Maybe One Of The Most Adorable Obstacle Avoiding Robots You’ve Seen

We’re all pretty well-acquainted with the obstacle avoiding robot. These little inventions use a proximity sensor to detect an object in front of the robot, then circumvent the object accordingly. Brown Dog Gadgets’ little robot really caught our eye, mostly because it’s kind of cute.

This little robot combines a few LEGO pieces, Arduino, and Brown Dog Gadgets’ own in-house invention, Crazy Circuits. The LEGO pieces make up the body of the robot, craftily enclosing a small portable battery pack used to power the bot. Brown Dog Gadgets uses another home-grown design, their robotics controller board, breaking out a few GPIO pins of an Arduino-compatible microcontroller into LEGO-compatible connections. This makes it easy to interface two of our favorite DIY STEM tools using a solderless connection.

Add a few LEGO wheels and a caster for pivoting and you’ve got a pretty simple, little robot. Fortunately, Brown Dog Gadgets was very thorough in their write-up, so head on over to their Instructable for all the details.

In the meantime, we’ve got a rich history of obstacle-avoiding robots here on Hackaday. Take a look around.

Detect COVID-19 Symptoms Using Wearable Device And AI

A new study from West Virginia University (WVU) Rockefeller Neuroscience Institute (RNI) uses a wearable device and artificial intelligence (AI) to predict COVID-19 up to 3 days before symptoms occur. The study has been an impressive undertaking involving over 1000 health care workers and frontline workers in hospitals across New York, Philadelphia, Nashville, and other critical COVID-19 hotspots.

The implementation of the digital health platform uses a custom smartphone application coupled with an Ōura smart ring to monitor biometric signals such as respiration and temperature. The platform also assesses psychological, cognitive, and behavioral data through surveys administered through a smartphone application.

We know that wearables tend to suffer from a lack of accuracy, particularly during activity. However, the Ōura ring appears to take measurements while the user is very still, especially during sleep. This presents an advantage as the accuracy of wearable devices greatly improves when the user isn’t moving. RNI noted that the Ōura ring has been the most accurate device they have tested.

Given some of the early warning signals for COVID-19 are fever and respiratory distress, it would make sense that a device able to measure respiration and temperature could be used as an early detector of COVID-19. In fact, we’ve seen a few wearable device companies attempt much of what RNI is doing as well as a few DIY attempts. RNI’s study has probably been the most thorough work released so far, but we’re sure that many more are upcoming.

The initial phase of the study was deployed among healthcare and frontline workers but is now open to the general public. Meanwhile the National Basketball Association (NBA) is coordinating its re-opening efforts using Ōura’s technology.

We hope to see more results emerge from RNI’s very important work. Until then, stay safe Hackaday.

Hack Together Your Own Bat Signal

Bats use echolocation to see objects in front of them. They emit an ultrasonic pulse around 20 kHz (and up to 100 kHz) and then sense the pulses as they reflect off an object and back to the bat. It’s the same type of mechanism used by ultrasonic proximity sensors for object-avoidance. Humans (except perhaps the very young ones) can’t hear the ultrasonic pulses since the frequency is too high, but an inexpensive microphone in a simple bat detector could. As it turns out bat detectors are available off the shelf, but where’s the fun in that? So, like any good hacker, [WilkoL] decided to build his own.

[WilkoL’s] design is composed primarily of an electret microphone, microphone preamplifier, CD4040 binary counter, LM386 audio amplifier, and a speaker. Audio signals are analog and their amplitudes vary based on how close the sound is to the microphone. [WilkoL] wanted to pick up bat sounds as far away as possible, so he cranked up the gain of the microphone preamplifier by quite a bit, essentially railing the amplifiers. Since he mostly cares about the frequency of the sound and not the amplitude, he wasn’t concerned about saturating the transistor output.

The CD4040 then divides the signal by a factor of 16, generating an output signal within the audible frequency range of the human ear. A bat signal of 20 kHz divides down to 1.25 kHz and a bat signal of up to 100 kHz divides down to 6.25 kHz.

He was able to test his bat detector with an ultrasonic range finder and by the noise generated from jingling his keychain (apparently there are some pretty non-audible high-frequency components from jingling keys). He hasn’t yet been able to get a recording of his device picking up bats. It has detected bats on a number of occasions, but he was a bit too late to get it on video.

Anyway, we’re definitely looking forward to seeing the bat detector in action! Who knows, maybe he’ll find Batman.

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A Wearable That Jives To The Beat Of Your Heart

We’re always searching for the coolest biohacking projects all over the web, so imagine our excitement when we ran across [marcvila333’s] wearable biometric monitor on Instructables. This was a combined effort between [Marc Vila], [Guillermo Stauffacher], and [Pau Carcellé] as they were wrapping up the semester at their university. Their goal was to develop an integrated device that could modulate the wearer’s heart, and subsequently their mood and stress levels, using music.

Their device includes an LCD screen for user feedback, buttons for user input, an MP3 module, and a heart rate sensor module. The user can measure their heart rate and use the buttons to select the type of music they desire based on whether they would like to decrease or increase their heart rate. The science behind this phenomenon is still unknown, but the general sense is that different music can trigger different chemical signals in your brain, subsequently affecting your mood and other subtle physiological effects. I guess you can say that we tend to jive to the beat of our music.

It would be really cool to see their device automatically change the song to either lower or raise the user’s heart rate, making them calmer or more engaged. Maybe connect it to your tv? Currently, the user has to manually adjust the music, which might be a bit more inconvenient and could possibly lead to the placebo effect.

Either way; Cool project, team. Thanks for sharing!

Your Own Electronic Drum Kit

[Jake_Of_All_Trades] wanted to take up a new drumming hobby, but he didn’t want to punish his neighbors in the process. He started considering an electric drum kit which would allow him to practice silently but still get some semblance of the real drumming experience.

Unfortunately, electric drum kits are pretty expensive compared to their acoustic counterparts, so buying an electric kit was a bit out of the question. So, like any good hacker, he decided to make his own.

He found a pretty cheap acoustic drum kit on Craigslist and decided to convert it to electric. He thought this would be a perfect opportunity to learn more about electric drum kits in general and would allow him to do as much tweaking as he wanted to in order to personalize his experience. He also figured this would be a great way to get the best of both worlds. He could get an electric kit to practice whenever he wanted without disturbing neighbors and he could easily convert back to acoustic when needed.

First, he had to do a bit of restorative work with the cheap acoustic kit he found on eBay since it was pretty worn. Then, he decided to convert the drum heads to electric using two-ply mesh drum heads made from heavy-duty fiberglass screen mesh. The fiberglass screen mesh was cheap and easy to replace in the event he needed to make repairs. He added drum and cymbal triggers with his own DIY mechanism using a piezoelectric element, similar to another hack we’ve seen. These little sensors are great for converting mechanical to electrical energy and can feed directly into a GPIO to detect when the drum or cymbal was struck. The electrical signal is then interpreted by an on-board signal processing module.

All he needed were some headphones or a small amplifier and he was good to go! Cool hack [Jake_Of_All_Trades]!

While you’re here, check out some of our best DIY musical projects over the years.

DIY Baby MIT Cheetah Robot

3D printers have become a staple in most makerspaces these days, enabling hackers to rapidly produce simple mechanical prototypes without the need for a dedicated machine shop. We’ve seen many creative 3D designs here on Hackaday and [jegatheesan.soundarapandian’s] Baby MIT Cheetah Robot is no exception. You’ve undoubtedly seen MIT’s cheetah robot. Well, [jegatheesan’s] hack takes a personal spin on the cheetah robot and his results are pretty cool.

The body of the robot is 3D printed making it easy to customize the design and replace broken parts as you go. The legs are designed in a five-bar linkage with two servo motors controlling each of the four legs. An additional servo motor is used to rotate an HC-SR04, a popular ultrasonic distance sensor, used in the autonomous mode’s obstacle avoidance mechanism. The robot can also be controlled over Bluetooth using an app [jegatheesan] developed in MIT App Inventor.

Overall, the mechanics could use a bit of work — [jegatheesan’s] baby cheetah probably won’t outpace MIT’s robot any time soon — but it’s a cool hack and we’re looking forward to a version 3. Maybe the cheetah would make a cool companion bot?

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Digi-Key Hacks UV Into Conveyor Line To Protect Warehouse Staff

No doubt that every hacker has already heard of Digi-Key, the electronic component distributor that makes it just as possible to order one of something as it is to order a thousand of it. As an essential business, Digi-Key has been open during the duration of the lockdown since they support critical manufacturing services for virtually every industry on the planet including the medical industry.

Ensuring their workforce stays healthy is key to remaining open and as part of their efforts they hacked together a nice addition to their sanitation regime. They use around 8,000 plastic totes to transport components around the distribution center and devised a way to sanitize tote coming in from the receiving area using a UV light tunnel. From their sanitation plan we can see this is in addition to the fogging system (likely a vaporized hydrogen peroxide system) used to regularly sanitize the totes passing throughout the warehouse.

They developed a UV light tunnel that wraps around the conveyor rollers. The design includes a sensor and a timer to control when and how long the UV lights are on. The totes are a frequent touch point for employees, and running incoming shipments through the UV light tunnel helps decrease the chance of exposure.

Thinking of using UV as a sanitation tool? Make sure you do your research on the wavelengths you need and vet the source of critical components. [Voja] ran into UV lamps that were anything but germicidal.