DIY Geiger Counter Is Sure To Generate Clicks

August 19, 2019 by 19 Comments

On the outside, a Geiger counter seems like a complicated thing. And you might think a device that detects a dangerous, mostly invisible threat like radiation should be complicated. But they’re actually pretty simple. The Geiger-Muller tube does most of the work, which boils down to detecting brief moments of conductivity caused by chain reactions of charged particles in radioactive materials.

[Prabhat_] wanted to build a unique-looking Geiger counter, and we’d say that this slick, Star Trek-esque result succeeds. A well-organized display shows the effective dose rate, counts per minute, and cumulative dose, which can be displayed in either microsieverts or millirems. We dig the 3D printed case design, because we like to see form follow function.

The counter is powered by an 18650 cell that’s DC-to-DC boosted to 400+ volts. A NodeMCU processes the signal coming in from the G-M tube and expresses it in both clicks and LED blinks, both of which can be toggled on or off from the home screen. The alert threshold can be customized in the settings, which means the point at which green changes to red.

Click-click-click past the break for [prabhat_]’s great walk-through video, where he tests it with uranium ore and a thoriated gas lantern mantle.

If you want to take the opposite approach and get to clicking ASAP, well, fire up your hot glue gun and dump out your scrap bin.

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Life At JPL Hack Chat

August 19, 2019 by 6 Comments

Join us on Wednesday, August 21st at noon Pacific for the Life at JPL Hack Chat with Arko!

There’s a reason why people use “rocket science” as a metaphor for things that are hard to do. Getting stuff from here to there when there is a billion miles away and across a hostile environment of freezing cold, searing heat, and pelting radiation isn’t something that’s easily accomplished. It takes a dedicated team of scientists and engineers working on machines that can reach out into the vastness of space and work flawlessly the whole time, and as much practice and testing as an Earth-based simulation can provide.

Arko, also known as Ara Kourchians, is a Robotics Electrical Engineer at the Jet Propulsion Laboratory, one of NASA’s research and development centers. Nestled at the outskirts of Pasadena against the flanks of the San Gabriel Mountains, JPL is the birthplace of the nation’s first satellite as well as the first successful interplanetary probe. They build the robots that explore the solar system and beyond for us; Arko gets to work on those space robots every day, and that might just be the coolest job in the world.

Join us on the Hack Chat to get your chance to ask all those burning questions you have about working at JPL. What’s it like to build hardware that will leave this world and travel to another? Get the inside story on how NASA designs and tests systems for space travel. And perhaps get a glimpse at what being a rocket scientist is all about.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 21 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Apollo’s PLSS And The Science Of Keeping Humans Alive In Space

August 19, 2019 by 13 Comments

Ever since humans came up with the bright idea to explore parts of the Earth which were significantly less hospitable to human life than the plains of Africa where humankind evolved, there’s been a constant pressure to better protect ourselves against the elements to keep our bodies comfortable. Those first tests of a new frontier required little more than a warm set of clothes. Over the course of millennia, challenging those frontiers became more and more difficult. In the modern age we set our sights on altitude and space, where a warm set of clothes won’t do much to protect you.

With the launch of Sputnik in 1957 and the heating up of the space race between the US and USSR, many firsts had to be accomplished with minimal time for testing and refinement. From developing 1945’s then state-of-the-art V-2 sounding rockets into something capable of launching people to the moon and beyond, to finding out what would be required to keep people alive in Earth orbit and on the Moon. Let’s take a look at what was required to make this technological marvel happen, and develop the Portable Life Support System — an essential component of those space suits that kept astronauts so comfortable they were able to crack jokes while standing on the surface of the Moon.

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Fail Of The Week: Spinning The Pripyat Ferris Wheel

August 7, 2019 by 67 Comments

This multifaceted fail comes to us straight from the Chernobyl Exclusion Zone, where a group of friends apparently decided that a fun weekend project would be trying to turn over the iconic ferris wheel in the Pripyat Amusement Park. The [Kreosan] crew documented their admittedly very creative attempt at suicide in the video after the break, but we can save you some time by telling you right up front that the decades-old ferris wheel never actually rotates more than a few degrees. Though that’s hardly the key failure of this endeavour.

Even if you don’t understand anything they’re saying (we certainly don’t), it’s not too hard to follow along with this harebrained scheme.

Under cover of darkness, the troupe gains access to the mechanisms below the towering Soviet-era ride, and removes the brake unit mounted next to the motor. With the wheel now free spinning, the team is elated to see the mechanical advantage is such that spinning the shaft by hand is enough to cause a very slight rotation of the pulley and cables attached to the wheel.

Realizing they need more speed, the group then spends the rest of the night and apparently a good deal of the following day attempting to spin the mechanism using the rear wheel of one of their electric bicycles. But a rubber wheel held by hand against a rusty shaft, rather unsurprisingly, turns out to be a fairly poor mechanical linkage. They get a couple partial rotations on the pulleys, but still no serious movement.

One of the guys was working on the next phase of the inexplicably misguided plan, removing some heavy counterweights hanging under the ferris wheel, when a young woman shows up with a dosimeter and starts taking some measurements. Eventually, one of these moonlighting ferris wheel engineers uses the meter to observe the elevated radiation levels of the dirt and rust accumulated on his bare hands. This swiftly brings the operation to a close, and they all ride off on their bikes.

This was, without question, a monumentally stupid thing to do. Even if this was just a run-of-the-mill ferris wheel that had been abandoned and exposed to the elements for over thirty years, climbing on the thing and trying to get it to spin would be dangerous. But when you combine that with the fact it’s common knowledge to those who explore the Exclusion Zone that there are parts of the ferris wheel still emitting radiation at hundreds of times the normal background dose, this misadventure is a strong contender for the 2019 Darwin Award.

We’re lucky the remnants of Chernobyl’s number four reactor are locked away inside the Chernobyl New Safe Confinement, or else some up-and-coming Internet celebrity might try to get in there and spin up the turbines for a laugh. We’ve seen some pretty crazy stunts from [Kreosan], and we’d like to see more. So please, stay safe(r) guys!

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DIY Scintillation Detector Is Mighty Sensitive

July 19, 2019 by 24 Comments

Geiger counters are a popular hacker project, and may yet prove useful if and when the nuclear apocalypse comes to pass. They’re not the only technology out there for detecting radiation however. Scintillation detectors are an alternative method of getting the job done, and [Alex Lungu] has built one of his own.

Scintillation detectors have several benefits over the more common Geiger-Muller counter. They work by employing crystals which emit light, or scintillate, in the presence of ionizing radiation. This light is then passed to a photomultiplier tube, which emits a cascade of electrons in response. This signal represents the level of radioactivity detected. They can be much more sensitive to small amounts of radiation, and are more sensitive to gamma radiation than Geiger-Muller tubes. However, they’re typically considered harder to use and more expensive to build.

[Alex]’s build uses a 2-inch sodium iodide scintillator, in combination with a cheap photomultiplier tube he scored at a flea market for a song. [Jim Williams]’s High Voltage, Low Noise power supply is used to run the tube, and it’s all wrapped up in a tidy 3D printed enclosure. Output is via BNC connectors on the rear of the device.

Testing shows that the design works, and is significantly more sensitive than [Alex]’s Geiger-Muller counter, as expected. If you’re interested in measuring small amounts of radiation accurately, this could be the build for you. We’ve seen this technology used to do gamma ray spectroscopy too.

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Exploring The Raspberry Pi 4 USB-C Issue In-Depth

July 16, 2019 by 117 Comments

It would be fair to say that the Raspberry Pi team hasn’t been without its share of hardware issues, with the Raspberry Pi 2 being camera shy, the Raspberry Pi PoE HAT suffering from a rather embarrassing USB power issue, and now the all-new Raspberry Pi 4 is the first to have USB-C power delivery, but it doesn’t do USB-C very well unless you go for a ‘dumb’ cable.

Join me below for a brief recap of those previous issues, and an in-depth summary of USB-C, the differences between regular and electronically marked (e-marked) cables, and why detection logic might be making your brand-new Raspberry Pi 4 look like an analogue set of headphones to the power delivery hardware.

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It’s NICER In Orbit

July 9, 2019 by 1 Comment

Given the sheer volume of science going on as the International Space Station circles above our heads every 90 minutes or so, it would be hard for any one experiment to stand out. ISS expeditions conduct experiments on everything from space medicine to astrophysics and beyond, and the instruments needed to do the science have been slowly accreting over the years. There’s so much stuff up there that almost everywhere you turn there’s a box or pallet stuck down with hook-and-loop fasteners or bolted to some bulkhead, each one of them doing something interesting.

The science on the ISS isn’t contained completely within the hull, of course. The outside of the station fairly bristles with science, with packages nestled in among the solar panels and other infrastructure needed to run the spacecraft. Peering off into space and swiveling around to track targets is an instrument with the friendly name NICER, for “Neutron Star Interior Composition Explorer.” What it does and how it does it is interesting stuff, and what it’s learning about the mysteries of neutron stars could end up having practical uses as humanity pushes out into the solar system and beyond.

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