Inventor Artist Darcy Whyte wanted a drawing robot that was light enough to carry around, and could quickly produce drawings. Naturally, he turned to an Arduino Uno, along with a CNC shield and a trio of A4988 stepper drivers. These control a NEMA 8 and two NEMA17 stepper motors in a gantry-style artistic setup.

The build is able to drag a marker across a page, apparently varying pressure applied with the z-axis, and thus how much ink is applied. In another mode, a pen can be used, which wobbles back and forth to create volume when needed. 

Both methods, as seen in the clips below, can sketch a very recognizable—though certainly distinct—portrait of Marilyn Monroe, or presumably whatever other image you choose to program in.

Most pools feature a powered pump system to help filter out debris, but what if your water level gets too low? Pumps designed for ‘wet’ operation generally don’t work well when water isn’t present, so Luc Brun came up with an innovative monitoring solution dubbed “BluePump.”

His setup uses an Arduino Nano and an ACS712 sensor to observe both voltage and current, detecting the phase shift between the two. If this shift is too large, this indicates dry operation, and shuts down the pump via a relay until things are resolved. 

To complement this ability, BluePump also includes a temperature sensor, an RTC, and a Bluetooth module, allowing it to schedule cleanings as needed, or work under human control via a custom Android app.

Skittles candies come in various vibrant colors. While they may be a tasty treat, JohnO3 had another idea: to create an amazing automated display for the little circles. 

His device, dubbed the “Skittle Pixel8r,” uses an Arduino Mega to pull a dispensing funnel between one of 46 channels, covered on one side with a piece of glass.

On top of the shuttle mechanism, eight boxes release the correct flavor/color into an intermediate tube via individual metal gear servos. The Arduino then commands the linear axis to move the funnel to the appropriate bin. This process is repeated 2,760 times until an image, measuring up to 785 x 610mm (31 x 24 inches), is completed. 

The Skittle Pixel8r an incredible build, and perhaps we could see it expanded even further to not just dispense, but also sort Skittles as an all-in-one auto art installation! Code and files for the project can be found here.

After constructing a regen (regenerative) radio receiver several years ago, Michael LeBlanc decided to upgrade to a direct conversion receiver in order to gain some performance improvements and support both AM and SSB signals. His build is based on a generic design available here, along with a couple modifications by Ryan Flowers, and of course his own experimentation to get things working properly.

The device is controlled by an Arduino, which changes the frequency via an Si6351 oscillator depending on encoder input. Visual frequency feedback is provided by a small OLED display, and the assembly is encased in a very cool 3D-printed enclosure—or rather ‘enclosures’ as two boxes separate the digital and radio/audio circuits. 

It’s a simple configuration and the result, as shown in the video below, is a very clean sound! 

Robotic arms can be interesting, as are robots that roll around—especially on a semi-exotic Mecanum wheel setup. Dejan Nedelkovski’s latest How To Mechatronics build, however, combines both into one package.

This project actually starts out in a previous post, where he constructs the moving base with Mecanum wheels, enabling it to slide and rotate in any direction.

In this final(?) stage, he adds a five-axis robot arm mounted on top of its boxy frame, or six-axis if you count the gripper. Either way, the arm uses a total of six servos for actuation, and the base of the bot travels around under the power of four stepper motors. Each motor is controlled by an Arduino Mega, using a custom shield, allowing repeatable movements in any direction. These can be stored and replayed via the robot’s custom Android app as desired.

The future envisioned in the original Star Trek included, among other things, a shipboard sickbay with electronic monitors strangely reminiscent of the machines that medical personnel use today. To recreate a functional mini-replica of these displays, YouTuber Xtronical turned to a 2.8” TFT screen, a breadboard, and an Arduino Nano—noting that an Uno would also work.

The LCD display nails the look of Dr. McCoy’s device, and heartbeat sound can be played along with an onscreen flashing “PULSE” circle. A MAX30100 pulse/oximeter sensor and a temperature sensor take body readings, while a second DS18B20 is implemented to read ambient conditions for increased accuracy. 

It’s a fun Trekkie project, and Xtronical plans to elaborate on how it was made in future videos. 

A build of a working original Star Trek display with real sampled heart beat sound. Uses various sensors to get the readings from your body (via just your fingers) and displays them in the style of the 60’s sick bay screen. This bare “Bones” system could be built into a model unit or even a replica Tricorder.

There are many reasons why one would want to measure voltage and current in a project, some applications requiring one to measure mains and even three-phase voltage to analyze the characteristics of a device under test, or in a production environment. This led [Michael Klopfer] at the University of California, Irvine along with a group of students to develop a fully isolated board to analyze both single and three-phase mains systems.

Each of these boards consists out of two sections: one is the high-voltage side, with the single phase board using the Analog Devices ADE7953 and the three-phase board the ADE9708. The other side is the low-voltage, isolated side to which the microcontroller or equivalent connects to using either SPI or I2C. Each board type comes in either SPI or I2C flavor.

Each board can be used to measure line voltage and current, and the Analog Devices IC calculates active, reactive, and apparent energy, as well as instantaneous RMS voltage and current. All of this data can then be read out using the provided software for the Arduino platform.

The goal of this project is to make it easy for anyone to reproduce their efforts, with board schematics (in Eagle format) and the aforementioned software libraries provided. Here it is somewhat unfortunate that the documentation can be somewhat incomplete, with basic information such as input and measurement ranges missing. Hopefully this will improve over the coming months as it does seem like a genuinely useful project for the community.

We’ve covered the work coming out of [Michael]’s lab before, including this great rundown on Lattice FPGAs. They’re doing machine vision, work on RISC-Vchips, and more. A stroll through the lab’s GitHub is worth your time.

Security cameras are a great way to deter theft and vandalism, but what if the camera is out of WiFi range, or otherwise would need long cables to transmit pictures? As explained here, Tegwyn Twmffat has an interesting solution–taking advantage of neural network processing to recognize moving objects, along with a LoRa connection to sound the alarm when there is a potential problem.

Images are captured by a Raspberry Pi and camera, then processed with the help of an Intel Movidius Neural Compute Stick for identification. If it’s something of interest—a human, for example—a relatively small amount of data is transmitted to a MKR WAN 1300 base station, beeping faster and faster as the person approaches. 

As seen in the video below, it’s able to properly ignore the ‘test dog,’ while it beeps away when a person approaches! 

If Elon Musk was to design a soapbox car, the prototype might look something like this by David Traum.

Traum’s project is powered by a 500W motor which is fed by a pair of 12V batteries and a 40 W solar cell, allowing it to attain a top speed of 35 km/h and a range of 10 to 15km. Although that might not sound like a huge number, it looks pretty fast at the end of the video below!

But that’s not all. The vehicle features a rather unique control system, with front wheel steering actuated by a stepper and cable assembly. An Arduino Mega is the brains of the operation, while user input is via a small touchscreen, a joystick, and even a steering wheel (equipped with an Uno, a 9V battery, radio module, and gyro sensor) that can work wirelessly as needed—perhaps to park remotely, or simply as a gigantic RC car

The clip here is in German, but you can read more in this English-translated article.

Imagine if you had whiskers. Obviously, this would make you something of an oddity in today’s society. On the other hand, you’d be able to sense nearby objects via the transmission of force through these hair structures.

In order to explore this concept, Chris Hill has created a whisker assembly for sensory augmentation, substituting flex sensors for the stiff hairs that we as humans don’t possess. The sensors—four are used here—vary resistance when bent, furnishing information about their status to the Arduino Uno that controls the wearable device. Forehead-mounted vibratory motors are pulsed via PWM outputs in response, allowing the user to feel what’s going on in the surrounding environment.

If this looks familiar, Hill is quick to credit Nicholas Gonyea’s Whisker Sensory Extension Wearable as the basis for this project. He hopes his take on things improves the original, making it lighter, more cost-effective, and easier to construct. 

The purpose of this project was to focus on the creation of novel, computationally-enriched “sensory extensions” that allow for augmented-sensing of the natural world. My major effort with this project was devoted to the fabrication and implementation of sensory augmentations that will extend a sense through sensors and respond with a tactile output for the user. The intent is to enable anyone to fabricate their own sensory extensions, and thusly map intrinsically human/animal senses onto hardware. Effectively extending our senses in new and exciting ways that will lead to a better understanding of how our brain is able to adapt to new external senses.