Raspberry Pi Pico ADC Characterized

March 15, 2021 by Al Williams 21 Comments

[Markomo] didn’t find much useful information about the Raspberry Pi PIco’s analog to digital converter, so he decided to do some tests to characterize it. Lucky for us, he documented the findings and shared them. The results are in a series of blog posts that cover power supply noise, input-referred noise, signal to noise ratio, and distortions.

There are some surprising results. For example, the Pico’s low noise regulator mode appears to produce more noise than having it set for normal operation. There also appears to be a large spike in nonlinearity around certain measurements.

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Cricut Decides To Charge Rent For People To Fully Use The Cutting Machines They Already Own

March 15, 2021 by Jenny List 272 Comments

UPDATE: Hackaday was contacted by a PR company claiming to represent Cricut. They clarified that machines are not deactivated upon resale, but the new owner will need to set up their own online account.

UPDATE #2 (3/21/21): In the wake of this controversy, Cricut have announced that they will not move forward with the upload limit for customers who are not paying subscribers.

In our community we like to think of ourselves as pioneers in the field of domestic CNC machinery, with our cheap 3D printers. But there’s another set of people who were way ahead of us, and they’re a rather unexpected one, too. Crafters were using CNC cutting machines well before we were, and while some may deride them when used for sparkly greeting cards sold on Etsy, they can be an extremely useful tool for much more than that. Probably the best known brand of cutter comes from Cricut, and that company has dropped a bombshell in the form of an update to the web-based design software that leaves their now very annoyed users with a monthly upload limit of 20 new designs unless they sign up for a Cricut Access Plan that costs $9.99 on monthly payments. Worse still, a screenshot is circulating online purporting to be from a communication with a Cricut employee attempting to clarify matters, in which it is suggested that machines sold as second-hand will be bricked by the company.

Also, soon we will be making changes that affect members who use the free Design Space app without a Cricut Access plan. Every calendar month, these members will be allowed to upload up to 20 personal images and/or patterns. Members with a paid Cricut Access plan will have unlimited uploads.

We’d like to think that given the reaction from their online community the subscription plan will backfire, but unlike the world of 3D printing their market is not necessarily an online-savvy one. A crafter who buys a Cricut from a bricks-and-mortar warehouse store and uses it with Cricut cartridges may not balk at being required to pay rent to use hardware that’s already paid for in the same way a member of our community with a 3D printer would. After all, Cricut have always tried to make their software a walled garden. ~~However if the stories about second-hand models being bricked turn out to bear fruit that might be a different matter.~~

There are of course plenty of alternative CNC cutting machines (The favourite in ones that have made it here seems to be the Silhouette Cameo) that don’t come with this type of baggage, and the online Cricut community are busily raising their profile in the wake of this news. Probably because of their restricted functionality there have been very few hacks here using a Cricut machine, but all of this leaves us wondering whether the machines themselves could be exploited to take less restrictive firmware.

Header image: Factorof2 (CC BY-SA 2.0)

Rare Diode Threatens Coast Guard’s Arctic Ambitions

March 14, 2021 by Tom Nardi 164 Comments

The United States Coast Guard heavy icebreaker Polar Star is literally a one-of-a-kind ship. After its sister Polar Sea was deactivated in 2010 it became the most powerful icebreaker in the fleet, and one of only two US icebreakers capable of operating in the treacherous polar regions. The vessel is critical to protecting America’s scientific and economic interests in the Arctic, but according to a recent article in Business Insider, the ship’s age and scarcity of spare parts is making an already difficult mission even harder.

In the article, Captain William Woityra specifically mentions that the ship’s diesel-electric propulsion system is running on borrowed time as the diodes used in its AC/DC rectifier are no longer manufactured. With none remaining in the Coast Guard’s inventory, the crew has had to turn to eBay to source as many spares as possible. But once their hoard runs out, Captain Woityra fears his ship will be dead in the water:

We’ve got a few dozen of these in a box on a shelf, when they’re gone, the ship will not be able to run anymore. It’s really kind of disconcerting … that this ship, and this operation, and the US’s icebreaking presence in the Arctic is reliant on a box of spare parts that … there are no more of.”

The 45 year old ship received a $60 million refit in 2013, but that was only expected to extend the hard-working vessel’s life by 8 to 10 years. There was a proposal for a far more thorough overhaul, one which potentially would have keep the Polar Star in service until nearly 2040; but with an estimated cost of $400 million, Congress decided to go with the more economical stop-gap refit.

This story comes just days after the Air Force announced it’s looking for a few good hackers to help reverse engineer components on its aging fleet of B-2 bombers. Much like the Polar Star’s vintage rectifier diodes, spare parts for the the stealthy aircraft are getting increasingly difficult to find.

While the Air Force has enough money in the budget to get replacements made, the Coast Guard will just have to hope their stock of diodes holds out a little while longer. Congress has already approved the Polar Security Cutter Program, a fleet of next-generation icebreakers designed to be comparable to newer Russian and Chinese vessels. The first of these ships could set sail by 2024, providing the Polar Star some much-needed backup.

[Thanks to Chuckz for the tip.]

A Different Kind Of 3D Printer: Desktop Holograms

March 12, 2021 by Al Williams 38 Comments

Holograms aren’t new, but a desktop machine that spits them out could be available soon, presuming LitiHolo’s Kickstarter pans out. The machine will have a $1600 retail price and fits in a two-foot square. It can generate 4×5 inch holograms with 1mm hogels (the holo equivalent of a pixel).

The machine allows for 23 view zones per hogel and can create moving holograms with a few seconds of motion — like the famous kiss-blowing holograms.

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A Scientist Made An Artificial Black Hole In The Lab, And You Won’t Believe What Happened Next

March 8, 2021 by Dan Maloney 53 Comments

OK, that was a little click-baity, but then again, so was the announcement this week that a scientist had confirmed Hawking radiation with a lab-grown black hole. It sure got our attention, at least.

As it turns out, the truth is both less and more than meets the eye. The article above was eventually edited to better reflect the truth that, alas, we have not yet found a way to create objects so massive that even light cannot escape them. Instead, physicist [Jeff Steinhauer] and colleagues at the Technion-Israel Institute of Technology have developed an acoustic model of black holes, which is what was used to observe the equivalent of Hawking radiation for the first time. Hawking radiation is the theoretical exception to the rule that nothing makes it out of a black hole and would imply that black holes evaporate over time. The predicted radiation would be orders of magnitude weaker than the background radiation, though, making it all but impossible to detect.

That’s where [Steinhauer]’s sonic black holes come in. In these experiments, phonons, packets of mechanical vibrations that stand in for photons, are trapped in a fast-moving stream of fluid. The point in the stream where its speed straddles the local speed of sound is the equivalent to a real black hole’s event horizon; phonons inside that boundary can never escape. Except, of course, for the sonic equivalent of Hawking radiation, which the researchers found after 97,000 attempts.

When we first stumbled upon this story, we assumed a lab-grown black hole, even an acoustic analog, would take a CERN’s-worth of equipment to create. It turns out to be far simpler than that; [Steinhauer], in fact, built his black hole machine singlehandedly from relatively simple equipment. The experiments do require temperatures near absolute zero and a couple of powerful lasers, so it’s not exactly easy stuff; still, we can’t help but wonder if sonic black holes are within the reach of the DIY community. Paging [Ben Krasnow] and [Sam Zeloof], among others.

[Featured image credit: Nitzan Zohar, Office of the Spokesperson, Technion]

The B-2 Bomber: Those Who Forget History Are Doomed To Reverse Engineer It

March 7, 2021 by Al Williams 82 Comments

The Drive had an interesting post recently, about someone noticed a procurement from the U. S. Air Force to reverse engineer the B-2 bomber’s Load Heat Exchanger (whatever that is). You’d think if the Air Force wanted to reverse engineer something, they’d be looking at another country’s aircraft. What can this mean?

Presumably, the original plans for the system have been lost, or maybe the company who made them is long gone and the tooling to create new ones along with it. Then again, maybe the assembly needs parts that you can no longer get. The Drive has another interesting speculation: perhaps the plans were so secret that were accidentally destroyed.

You don’t hear much about the B-2. There are only 20 left of the 21 built, at least that we know about. Original plans in the 1980s called for 132, but the end of the Cold War spelled the end for the stealth bomber. They get an overhaul every nine years. The Drive also speculates that this may be part of the Air Force’s desire to digitize spare parts and use 3D printing, but — honestly — it doesn’t sound that way to us. Especially since the fleet will retire no later than 2032, so whatever is replaced is only needed for a decade.

If you think you want to have a go, here’s the help wanted ad from the Air Force. If you read the text, it’s pretty clear they have some defective units that need replacement and it sounds like no one knows how to do it with existing materials. Not many of us get to design things that are still working nearly three decades later. Keeping a supply of parts and even know-how for something built in the 1990s isn’t trivial. Something to think about if you design something with a long service life.

The B-2 is a stealth bomber and while one did crash, it wasn’t shot down. The F-117A — the stealth fighter — was shot down against all odds, though. While the B-2 appears to be quite a plane, we prefer our bombers a little bit older. Still, you might enjoy the video below about the B-2’s chief engineer, although he doesn’t mention the Load Heat Exchanger.

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NASA’s Perseverance Rover Makes Its First Martian Tracks

March 6, 2021 by Zach Zeman 11 Comments

There’s a special kind of anxiety that comes from trying out a robotic project for the first time. No matter the size, complexity, or how much design and planning has gone into it, the first time a creation moves under its own power can put butterflies in anyone’s stomach. So we can imagine that many people at NASA are breathing a sigh of relief now that the Perseverance rover has completed its first successful test drive on Mars.

To be fair, Perseverance was tested here on Earth before launch. However, this is the first drive since the roving scientific platform was packed into a capsule, set on top of a rocket, and flung hundreds of millions of miles (or kilometers, take your pick) to the surface of another planet. As such, and true to NASA form, the operators are taking things slow.

This joyride certainly won’t be setting speed records. The atomic-powered vehicle traveled a total of just 21.3 feet (6.5 meters) in 33 minutes, including forward, reverse, and a 150 degree turn in-between. That’s enough for the mobility team to check out the drive systems and deem the vehicle worthy of excursions that could range 656 feet (200 meters) or more. Perseverance is packed with new technology, including an autonomous navigation system for avoiding hazards without waiting for round-trip communication with Earth, and everything must be tested before being put into full use.

A couple weeks have passed since the world was captivated by actual video of the rover’s entry, descent, and landing, and milestones like this mark the end of that flashy, rocket-powered skycrane period and the beginning of a more settled-in period, where the team works day-to-day in pursuit of the mission’s science goals. The robotic arm and several on-board sensors and experiments have already completed their initial checks. In the coming months, we can look forward to tons of data coming back from the red planet, along with breathtaking pictures of its alien surface and what will hopefully be the first aircraft flown on another world.