Rare Diode Threatens Coast Guard’s Arctic Ambitions

March 14, 2021 by 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.

Polar Security Cutter

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.]

An Infrared-Activated Solder Fume Extraction Fan

March 14, 2021 by 13 Comments

Even the most safety-conscious hackers among us might overlook protective gear when we’re just doing a quick bit of soldering. Honestly, though, eye protection is always a necessity. And those wisps of smoke, which drift so elegantly off the hot part of the iron, really shouldn’t drift directly into our nostrils. This is especially true if soldering you make a daily habit, or if you use lead-based solder.

And so, in defense of his lungs, [Jeremy S Cook] added a battery-powered fume extraction fan to his custom, concrete-based solder squid. Without proper power controls, though, the fan could easily drain its battery while no actual solder activity was occurring. To tackle that problem, he recently upgraded his system with a passive infrared (PIR) sensor to control when the fan turns on and off. The PIR sensor detects motion, enabling the fan only when it sees busy hands in its view, so he no longer needs to muck around with manual controls.

Despite a large increase in functionality, the design is relatively straightforward and uses off-the-shelf components, making it an accessible project for anyone who knows their way around an iron. [Jeremy] also upgraded his power source to a LiPo battery with onboard charger, which keeps the build light, maneuverable, and easy to get close to whatever he’s working on.

Whether you build or buy, a fume extractor will help fight off the famously face-seeking solder smoke on your workbench. Which is a good thing, too, because that smoke carries more than just the alluring aromas of making.

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Your Plants Can Take Care Of Themselves Now

March 14, 2021 by 41 Comments

One of [Sasa]’s life goals is to be able to sit back in his home and watch as robots perform all of his work for him. In order to work towards this goal, he has decided to start with some home automation which will take care of all of his house plants for him. This project is built from the ground up, too, and is the first part of a series of videos which will outline the construction of a complete, open-source plant care machine.

The first video starts with the sensors for the plants. [Sasa] decided to go with a completely custom module based on the STM32 microcontroller since commercial offerings had poor communications designs and other flaws. The small board is designed to be placed in the soil, and has sensors for soil moisture as well as other sensors for amount of light available and the ambient temperature. The improvements over the commercial modules include communication over I2C, allowing a large number of modules to communicate over a minimum of wires and be arranged in any way needed.

For this build everything is open-source and available on [Sasa]’s GitHub page, including PCB layouts and code for the microcontrollers. We’re looking forward to the rest of the videos where he plans to lay out the central unit for handling all of these sensors, and a custom dashboard for controlling them as well. Perhaps there will also be an option for adding a way to physically listen to the plants communicate their needs as well.

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An Anti-Tamper Mesh Plugin For KiCad

March 14, 2021 by 31 Comments

Physical access to electronics generally means all bets are off when it comes to information security. But in special cases this is just unacceptable and a better solution must be found. Consider the encryption keys used by point of sale machines. To protect them, the devices incorporate anti-tamper mechanisms that will wipe the keys from memory if the device is opened. One such technique is to use a mesh of traces on a circuit board that are monitored for any changes in resistance or capacitance. [Sebastian Götte] has been researching in this area and wrote a KiCad plugin to automatically generate tamper-detection mesh.

The idea is pretty simple, place traces very close to one another and it makes it impossible to drill into the case of a device without upsetting the apple cart. There are other uses as well, such as embedding them in adhesives that destroy the traces when pried apart. For [Sebastian’s] experiments he’s sticking with PCBs because of the ease of manufacture. His plugin lays down a footprint that has four pads to begin and end two loops in the mesh. The plugin looks for an outline to fence in the area, then uses a space filling curve to generate the path. This proof of concept works, but it sounds like there are some quirks that can crash KiCad. Consider taking a look at the code if you have the expertise to help make it more stable.

We’ve seen these anti-tamper meshes in practice in the VeriFone payment terminal that [Tom Nardi] tore down a couple of years ago. The approach that [Sabastian] took with the plugin actually produces a more complex mesh than was in use there as it only really used vertical lines for the traces.

Web Pages (and More) Via Shortwave

March 13, 2021 by 30 Comments

If you are a ham radio operator, the idea of sending pictures and data over voice channels is nothing new. Hams have lots of techniques for doing that and — not so long ago — even most data transmissions were over phone lines. However, now everyone can get in on the game thanks to the cheap availability of software-defined radio. Several commercial shortwave broadcasters are sending encoded data including images and even entire web pages. You can find out more at the Swradiogram website. You can also find step-by-step instructions.

WINB in Pennsylvania and WRMI Florida both have shows that include interspersed data. To play along, you’ll need a decoder like Fldigi or TIVAR. If you don’t have sufficient radio gear, you can probably borrow some from the Internet.

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It’s Not A Computer If It Doesn’t Have A Cartridge Slot

March 13, 2021 by 25 Comments

For viewers of sci-fi TV and films from the 1960s onwards, the miniaturisation of computer hardware has been something of a disappointment. Yes, it’s amazing that we can get 1.21 Jigabytes onto a memory card that fits comfortably under a postage stamp, but we were promised a different future. One of satisfyingly chunky data modules that activated everything from starships to handheld data recorders to malevolent rogue supercomputers, and one that has so far only materialised in the form of cartridges for game consoles.

Our colleague [Tom Nardi] has the solution for his cyberdeck though, in the form of 3D-printed cartridge shells that hide regular USB hardware and mate with a concealed USB socket in the slot. So far he’s designed cartridges for Flash drives, WiFi and Bluetooth adapters, a Wemos D1 Mini, a receptacle, and a parametric reference design.

It’s a bit of pleasing retro fun, but behind it all could be a surprisingly practical and useful expansion system. Each cartridge contains enough space for a lot of extra electronics, so it’s almost the ideal format for building a USB-driven project inside. Best of all since the interface is USB, it still works with conventional USB plugs and sockets. We like the idea, and it’s one that would be a good addition to any cyberdeck project.

We’re far more used to seeing home-made cartridges on game consoles.

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Networked Nightlights Glow Together

March 13, 2021 by 4 Comments

Nightlights are a great way to calm children who may be afraid of the dark, as well as to avoid stubbing your toe on furniture in the hallway. However, in this day and age of connected everything, they can do so much more. [Andy] came up with a great way to do just that, creating an advanced networked solution to suit his needs.

[Andy’s] nightlight serves not just in the usual fashion, but also as an indicator for his children. Depending on the time of day, the colour changes, indicating whether it’s time for bed, or also, if it’s too early to get out of bed in the morning and start watching cartoons. Each nightlight around the house runs on an ESP8266, which lights up using a set of WS2812B LEDs. The ESP8266 decides on colour values based on commands from a basic webserver running on a Raspberry Pi, updated every minute. This gives [Andy] the flexibility to make changes in one place, that then automatically roll out across the Nightlight Network (TM).

It’s a fun way of teaching the kids not to ruin a good Saturday sleep in, as well as serving as a fun colourful nightlight, too. Of course, luxury smart nightlights are becoming a thing, as this teardown of a Bluetooth unit shows. If you’ve built your own, be sure to drop us a line!