Hackaday Links: April 7, 2024

April 7, 2024 by Tom Nardi 12 Comments

Folks with a bit of knowledge about network security commonly use virtual private networks (VPNs) when out and about. Whether you’re connecting to public WiFi or somebody passes you a questionable Ethernet cable at a hacker con, it’s nice to have a secure endpoint to tunnel all of your traffic. As a secondary bonus, connecting through a VPN can obscure your physical location. It’s that second feature that has a bunch of people jumping on the VPN bandwagon as they try to dodge the recent porn age checks that have gone into effect in a number of states. According to a recent article in PopSci, one particular VPN provider saw a 275% jump in demand on the same day that PornHub cut off access to users in Texas. While the debate over underage users accessing adult content is far outside of our wheelhouse, anything that gets more users connecting to the Internet via encrypted means is arguably a net positive.

If you wanted somebody from the Geek Squad to set up that VPN so you can get back ~~on PornHub~~ to work securely from the local coffee shop, you might be out of luck. Reports have been coming in that Best Buy’s mobile nerd division is seeing sweeping layoffs. Geeks were told to stay home on Tuesday and await a call from corporate, at which point many got the surprising news that they no longer had a job. The /r/GeekSquad subreddit has been a rallying point for staff who got the axe, with the user [jaym026] posting what we assume is an AI-generated inspirational speech from Optimus Prime. Of course, it sucks for anyone to lose their job, especially with the way things are these days. Still, we’re willing to bet almost none of those affected will look back on the day they were let go from an increasingly irrelevant brick-and-mortar electronics store as a low point in their professional careers.

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A DIY DIN rail mounted rack of PLC components for home automation

2024 Home Sweet Home Automation: A DIY SCADA Smart Home

March 20, 2024 by Dave Rowntree 22 Comments

A SCADA-style display of icons and control buttons — Touch-screen control and monitoring

Supervisory control and data acquisition, or SCADA, systems sit in the background in industrial settings, performing all kinds of important jobs but in an ad-hoc setup, depending on the precise requirements of the installation. When we think about home automation systems, they’re pretty much the same deal: ad-hoc systems put together from off-the-shelf components and a few custom bits thrown in. [Stefan Schnitzer] clearly has significant knowledge of SCADA in an industrial setting and has carried this over into their home for their entry into the Hackaday 2024 Home Sweet Home Automation Contest. Continue reading “2024 Home Sweet Home Automation: A DIY SCADA Smart Home” →

Running Power And Data Over Just Two Wires

March 19, 2024 by Lewin Day 50 Comments

When you’re hooking up equipment across a vehicle, you’re often stuck sending power and data to and from things like sensors or actuators. The more wires you have to run, the more hassle, so it’s desirable to get this number as low as possible. That’s an especially big deal in the world of cycling electronics, where every additional gram is considered a drawback. To this end, companies have developed two-wire methods of sending power and data together, and now, [Keith Wakeham] has devised his own way of doing so.

[Keith] was inspired by Shimano’s E-Tube system which is fairly fancy in its encoding schemes, but he went his own way. His concept relied on old-school On-Off Keying methods to take a signal and capacitively couple a signal into power lines. He explains the theory behind the method, and shares schematics that can be used to actually communicate over power lines. Then, he shows off the real hardware that he built to test the concept for himself.

The results? Good! [Keith] was able to maintain speeds of 57,600 bits/second even with an electrically-noisy gear motor operating on the lines. That’s more then enough for all kinds of applications.

If you’ve got your own data-over-powerline hacks, don’t hesitate to let us know. Continue reading “Running Power And Data Over Just Two Wires” →

Photoresistors Provide Air Gap Data Transfer, Slowly

March 19, 2024 by Bryan Cockfield 50 Comments

One of the simplest ways of keeping a computer system secure is by using an air gap — that is, never actually connecting the system to the network. This can often include other peripherals like USB drives and other removable storage as well, so getting information to and from secure (or compromised) systems behind air gaps can often present a challenge. But assuming you have local access to the computer and your parts bin handy, these optical solutions from [Nikolay] can allow data transfer to or from such off-line computers.

[Nikolay]’s specific use case for this project is to transfer small amounts of information to or from computers that may be compromised in some way, or computers that might otherwise be dangerous to connect to other equipment. There’s actually several methods described in the project, the first involves temporarily attaching a photoresistor to the computer’s screen which has been wired into the remains of a USB keyboard. A script running on the compromised machine translates data into a series of white and black squares. The sensors can detect these patterns much like playing Duck Hunt on an old CRT television and transmit the data across the air gap with reasonable certainty nothing harmful crossed with it.

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Hackaday Links: March 17, 2024

March 17, 2024 by Dan Maloney 16 Comments

A friend of ours once described computers as “high-speed idiots.” It was true in the 80s, and it appears that even with the recent explosion in AI, all computers have managed to do is become faster. Proof of that can be found in a story about using ASCII art to trick a chatbot into giving away the store. As anyone who has played with ChatGPT or its moral equivalent for more than five minutes has learned, there are certain boundary conditions that the LLM’s ~~creators~~ lawyers have put in place to prevent discussion surrounding sensitive topics. Ask a chatbot to deliver specific instructions on building a nuclear bomb, for instance, and you’ll be rebuffed. Same with asking for help counterfeiting currency, and wisely so. But, by minimally obfuscating your question by rendering the word “COUNTERFEIT” in ASCII art and asking the chatbot to first decode the word, you can slip the verboten word into a how-to question and get pretty explicit instructions. Yes, you have to give painfully detailed instructions on parsing the ASCII art characters, but that’s a small price to pay for forbidden knowledge that you could easily find out yourself by other means.

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A bias tee module added inside the Starlink terminal, connected to the pads where a GPS antenna used to be wired

GPS Antenna Mods Make Starlink Terminal Immune To Jammers

March 6, 2024 by Arya Voronova 69 Comments

The Starlink receivers need positioning and precise timing information to function, and currently the best way to get that information is to use a global navigation satellite system (GNSS) such as GPS. Unfortunately, the antenna used for this secondary satellite connection leaves something to be desired. Of course, when it comes to solving Starlink problems, there’s no one best than [Oleg Kutkov], whose duty is to fix and improve upon Starlink terminals used in Ukraine — and when the specific problem is GPS bands getting jammed by the invading military, you better believe that a fix is due.

[Oleg] sets the scene, walking us through the evolution of GPS circuitry on the Starlink terminals. Then he shows us the simplest mods you can do, like soldering an improved passive antenna in place of the chip antenna currently being used. Then, he takes it up a notch, and shows us how you could attach an active antenna by using a bias tee module, a mod that would surely work wonders on more than just this device! Then, he brings out the test result tables — and the differences are impressive, in that the Starlink terminals with active antenna mods were able to get GPS signal in areas with active jamming going on, while the unmodified ones could not.

The post is exceptionally accessible, and a must read for anyone wondering about GPS antenna reception problems in customer-accessible devices. This is not the only Starlink hardware mod we’ve seen [Oleg] make, we’ve just covered his Starlink Ethernet port restoration journey that meticulously fixes Ethernet connectivity oversights in the newer models, and the blog also has an article about powering Starlink terminals without the need for PoE, so, do check it out if you’re looking for more!

Reverse Engineering The Behringer Ultranet Protocol

March 5, 2024 by Richard Baguley 22 Comments

Ultranet is a protocol created by audio manufacturer Behringer to transmit up to 16 channels of 24-bit sound over a Cat-5 cable. It’s not an open standard, though: Behringer doesn’t offer an API or protocol description to build your own Ultranet devices. But that didn’t stop [Christian Nödig], thanks to a defective mixer, he poked into the signals and built his own Ultranet receiver.

Ultranet runs over Cat-5 ethernet cables but isn’t an ethernet-based protocol. The electrical protocols of Ultranet are identical to Ethernet, but the signaling is different, making it a Level 1 protocol. So, you can use any Cat-5 cable for Ultranet, but you can’t just plug an Ultranet device into an Ethernet one. Or rather, you can (and neither device should explode), but you won’t get anything out of it.

Instead, [Christian]’s exploration revealed that Ultranet is based on another standard: AES/EBU, the bigger professional brother of the SPD/IF socket on HiFi systems. This was designed to carry digital audio over an XLR cable, and Behringer has taken AES/EBU and tweaked it to run over a single twisted pair. With two twisted pairs in the cable carrying a 192 kbps signal, you get sixteen channels of 24-bit audio in total over two twisted pairs inside the Cat-5 cable.

That’s a bit fast for a microcontroller to decode reliably, so [Christian] uses the FPGA in an Arduino Vidor 4000 MKR in his receiver with an open-source AES decoder core to receive and decode the Ultranet signal into individual channels, which are passed to an ADC and analog output.

In effect, [Christian] has built a 16-channel mixer, although the mixing aspect is too primitive for actual use. It would be great for monitoring, though, and it’s a beautiful description of how to dig into protocols like Ultranet that look locked up but are based on other, more open standards.

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