Spectrogram Drawing For Fun And Coding

It probably can’t have taken long after the first spectrum waterfall display was created, before somebody had a go at creating a waveform that would create an image in the waterfall. We don’t know who that pioneer was, but it’s over 20 years since Aphex Twin famously used the technique in their music, so it’s nothing new. If you fancy a go for yourself, [Gokberk Yaltirakli] has the project for you, creating waterfall images with an SDR from image files, using a bit of Python code.

The value here isn’t necessarily in creating the waterfall of Bitcoin logos that can be seen in the video he’s put on the page, instead it’s in the simple explanation of creating I and Q values for an SDR. The code is a bit slow so writes its values to a file which is output by a HackRF, but it could just as easily be used by any other capable output device such as GNU Radio and a soundcard if you too want an Aphex Twin moment. The hardware for displaying a spectrum waterfall doesn’t even have to be very complex.

Thanks [Leo] for the tip.

This Week In Security: Mysterious Mac Malware, An Elegant VMware RCE, And A JSON Mess

There’s a new malware strain targeting MacOS, Silver Sparrow, and it’s unusual for a couple reasons. First, it’s one of the few pieces of malware that targets the new M1 ARM64 processors. Just a reminder, that is Apple’s new in-house silicon design. It’s unusual for a second reason — it’s not doing anything. More precisely, while researchers have been watching, the command and control infrastructure didn’t provide a payload. Silver Sparrow has been positively found on nearly 30,000 machines.

The malware also has an intentional kill switch, where the presence of a particular file triggers a complete removal of the malware package. Researchers at Red Canary point out that this package behaves very much like a legitimate program, difficult to pick out as malware. Ars Technica got an off-the-record statement from Apple, indicating that they are tracking the situation, and have revoked the developer’s certificate used to sign the malware. It’s not entirely clear whether this prevents the malware running on already compromised machines, or just stops new infections.

So who’s behind Silver Sparrow? The observed stealth mode and other complexities suggest that this is more than a simple adware or ransomware campaign. Since it was discovered before the payload was delivered, we may never know what the purpose is. It may have been a government created campaign, targeting something specific. Continue reading “This Week In Security: Mysterious Mac Malware, An Elegant VMware RCE, And A JSON Mess”

Hackaday Podcast 107: FTDI Plays Music, LED Dimming Ain’t Easy, Measuring Poop Calories, And Sketchy Laser Cutters

Hackaday editors Mike Szczys and Elliot Williams gab about all of the geeky things. We had a delightful time watching NASA bring Perseverance down to the Red planet. In Kristina’s words, we pour one out for Fry’s Electronics. And then we jump into a parade of excellent hacks with a magnetic bearing for crooked ball screws, a science-based poop-burning experiment, and the music hack only microcontroller enthusiasts could love as an FTDI cable is plugged directly into a speaker. Smart circuit design is used to hack a dimmer into non-dimmable LED fixtures, and an octet of living clams are the early warning sensors for water pollution.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~60 MB)

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 107: FTDI Plays Music, LED Dimming Ain’t Easy, Measuring Poop Calories, And Sketchy Laser Cutters”

Bad Week For Boeing: Reports Of Third Engine Failure Causes Emergency Landing In Moscow

Early Friday morning a Boeing 777 performed an emergency landing in Moscow, according to Russian media. The Interfax news agency cites an anonymous source who claims the landing was caused by an engine failure on a flight from Hong Kong to Madrid. According to the Hong Kong civil aviation department this was a cargo flight. So far no injuries have been reported.

Two damaged fan blades from UA328, a Boeing 777 that returned safely to DIA shortly after takeoff

Engine failures happen, pilots train for them, and our airport infrastructure is setup to accommodate emergency landings like this. However, the timing of this reported failure is notable. This is the second engine failure on a 777 within a week, and the third to occur in a Boeing aircraft.

Shortly after takeoff on Saturday, February 20th, a United Airlines flight bound for Hawaii made an emergency landing after suffering a catastrophic failure of the right engine. The event was widely shared on social media, you likely saw the video from a passenger inside the Boeing 777-200 that shows the damaged engine on fire — if you haven’t you really should. There was also damage on the ground due to falling debris. This prompted Boeing to launch inspections of all 777-200s, and soon afterwards the NTSB published photos of the damaged engine. No injuries have been reported.

Two days later, on February 22nd, a Boeing 747-400 cargo plane operated by Longtail Aviation suffered an engine failure over the Netherlands, dropping parts that reportedly injured two people on the ground. This is a different model of aircraft but uses a Pratt & Whitney PW4000, in the same family as the Pratt & Whitney PW4070/4090 on the United 777-200.

Reports of this morning’s emergency landing in Moscow will need to be verified and investigated, and we have not seen confirmation on what type of engine the Rossiya Airlines B777-300ER used. For comparison the 777-300ERs of the United fleet and the 777-300ERs operated by Emirates both use General Electric engines rather than Pratt & Whitney models, so it is likely the Rossiya aircraft also had a GE engine.

The fact that the flights were all able to make safe landings is a testament to the redundant engineering of these aircraft. CNET did a deep dive into last Saturday’s engine failure and notes that it was an Extended-range Operations Performance Standards (ETOPS) aircraft capable of flying long distances on a single engine — necessary if an aircraft needed to make it half-way to Hawaii on one engine for an emergency landing. They also report on two other Pratt & Whitney PW-4000 engine failures in 2018 and 2000 2020, although as mentioned before, today’s incident likely didn’t involve an engine from this maker.

[Main image source: B777-300 by Maarten Visser CC-BY-SA 2.0]

Modified 3D Printer Makes A Great Microscope, Too

A false-color polarimetric image of sugar crystals floating in water.

Look past the melty plastic bits, and your average 3D printer is just a handy 3-axis Cartesian motion platform. This makes them useful for all kinds of things, and as [E/S Pronk] shows us, they can easily be modified into an automated polarimetric microscope!

The microscope build actually took two forms. One, a regular digital microscope any of us may be familiar with, using a C-mount microscope lens fitted to a Raspberry Pi HQ camera. The other, a polarimetric microscope, using an Allied Vision Mako G-508B POL polarimetric camera instead, with the same microscope lens. The polarimetric camera takes stunning false-color images, where the color values correspond to the polarization of the light bouncing off an object. It’s incredibly specialized hardware with a matching price tag, but [E/S Pronk] hopes to build a cheaper DIY version down the line, too.

3D printers make excellent microscopes, as they’re designed to make small precise movements and are easily controlled via G-Code. We’ve seen them used for other delicate purposes too – such as this one modified to become a soldering robot. Video after the break.

Continue reading “Modified 3D Printer Makes A Great Microscope, Too”

Should I Use Wheels Or Tracks?

When it comes to dominating offroad performance, many people’s first thought is of tracked vehicles. Bulldozers, tanks and excavators all use treads, and manage to get around in difficult terrain without breaking a sweat. Today, we’re exploring just what makes tracked vehicles so capable, as well as their weaknesses.

It’s All About Ground Pressure

The various parts of a tank’s propulsion system.

Let’s first look at how tank tracks work. There are a huge variety of designs, with differences depending on application. Different trends have been followed over time, and designs for military use in combat differ from those used for low-speed construction machines, for example. But by looking at a basic tank track design, we can understand the basic theory. On tanks, the track or tread itself is usually made up of individual steel links that are connected together with hinges, though other machines may use rubber tracks instead. The tracks are wrapped around one or more drive wheels, often cogged, which directly pull on the track. On the bottom of the vehicle are the road wheels, which ride on top of the track where it lies on the ground.  The weight of the vehicle is carried through the road wheels and passed on to the tread, spreading out the load across a broader area. Outside of this, the track system may also have one or more idler wheels used to keep the track taught, as well as return rollers to guide the track back around without touching the road wheels.

Continue reading “Should I Use Wheels Or Tracks?”

DIY All-Transistor Addressable Pixel

By now most readers should be used to addressable LEDs, devices that when strung out in a connected chain can be individually lit or extinguished by a serial data stream. Should you peer at one under a microscope you’ll see alongside the LED dies an integrated circuit that handles all the address decoding. It’s likely to be quite a complex device, but how simply can its functions be replicated? It’s a theme [Tim] has explored in the TransistorPixel, and addressable LED board that achieves addressability with only 17 transistors.

It uses a surprisingly straightforward protocol, in which a pulse longer than 500ns enables the LED while a shorter one turns it off. Subsequent pulses in a train are passed on down the line to the next device. A 20µs absence of a pulse resets the string and sets it to wait for the next pulse train. Unlike the commercial addressable LEDS there is only a single colour and no suport for gradated brightness, but it’s still an impressive circuit.

Under the hood is some very old-school RTL logic, a monostable to detect the pulse and a selection of gates and a latch to capture the state and forward to the chain. It’s laid out on a PCB in order of circuit function, and while we can see that maybe it’s not a practical addresssable LED for 2021, it’s likely that it could be made into a much smaller PCB if desired.

Perhaps unsurprisingly given the ready availability of addressable LEDs, we’ve not seen many home made ones. This addressable 7-segment display may be the closest.