Spherical Quadruped Arduino Robot

[Greg06] started learning electronics the same way most of us did: buy a few kits, read a few tutorials, and try your hardest to put a few things together. Sound familiar? After a while, you noticed your skills started increasing, and your comfort level with different projects improved as well. Eventually, you try your hand at making your own custom projects and publishing your own tutorials.

Few are lucky to have a first-project as elaborate as [Greg06’s] quadruped robot. We don’t know about you, but for some of us, we were satisfied with blinking two LEDs instead of just one.

[Greg06’s] robot has a quadruped based, housed within a 3D printed spherical body. The legs are retractable and are actuated by tiny servo motors inside the body. [Greg06] even included an ultrasonic distance sensor for the obstacle avoidance mechanism. Honestly, if it weren’t for the ultrasonic distance sensor protruding from the spherical body, you might think that the entire robot was just a little Wiffle ball. This reminds us of another design we’ve seen before.

If that weren’t enough, the spherical head can rotate, widening the range of the ultrasonic distance sensor and obstacle avoidance mechanism. This is accomplished by attaching another servo motor to the head.

Pretty neat design if you ask us. Definitely one of the coolest quadrupeds we’ve seen.

Defense Department Funds Wearables To Detect COVID-19

As many countries across the globe begin loosening their stay-at-home orders, we’re seeing government agencies and large companies prepare for the lasting effects of the pandemic. A recent solicitation from the United States Department of Defense (DoD) indicates they are investing $25 million into wearable devices that can detect early signs of COVID-19.

Based on a few details from the request for project proposals, it looks like the DoD is targeting mostly companies in this particular solicitation, but have left the door open for academic institutions as well. That makes intuitive sense. Companies can generally operate at a faster pace than most academic research labs. Given the urgency of the matter, faster turnarounds in technological development are imperative. Nonetheless, we have seen quite a bit of important COVID-19 work coming from academic research labs and we imagine that battling this pandemic will take all the brilliant minds we can muster together.

It’s good to see the DoD join the fight in what could be a lengthy battle with the coronavirus.

Please feel free to read through the request for project proposals for more details.

PCB Jewelry Never Looked So Good

[Gautchh] wanted to make something nice for his girlfriend. Being the DIY enthusiast he is, he thought a hand-made gift would resonate with her better than something he could pick up from the store. Enter NeckLight, a glow in the dark PCB necklace. He was first inspired by another project he ran across on Instructables, then decided to put his own little spin on the design. It’s cool how that works. Interestingly enough, it was his first time using Fusion 360, but you probably wouldn’t know that if you took a look at the results.

Aside from soldering, the trickiest part of this project was trying to get the LED intensities just right. [Gautchh] found the best way to do this was experimentally by testing each LED color with a series of resistors. He wanted to ensure he could get the color intensity and the LED current just right. Finally, with a touch of acetone, he was done (though he might want to try some alternatives to acetone next time).

[Gautchh] also thinks that this project would be a really nice way for beginners to learn surface mount (SMD) soldering. We’ve seen a few cool SMD LED projects before. Who could forget those competitive soldering challenges over at DEF CON?

Anyway. Thanks, [Gautchh]. We hope your girlfriend, and your dog, enjoyed their gifts.

DIY Neuralyzer From Scrap Parts

Cosplay and prop making are near and dear to our hearts here at Hackaday. That’s why whenever we see sci-fi tech brought to life, we can’t help but pay close attention. Enter [How to make’s] DIY Neuralyzer, from the Men-in-Black franchise. Unfortunately, this won’t wipe your memories as the real-life Neuralyzer would, but it will make for a cool prop at your next cosplay event.

What makes this project worth sharing is its use of very simple home tools and a bit of scrap metal, some PVC, a single LED, a switch, and maybe a few more miscellaneous bits. The base of the design is composed of two pieces of hollow, rod-shaped scrap metal and a single spring that mechanizes the entire setup.

The video is a few months old at this point. It took a recent post on Reddit to send this across our feed, but we’re glad we came across it.

Great project [How to make]! May we suggest a few more LEDs?

Continue reading “DIY Neuralyzer From Scrap Parts”

Purdue Meta-AR-App Allows Instructors And Students To Build Their Own AR Learning Content

Augmented reality (AR) in the classroom has garnered a bit of interest over the years, but given the increased need for remote and virtual learning these days, it might be worth taking a closer look at what AR can offer. Purdue University’s C Design Lab thinks they’ve found a solution in their Meta-AR platform. The program allows an instructor to monitor each student’s work in real-time without being in the same classroom as the student. Not only that, but the platform allows students to collaborate in real-time with each other giving each other tips and feedback while also being able to interact with each other’s work, no matter where they may be physically located.

What we find really cool is the real-time feedback the software provides to the students. The system can sense what the students are touching and can help students in their given task, providing real-time feedback on what they are doing, how things should fit together, and what type of outcomes the students can expect given their trajectory. It also appears the system isn’t limited to AR markers but provides a very expansive toolbox for instructors and students to build on. C Design Lab is doing quite a bit of user feedback studies, continually incorporating input from students to further the platform. That’s definitely critical to ensuring the system is user-friendly.

We can easily see how something like this might scale to an industrial setting for training people how to use complex machinery, to a medical school to help prepare students to do surgery or to help develop molecular diagnostics tools. Check out the other learning tools C Design Lab is developing.

A Smart Bandage For Monitoring Chronic Wounds

Here at Hackaday, we’re always enthralled by cool biohacks and sensor development that enable us to better study and analyze the human body. We often find ourselves perusing Google Scholar and PubMed to find the coolest projects even if it means going back in time a year or two. It was one of those scholarly excursions that brought us to this nifty smart bandage for monitoring wound healing by the engineers of FlexiLab at Purdue University. The device uses an omniphobic (hydrophobic and oleophobic) paper-based substrate coupled with an onboard impedance analyzer (AD5933), an electrochemical sensor (the same type of sensor in glucometers) for measuring uric acid and pH (LMP91000), and a 2.4 GHz antenna for wirelessly transmitting the data (nRF24L01). All this is programmed with an Arduino Nano. They even released their source code.

To detect uric acid, they used the enzyme uricase, which is very specific to uric acid and exhibits low cross-reactivity with other compounds. They drop cast uric acid onto a silver/silver chloride electrode printed on the omniphobic paper. Similarly, to detect pH, they drop cast a pH-responsive polymer called polyaniline emeraldine salt (PANI-ES) between two separate silver/silver chloride electrodes. All that was left was to attach the electrodes to the LMP91000, do a bit of programming, and there they were with their own electrochemical sensor. The impedance analyzer was a bit simpler to develop, simply attaching un-modified electrodes to the AD5933 and placing the electrodes on the wound.

The authors noted that the device uses a much simpler manufacturing process compared to smart bandages published by other academics, being compatible with large-scale manufacturing techniques such as roll-to-roll printing. Overcoming manufacturing hurdles is a critical step in getting your idea into the hands of consumers. Though they have a long way to go, FlexiLab appears to be on the right track. We’ll check back in every so often to see what they’re up to.

Until then, take a look at some other electric bandage projects on Hackaday or even make your own electrochemical sensor.

A Backpack That Measures Your Heart Rate

It’s interesting to see the different form-factors that people utilize for their portable biometric sensors. We’re seeing heart rate monitors and other biometric sensors integrated into watches, earbuds, headbands, sports bras, and all sorts of other garments and accessories. [Gabi] took an intriguing approach, integrating an electrocardiogram (ECG) into a backpack. This type of heart rate project is pretty popular here on Hackaday, so it was great running across [Gabi’s] design during our daily perusing for the new and exciting.

[Gabi] used an Adafruit FLORA, a BLE module, an ECG sensor from Bitalino, a few other ancillary components, and, of course, a backpack. We appreciate that she walked us through the list of stumblingblocks she came across and how she got around them. So much of the time in our excitement to share our projects we remove the gory details and only present the finished project when really, we learn most from all the things that didn’t work more so than the things that did. Finally, [Gabi] walks through the intricacies of the threading and the particular placement of the snap connectors to attach the circuit to the ECG electrodes. Things get pretty tricky, but luckily [Gabi] documents her project pretty meticulously with schematics, pictures, and early notice of pitfalls.

[Gabi] made sure to remind her readers that this is a prototype, not a medical device. She also brought up electrical safety. Biometric devices such as ECGs need to include a strict set of isolation circuits to prevent potential harm to the user. Fortunately, there are a few well-characterized methods to accomplish this.

So thanks for a really cool project, [Gabi], and to our readers, why not enjoy some of our other ECG projects while you’re at it?