Author: Dan Maloney

3367 Articles

Reverse Engineering “The Seven Words (and More) You Can’t Say On TV”

November 21, 2022 by 24 Comments

For as visionary as he was, [George Carlin] vastly underestimated the situation with his classic “Seven Words You Can’t Say on TV” bit. At least judging by [Ben Eater]’s reverse engineering of the “TVGuardian Foul Language Filter” device, it seems like the actual number is at least 20 times that.

To begin at the beginning, a couple of weeks ago [Alec] over at everyone’s favorite nerd hangout Technology Connections did a video on the TVGuardian, a device that attempted to clean up the language of live TV and recorded programming. Go watch that video for the details, but for a brief summary, TVGuardian worked by scanning the closed caption text for naughty words and phrases, muted the audio when something suggestive was found in a lookup table, and inserted a closed caption substitute for the offensive content. In his video, [Alec] pined for a way to look at the list of verboten words, and [Ben] accepted the challenge.

The naughty word list ended up living on a 93LC86 serial EEPROM, which [Ben] removed from his TVGuardian for further exploration. Rather than just plug it into a programmer and dumping the contents, he decided to roll his own decoder with an Arduino, because that’s more fun. And can we just point out our ongoing amazement that [Ben] is able to make watching someone else code interesting?

The resulting NSFW word list is titillating, of course, and the video would be plenty satisfying if that’s where it ended. But [Ben] went further and figured out how the list is organized, how the dirty-to-clean substitutions are made, and even how certain words are whitelisted. That last bit resulted in the revelation that Hollywood legend [Dick Van Dyke] gets a special whitelisting, lest his name becomes sanitized to a hilarious [Jerk Van Gay].

Hats off to [Alec] for inspiring [Ben]’s fascinating reverse engineering effort here.

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Hackaday Links: November 20, 2022

November 20, 2022 by 16 Comments

Lots of space news this week, with the big story being that Artemis I finally blasted off for its trip to the Moon. It was a spectacular night launch, with the SLS sending the crew-rated but vacant — well, mostly vacant — Orion spacecraft on a week-ish long trip to the Moon, before spending a couple of weeks testing out a distant retrograde orbit. The mission is already returning some stunning images, and the main mission goal is to check out the Orion spacecraft and everything needed for a crewed Artemis II lunar flyby sometime in 2024. If that goes well, Artemis III will head up in 2025 with a crew of four to put the first bootprints on the Moon in over 50 years.

Of course, like the Apollo missions before it, a big part of the crewed landings of the Artemis program will likely be the collection and return of more lunar rock and soil samples. But NASA likes to hedge its bets, which is perhaps why they’ve announced an agreement to purchase lunar regolith samples from the first private company to send a lander to the Moon. The Japanese start-up behind this effort is called ispace, and they’ve been issued a license by the Japanese government to transfer samples collected by its HAKUTO-R lander to NASA. Or rather, samples collected on the lander — the contract is for NASA to take possession of whatever regolith accumulates on the HAKUTO-R’s landing pads. And it’s not like ispace is going to return the samples — the lander isn’t designed to ever leave the lunar surface. The whole thing is symbolic of the future of space commerce, which is probably why NASA is only paying $5,000 for the dirt.

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This Standalone Camera Gets The Picture Through With SSTV

November 20, 2022 by 12 Comments

These days, sending a picture to someone else is as simple as pulling out your smartphone and sending it by email or text message. It’s so simple a child can do it, but that simple user experience masks a huge amount of complexity, from the compression algorithms in the phones to the huge amount of distributed infrastructure needed to connect them together. As wonderful and enabling as all that infrastructure can be, sometimes it’s just too much for the job.

That seems to have been the case for [Dzl TheEvilGenius], who just wanted to send a low-resolution image from a remote location. It turns out that hams solved that problem about 70 years ago with slow-scan television, or SSTV. While most of the world was settling down in front of “I Love Lucy” on the regular tube, amateur radio operators were figuring out how to use their equipment to send pictures around the world. But where hams of yore had to throw a considerable amount of gear at the problem, [Dzl] just used an ESP-32 with a camera and some custom code to process the image. The output from one of the MCU’s GPIO pins is a PWM audio signal which can be fed directly into the microphone input of a cheap portable transceiver.

To decode the signal, [Dzl] used one of the many SSTV programs available. There’s no mention of the receiver, although it could be pretty much anything from another Baofeng to an SDR dongle. The code is available in the article, as is an audio file of an encoded image, if you just want to play around with the receiving and decoding side of the equation.

We could see something like this working for a remote security camera, or even for scouting hunting spots. If you want to replicate this, remember that you’ll need a license if you want to transmit on the ham bands — relax, it’s easy.

Faceless Clock Makes You Think Twice About How It Works

November 18, 2022 by 23 Comments

We love projects that make you do a double-take when you first see them. It’s always fun to think you see one thing, but then slowly realize everything is not quite what you expected. And this faceless analog clock is very much one of those projects.

When we first saw [Shinsaku Hiura]’s “Hollow Clock 4,” we assumed the trick to making it look like the hands were floating in space would rely on the judicious use of clear acrylic. But no, this clock is truly faceless — you could easily stick a finger from front to back. The illusion is achieved by connecting the minute hand to the rim of the clock, and rotating the whole outer circumference through a compact 3D printed gear train. It’s a very clever mechanism, and it’s clear that it took a lot of work to optimize everything so that the whole look of the clock is sleek and modern.

But what about the hour hand? That’s just connected to the end of the minute hand at the center of the clock’s virtual face, so how does that work? As it is with most things that appear to be magical, the answer is magnets. The outer rim of the clock actually has another ring, this one containing a pair of neodymium magnets. They attract another magnet located in the very end of the hour hand, dragging it along as the hour ring rotates. The video below shows off the secrets, and it gives you some idea of how much work went into this clock.

We’re used to seeing unique and fun timepieces and other gadgets from [Shinsaku Hiura] — this up-flipping clock comes to mind, as does this custom RPN calculator — but this project is clearly a step beyond.

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Hackaday Podcast 193: Found Computers, Internet Over WhatsApp, Two-Factor C64, Shifting Cars, And Self-Shooting Fighter Planes

November 18, 2022 by 4 Comments

This week, Editor-in-Chief Elliot Williams and Staff Writer Dan Maloney review the literature on a hack-packed week of action. We’ll find a Linux machine inside just about anything, including curb-side TVs and surprisingly secure EV chargers. No Internet? No problem — just tunnel IP through WhatsApp! We’ll see that 3D printers can be repurposed for lab automation of the cheap, build the worst — but coolest — 2FA dongle of all time, and see how a teetering tower of cards can make your old motherboard think any ISA card is plugged into it. Worried that driving an EV is going to be a boring experience? Don’t be — maybe you’ll still get to jam through the gears. But if you do, rest assured there’ll be plenty of careful engineering done to see if it’s safe. Err, at least we hope so…

Download the podcast for safe keeping.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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Reverse Engineering Reveals EV Charger Has A Sense Of Security

November 16, 2022 by 11 Comments

As more and more electric vehicles penetrate the market, there’s going to have to be a proportional rise in the number of charging stations that are built into parking garages, apartment complexes, and even private homes. And the more that happens, the more chargers we’re going to start seeing where security is at best an afterthought in their design.

But as this EV charger teardown and reverse engineering shows, it doesn’t necessarily have to be that way. The charger is a Zaptec Pro station that can do up to 22 kW, and the analysis was done by [Harrison Sand] and [Andreas Claesson]. These are just the kinds of chargers that will likely be widely installed over the next decade, and there’s surprisingly little to them. [Harrison] and [Andreas] found a pair of PCBs, one for the power electronics and one for the control circuits. The latter supports a number of connectivity options, like 4G, WiFi, and Bluetooth, plus some RFID and powerline communications. There are two microcontrollers, a PIC and an ARM Cortex-A7.

Despite the ARM chip, the board seemed to lack an obvious JTAG port, and while some unpopulated pads did end up having a UART line, there was no shell access possible. An on-board micro SD card slot seemed an obvious target for attack, and some of the Linux images they tried yielded at least a partial boot-up, but without knowing the specific hardware configuration on the board, that’s just shooting in the dark. That’s when the NAND flash chip was popped off the board to dump the firmware, which allowed them to extract the devicetree and build a custom bootloader to finally own root.

The article has a lot of fascinating details on the exploit and what they discovered after getting in, like the fact that even if you had the factory-set Bluetooth PIN, you wouldn’t be able to get free charging. So overall, a pretty good security setup, even if they were able to get in by dumping the firmware. This all reminds us a little of the smart meter reverse engineering our friend [Hash] has been doing, in terms of both methodology and results.

Thanks to [Thinkerer] for the tip.

Getting To The Heart Of A Baofeng

November 15, 2022 by 32 Comments

In amateur radio circles, almost no single piece of equipment serves as more of a magnet for controversy than the humble Baofeng handheld transceiver. It’s understandable — the radio is a shining example of value engineering, with just enough parts to its job while staying just on the edge of FCC rules. And at about $25 a pop, the radios are cheap enough that experimentation is practically a requirement of ownership.

But stripped down as the Baofeng may be, it holds secrets inside that are even more tempting to play with than the radio itself. And who better than [HB9BLA], a guy who has a suspiciously familiar Swiss accent, to guide us through the RF module at the heart of the Baofeng, the SA818. For about $8 you can get one of these little marvels off AliExpress and have nearly all the important parts of a VHF or UHF radio — an SDR transceiver, a power amp, and all the glue logic to make it work.

In the video below, [Andreas] puts the SA818 module through its paces with the help of a board that pairs the module with a few accessories, like an audio amp and a low-pass RF filter. With a Raspberry Pi and a Python library to control the module, it’s a decent imitation of the functionality of a Baofeng. But that’s only the beginning. By adding a USB sound card to the Pi, the setup was able to get into every ham’s favorite packet radio system, APRS. There are a ton of other applications for the SA818 modules, some of which [Andreas] mentions at the end of the video. Pocket-sized repeaters, a ridiculously small EchoLink hotspot, and even an AllStar node in an Altoids tin.

Of course, if you want to get in on the fun, you’re going to need an amateur radio license. Don’t worry, it’s easy — we’ll help you get there.

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