Day: July 22, 2020

Let’s Take A Closer Look At This Robotic Airship

July 22, 2020 by 30 Comments

It’s not a balloon, however shiny its exterior may seem. This miniature indoor robotic airship created by the University of Auckland mechanical engineering research group [New Dexterity] is an asymmetric system experimenting with the possibilities of an open-source helium-based airship.

Why a helium airship, as opposed to a fixed wing aircraft? The group wanted to experiment with the advantages of lighter-than-air (LTA) travel, namely the higher mobility and looser path planning constraints. Furthermore, LTA airships have a less obstructed field of vision and fewer locomotion issues. While unmanned aerial vehicles (UAV) may be capable of hovering in one place, their lift is generated by rotor thrust, which drains their batteries quickly in the order of minutes. LTA airships can hover for longer periods of time.

The design was created for educational and research purposes, focusing on the financial feasibility of manufacturing the platform, the environmental impact of the materials, and the helium loss through the balloon-like envelope. By measuring these parameters, the researchers are able to study the effects of circumstances such as the cost of indoor commercial balloons and the mechanical properties of balloon materials.

The airship gondola was designed and 3D printed in a modular fashion, then attached to the envelope with Velcro. The placement with respect to the horizontal symmetry of the gondola was done for flight stability, with several configurations tested for the side rotor angle.

The group open-sourced their CAD files and ROS interface for controlling the airship. They primarily use off-the-shelf components such as Raspberry Pi boards, propellers, a DC single brushed motor driver carrier, and LiPo batteries for a total cost of $90 for the platform, with an addition $20 for the balloon and initial helium filling. The price is comparable to the cost of indoor blimps like the Blimpduino 2.0.

You can check out the completed airship below, where the team demonstrates its path following capabilities based on a carrot chasing path finding algorithm. And if you’re interested in learning more about the gotchas of building lighter-than-air vehicles, check out [Sophi Kravitz’s] blimp talk from Hackaday Belgrade.

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DIY Stress Meter

July 22, 2020 by 28 Comments

Stress monitoring has always been a tricky business. As it turns out, there is a somewhat reliable way of monitoring stress by measuring how much cortisol, the so-called “stress hormone,” the human body produces. With that in mind, bioengineering researchers at the University of Texas at Dallas decided to make CortiWatch, a wearable device for continuously monitoring cortisol excreted in sweat, as a sort of DIY stress meter.

They made their own potentiostat, a device for measure small amounts of current produced by electrochemical reactions, similar to the glucometer. We’ve talked about these types of measurements before. Simply put, the potentiostat contains a voltage reference generator which biases the sensing electrodes at a preset potential. The voltage bias causes local electrochemical reactions at the sensing electrodes (WE in the image above), stimulating electron flow which is then measured by a transimpedance amplifier or “current-to-voltage” converter. The signal is then analyzed by an onboard analog-to-digital converter. Simply put, the more cortisol in the system, the higher the transimpedance amplifier voltage.

To validate their system a bit more thoroughly than simple benchtop studies, the researchers did some “real-life” testing. A volunteer wore the CortiWatch for 9 hours. The researchers found a consistent decrease in cortisol levels throughout the day and were able to verify these measurements with another independent test. Seems reasonable, however, it’s not quite clear to us what cortisol levels they were expecting to measure during the testing period. We do admit that it takes quite a bit of calibration to get these systems working in real-life settings, so maybe this is a start. We’ll see where they go from here.

Maybe the CortiWatch can finally give us a proper lie detector. We’ll let you be the judge.

Versatile Energy Meter Has Multiple Functions

July 22, 2020 by 10 Comments

If you are dealing with solar or battery power, you might want to have one of these little energy meters built by [Open Green Energy] around. The Arduino-based instrument measures DC voltage, current, power, energy, capacity, and temperature. The range is only up to 26 volts and 3.2 amps, but you could extend that with some external circuitry.

Of course, measuring a voltage with the Arduino is old hat. But the addition of a INA219 current sensor provides voltage, current, and power measurements in a single module that talks I2C back to the host computer.

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Bringing The Pi Camera Into Focus With LEGO

July 22, 2020 by 6 Comments

Ever since the high-quality camera for the Raspberry Pi was released a few months back it has been the center of attention for many hacks. In this quick build [Martin Mander] shows us how to make a servo-powered focusing mechanism entirely from LEGO.

The inspiration for this project came to him while he was working on his 1979 Merlin Pi Camera and found that setting the focus just right is vital in order to get good quality pictures. So he set himself the goal to build a mechanism that allows him to focus the camera precisely and remotely.

It is the plethora of LEGO-compatible parts that are available off-the-shelf that make such a project possible without the use of any 3D printed components. He not only found a LEGO-compatible continuous rotating servo but also a LEGO-compatible case for the Pi, and a LEGO cogwheel which almost fits exactly onto the camera lens. He also added a tripod mount to the case that allows him to set up the camera anywhere. The camera and focussing mechanism are controlled with a custom GUI based on guizero Python 3 library and the camera can be accessed remotely via VNCViewer.

If you prefer 3D printing over LEGO there are also other stylish Raspi HQ camera builds.

Video after the break.

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CBS Announces Functional Tricorder Replica For 2021

July 22, 2020 by 61 Comments

It’s taken 54 years, but soon, you’ll finally be able to buy a fully-functional version of the tricorder from Star Trek. Announced on the official website for the legendary sci-fi franchise, the replica will be built by The Wand Company, who’ve previously produced a number of high-quality official Star Trek props as well as replicas for Doctor Who and the Fallout game series.

Admittedly, we’re not sure what a “fully-functional tricorder” actually is, mainly because the various on-screen functions of the device were largely driven by whatever bind Kirk and Spock managed to find themselves in that week. But the announcement mentions the ability to scan radio frequencies, pull in dynamic data from environmental sensors, and record audio. The teaser video after the break doesn’t give us any more concrete information than the announcement, but it does seem to confirm that we’ll be viewing said data on the device’s iconic flip-up display.

Now as the regular Hackaday reader knows, fans have been building extremely impressive “functional” tricorders for some time now. Unlike the sleek 24th century versions seen in Star Trek: The Next Generation, the original tricorder prop was rather clunky and offers plenty of internal volume for modern goodies. Cramming a Raspberry Pi, LCD, and a bunch of sensors into an inert replica is a relatively approachable project. So it will be interesting to see how the official version stacks up to what’s already been done by intrepid hackers and makers.

The official tricorder won’t be available until summer of 2021, but you can sign up to be notified when it’s your turn to beam one up. While the $250 USD sticker price might keep the more casual Trekkers at bay, it’s actually a bit cheaper than we would have assumed given the amount of time and money we’ve seen fans put into their own builds.

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Jan Czochralski And The Silicon Revolution

July 22, 2020 by 39 Comments

If you were to travel back in time to the turn of the previous century and try to convince the average person that the grains of sand on just about any beach would be the basis of an industry worth hundreds of billions of dollars within 100 years, they’d probably have thought you were crazy. Aside from being coarse, rough, and irritating, sand is everywhere, and convincing anyone of its value would be a hard sell, unless your interlocutor was a real estate visionary with an appreciation of the future value of seaside property and a lot of patience.

Fast forward to our time, and we all know the value of the material that comes from common quartz sand: silicon, specifically the ultra-purified crystals of silicon that end up as the wafers we depend on to build the circuitry of life. The trip from beach to chip foundry is a long and non-obvious one which would not have been possible without the insights of an undistinguished Polish student and one-time druggist who discovered the process that made the Information Age possible: Jan Czochralski.

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Robot, Sudo Fold My Laundry

July 22, 2020 by 11 Comments

[Ty Palowski] doesn’t like folding his many shirts. He saw one of those boards on TV that supposedly simplifies folding, but it does require you to manually move the board. That just won’t do, so [Ty] motorized it to create a shirt folding robot.

The board idea is nothing new, and probably many people wouldn’t mind the simple operation required, but what else are you going to do with your 3D printer but make motor mounts for a shirt folding machine? The folding board is, of course, too big for 3D printing so he made that part out of cardboard at first and then what looks like foam board.

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