Sketchy Logg Dogg Logging Robot Remote Control Hacking

February 20, 2024 by Maya Posch 9 Comments

When we last left [Wes] amidst the torn-open guts of his Logg Dogg logging robot, he had managed to revitalize the engine and dug into the hydraulics, but one big obstacle remained: the lack of the remote control unit. In today’s installment of the Logg Dogg series, [Wes] summarizes weeks of agony over creating a custom circuit based around a microcontroller, a joystick and a lot of relays and other bits and pieces to drive the solenoids inside the logging machine that control the hydraulics.

Giving the remote controller a bench test before connecting to the logging robot (Credit: Watch Wes Work)

Most of the struggle was actually with the firmware, as it had to not only control the usual on/off solenoids, but also a number of proportional solenoid valves which control things like the track speed by varying the hydraulic flow to the final drives.

This requires a PWM signal, which [Wes] generated using two MOSFETs in a closed-feedback system, probably because open loop controls with multi-ton hydraulic machinery are not the kind of excitement most people look forward to.

Ultimately he did get it sorted, and was able to take the Logg Dogg for its first walk since being rescued from a barn, which both parties seemed to rather enjoy. The background details of this machine and the project can be found in our first coverage.

We’re looking anxiously forward to the next episode, where the controller goes wireless and the sketchiness gets dialed down some more.

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Installing SteamOS And Windows On A Google Meet Video Conference Computer

February 19, 2024 by Maya Posch 20 Comments

The Lenovo Meet is a collaboration with Google to bring Google Meet to customers in a ready to install kit for conference rooms and similar. Also called the Google Meet Series One, it features a number of cameras, speakers, display and more, along with the base unit. It is this base unit that [Bringus Studios] on YouTube tried to install a different OS capable of running Steam games on in a recent video. Along the way many things were learned about this device, which is – unsurprisingly – just another ChromeOS box.

After removing the rubber bottom (which should have been softened with a hot air gun to prevent damage), the case can be opened with some gentle prying to reveal the laptop-like innards. Inside are an 8th gen Intel CPU (i7-8550U @ 1.8 GHz), a 128 GB SATA M.2, 2 GB DDR4 RAM, along with 2 more GB of DDR4 a MicroSD slot and a Google Coral DA1 TPU on the bottom of the mainboard. It should be easy to install Linux, Windows, etc. on this other than for the ChromeOS part, which locks down the non-UEFI BIOS firmware.

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WoWMIPS: A MIPS Emulator For Windows Applications

February 17, 2024 by Maya Posch 12 Comments

When Windows NT originally launched it had ports to a wide variety of platforms, ranging from Intel’s x86 and i860 to DEC’s Alpha as well as the MIPS architecture. Running Windows applications written for many of these platforms is a bit tricky these days, which [x86matthew] saw as a good reason to write a MIPS emulator. This isn’t just any old emulator, though. It maps 32-bit Windows applications targeted at the MIPS R4000 CPU to an x86 CPU instead. Since both platforms run in a little-endian, 32-bit mode, this theoretically should be a walk in the park.

The use of the Windows PE executable format is also the same, so the first task was to figure out how to load the MIPS PE binary in a way that made sense for an x86 platform. This involved some reverse-engineering of the MIPS ntdll.dll file to figure out how relocations on that platform were handled. Following this, the mapping of the instructions of the R4000 CPU to the (CISC) x86 ISA was pretty easy. Only Floating Point Unit (FPU) support was left as a future challenge. Memory access was left as direct access, meaning no sandboxing or isolation, for simplicity’s sake.

The final task was mapping the native API calls, which call almost directly into the underlying host Windows OS’s API, with a bit of glue logic. With all of this done, Windows NT applications originally written for 1990s MIPS ran just fine on a modern-day x86_64 PC running Windows — as long as you don’t need an FPU (for now).

An image of a cave drawing of horned cow. There is another one coming up behind it as well. There are four dots as described by the researchers on the main cow's back.

Writing – So Easy A Caveperson Could Do It

February 13, 2024 by Navarre Bartz 10 Comments

We modern humans tend to take writing for granted, and often forget that like any other technology, somebody had to invent it. Researchers from Cambridge believe they’ve determined the purpose of one of the earliest writing beta-tests.

Examining a database of images taken in caves throughout Europe and dated to the Upper Paleolithic, the researchers found “three of the most frequently occurring signs—the line <|>, the dot <•>, and the <Y>—functioned as units of communication.”

It appears the <|> and <.> symbols when “in close association with images of animals” denote time relating to lunar months of the year, starting with spring as the new year. The <Y> symbol appears to carry the meaning <To Give Birth> allowing early people a way to tell others information about the prey of a region, which would be pretty handy when hunting and gathering are your only options for food.

We’ve covered other ancient technologies like storytelling and abrasives. If you’re curious what the climate was like for our ancestors, perhaps paleoclimatology will tickle your fancy.

IoT Air Purifier Makes A Great Case Study In Reverse Engineering

February 6, 2024 by Dan Maloney 10 Comments

Here at Hackaday, about the only thing we like more than writing up tales of reverse engineering heroics is writing up tales of reverse engineering heroics that succeed in jailbreaking expensive widgets from their needless IoT dependency. It’s got a real “stick it to the man” vibe that’s hard to resist.

The thing is, we rarely see a reverse engineering write-up as thorough as the one [James Warner] did while integrating an IoT air purifier into Home Assistant, so we just had to make sure we called this one out. Buckle up; it’s a long, detailed post that really gets down into the weeds, but not unnecessarily so. [James] doesn’t cloud-shame the appliance manufacturer, so we can’t be sure who built this, but it’s someone who thought it’d be a swell idea to make the thing completely dependent on their servers for remote control via smartphone. The reverse engineering effort started with a quick look at the phone app, but when that didn’t pay off in any useful way, [James] started snooping on what the device was talking about using Wireshark.

One thing led to another, wires were soldered to the serial pins on the ESP32 on the purifier’s main board, and with the help of a FlipperZero as a UART bridge, the firmware was soon in hand. This gave [James] clues about the filesystem, which led to a whole Ghidra side quest into learning how to flash the firmware. [James] then dug into the meat of the problem: figuring out the packet structure used to talk to the server, and getting the private key used to encrypt the packets. This allowed a classic man-in-the-middle attack to figure out the contents of each packet and eventually, an MQTT bridge to let Home Assistant control the purifier.

If it sounds like we glossed over a lot, we know — this article is like a master class on reverse engineering. [James] pulled a lot of tools out of his kit for this, and the write-up is clear and concise. You may not have the same mystery fan to work with, but this would be a great place to start reverse engineering just about anything.

Thanks to [ThoriumBR] for the tip.

A white male in a green shirt sitting next to a tall rectangular robot made of green and black components with an aluminum frame. In front of him are a variety of components from several windshield wiper motor assemblies. Casings, gearboxes, and the like are strewn across the wooden table.

A Wiper Motor 101

February 2, 2024 by Navarre Bartz 22 Comments

Need a powerful electric motor on the cheap? [Daniel Simu] and his friend [Werner] show us the ins and outs of using windshield wiper motors.

Through many examples and disassembled components, the duo walk us through some of the potential uses of wiper motors to power a project. Some of the nuggets we get are the linear relationship of torque to current (10-15A max) and speed to voltage (12-15V DC) on these units, and some of the ways the wiring in these motors is a little different than a simple two wire DC motor.

They also discuss some of their favorite ways to control the motors ranging from a light switch to an Arduino. They even mention how to turn one into a big servo thanks to a project on Hackaday.io and a few modifications of their own. [Simu] also discusses some of the drawbacks of wiper motors, the most evident being that these motors use nylon gears which are prone to stripping or failing in other ways when subjected to high torque conditions for too long.

If you recognize [Simu], it may be from his robotic acrobat built with wiper motors. Want to see some more wiper motor hacks? How about a 3D scanner or making sure your wipers always keep the beat?

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Hacking A Xiaomi Air Purifier’s Filter DRM To Extend Its Lifespan

January 26, 2024 by Maya Posch 10 Comments

When [Unethical Info] was looking at air purifiers a while back, their eye fell on a Xiaomi 4 Pro, with a purchase quickly made. Fast-forward a while and suddenly the LCD on top of the device was showing a threatening ‘0% filter life remaining’ error message. This was traced back to an NFC (NTAG213) tag stuck to the filter inside the air purifier that had been keeping track of usage and was now apparently the reason why a still rather clean filter was forcibly being rejected. Rather than give into this demand, instead the NFC tag and its contents were explored for a way to convince it otherwise, inkjet cartridge DRM-style.

While in the process of reverse-engineering the system and doing some online research, a lucky break was caught in the form of earlier research by [Flamingo Tech] on the Xiaomi Air Purifier 3, who had obtained the password-generating algorithm used with the (password-locked) NFC tag, along with the target area of the filter’s NFC tag to change. Using the UID of the NFC tag, the password to unlock the NFC tag for writing was generated, which requires nothing more than installing e.g. ‘NFC Tools’ on an NFC-capable Android/iOS smartphone to obtain the tag’s UID and reset the usage count on the filter.

A password generating tool is provided with the [Unethical Info] article, and this approach works across a range of Xiaomi air purifiers, making it an easy fix for anyone who owns such a device but isn’t quite ready yet to shell out the big bucks for a fresh DRM-ed filter. This approach also saves one from buying more NFC tags, which was the case with the previous solution.