the motor.

The project is based on a paper archived here if you’d like to examine the design.

Sensors like the TCS34725 from Adafruit can detect a single color. It stands to reason then, that if you were to aim this sensor at a multitude of points and record the resulting data, you could have a one-pixel camera. As seen here, Tucker Shannon decided to take this concept and run with it, constructing his own with an Arduino Uno and a pair of stepper motors.

The device looks like something akin to some sort of auto-turret, and directs the sensor in a square spiral for image acquisition. The resulting pictures are certainly low-res, but good enough to pick out recognizable forms with a little imagination. 

The color sensor tells the Arduino what color it “sees” at any given time. By pointing it at every single point within a field of view, I can record these colors and use them later to reconstruct an image.

Using two stepper motors, the camera points the sensor at every “pixel” within the photo and records what it sees. It uses these values to “paint” a picture of whats in front of it!

Components include: 1x Arduino Uno, 1x Adafruit RGB Color Sensor TCS34725, x2 BYJ-48 Stepper motor with drivers, x1 3mm OD aluminum tube, x20 M3x6mm fasteners. Alternatively a photoresistor can be used in place of the RGB sensor for black and white photos!

Code for the project can be found on GitHub, and print files are on Thingiverse if you’d like to build your own!

Drones come in many shapes and sizes, but for the most part their motor pods are fixed during flight. Inspired by the way birds can fold their wings, researchers from the University of Zurich and EPFL have come up with a quadcopter capable of changing motor orientation dynamically in mid-air. This allows the nominally X-shaped drone to fold itself into tight spaces, and even configure itself for optimal handling.

Flight control is handled by an advanced Snapdragon quad-core computer, while the servos that actuate the motor arms are controlled using an Arduino Nano. 

An interview about the project is available on IEEE Spectrum, while the Foldable Drone’s research paper, along with several more videos, can be found here.

All of us have daily tasks we need to perform, but what if you often forget whether you’ve done something, or simply need to give your child a little extra motivation? One great way would be Simon Prickett’s Arduino Task Tracker, inspired by Simone Giertz’s Every Day Calendar. 

Prickett’s clean-looking device is built into an electrical junction box, which holds the guts, including an Arduino Uno inside. It also exposes eight arcade-style LED buttons on top.

After you, or in this case Prickett’s son, complete a chore, press one of the seven green buttons. Once they are all lit, the Arduino Task Tracker produces a “victory roll” sequence. The eighth red button is then used to start the week over again. 

Sound like something you’d like to recreate? Code and more info for the project can be found GitHub.