Reverse Engineering A Better Night’s Sleep

June 6, 2023 by Dan Maloney 8 Comments

All you want is a decent night’s sleep, so you decide to invest in one of those fancy adjustable beds. At first, it’s fine — being able to adjust the mattress to your needs on the fly is a joy, and yet…something isn’t quite right. Something nags at you every night, thwarting your slumber and turning your dreams of peaceful sleep into a nightmare once you realize your bed has locked you into a vertically integrated software ecosystem from which there’s no escape.

Or is there? That’s what [Chris Laplante] wanted to know, and why he reverse-engineered his Tempur-Pedic remote control. As many products these days do, his bed was touted as having an Android application for smartphone adjustability, but alas, the app hasn’t been updated since 2014 (!) and doesn’t appear to work on modern phones. [Chris] decided to take matters into his own hands and build a gateway to talk to the bed using its native RF protocol.

Most good reverse engineering stories start with research, and this one is no exception. Digging into the FCC database revealed a wealth of clues, such as the frequency — 433-MHz ISM band, no surprise — and even spectrum analyzer screenshots of the remote’s signals. A HackRF One revealed more about the signals, but it turned out that sniffing in on the SPI bus between the microcontroller and the Si4431 RF transceiver with a Salae logic analyzer was more fruitful, allowing him to dig into the packet structure.

The engineers at Tempur-Pedic threw quite a few challenges at [Chris], like an application-level CRC in addition to the CRC used by the Si4431, and interesting complications to control the massage features of the bed. In the end, [Chris] managed to get a pretty complete snapshot of the conversation between the bed and the remote, and is now in the process of building a gateway that’ll actually connect to his phone, plus integrate into his home automation system. We’re looking forward to updates on that.

Before You Sudo Rm -rf /, Take Some Precautions

April 21, 2023 by Bryan Cockfield 40 Comments

Maintaining or administering a computer system remotely is a common enough task these days, but it’s also something that can go sideways on you quickly if you aren’t careful. How many of us are guilty of executing a command, having it fail, and only then realizing that we weren’t connected to the correct computer at all? [Callan] occasionally has this issue as well, but in at least one instance, he deleted all of the contents of the wrong server by mistake. To avoid that mistake again, he uses color codes in the command line in a fairly unique way.

The solution at first seems straightforward enough. Since the terminal he’s using allows for different colors to be displayed for the user and hostname on the bash prompt, different text and background colors are used for each server. The only problem with this is that his friends also have access to these servers, and one of them is red/green colorblind, which led to another near-catastrophic mix-up. To ensure no edge cases are missed, [Callan] built a script which runs on every new server he spins up which selects two random colors, checks that they contrast well with each other, don’t create problems for the colorblind, and then applies them to the bash prompt.

For a problem most of us have had at some point or another, it’s a fairly elegant solution that helps ensure we’re sending the right commands to the right computer. This adds a layer of automation to the process and, while some color combinations do look similar, there are enough to help out most of us in some way, especially since he has released the source code on his GitHub page. For other helpful server administration tips, we’d recommend the Linux-Fu article about deploying your own dynamic DNS.

Hacking An Apartment Garage Door With New Remotes

April 19, 2023 by Lewin Day 28 Comments

[Old Alaska] had a problem. He needed a second remote for his apartment garage door, but was quoted a fee in the hundreds of dollars for the trouble of sourcing and programming another unit. Realizing this was a rip-off given the cheap hardware involved, he decided to whip up his own sneaky solution instead.

It’s a simple hack, cheap and functional. An RF-activated relay with two remotes was sourced online for the princely sum of $8. [Old Alaska] then headed down to the equipment cabinet in the garage, opening the lock with the side of his own car key. He then wired the relay in parallel with the existing manual pushbutton for activating the garage door.

Sometimes, a hack doesn’t have to be complicated to be useful. Many of us might have jumped straight to trying to capture and emulate the existing remote’s radio signals. There was really no need. With physical access, [Old Alaska] was able to simply wire in his own remote entry setup himself.

We’ve seen similar hacks before, albeit achieved with SIGINT methods instead. Video after the break.

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Hackaday Links: January 8, 2023

January 8, 2023 by Dan Maloney 12 Comments

Something odd is afoot in the mountains around Salt Lake City, Utah, at least according to local media reports of remote radio installations that have been popping up for at least the past year. The installations consist of a large-ish solar panel, a weatherproof box full of batteries — and presumably other electronics, including radios — and a mast bearing at least one antenna. Local officials aren’t quite sure who these remote setups belong to or what they’re intended to do, but the installations obviously represent a huge investment in resources.

The one featured in the story was located near the summit of Twin Peaks, which is about 11,000 feet (3,300 meters) in elevation, which with that much gear was probably a hell of a hike. Plus, the owner took great pains to make sure the site would withstand the weather, with antenna mast guy wires that must have required lugging a pretty big drill up with them. There aren’t any photos of the radios in the enclosure, but one photo shows a 900-MHz LORA antenna, while another shows what appears to be a panel antenna, perhaps pointing toward another site. So maybe a LORA mesh network? Some comments in the Twitter thread show most people are convinced this is a Helium crypto mining rig, but the Helium Explorer doesn’t show any hotspots listed in that area. Either way, the owners are out of luck, since their gear is being removed if it’s on public land.

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Start Your Engines: The FPV Contest Begins Now!

November 22, 2022 by Elliot Williams 15 Comments

There are places that you can go in person, but for everything else, there’s FPV. Whether you’re flying race quads, diving the depths in a yellow submarine, or simply roving the surface of the land, we want to see your builds. If it’s remote controlled, and you feel like you’re in the pilot’s seat, it’s FPV.

When you say “first person view” many of you will instinctively follow up with “flight” or “drone”. But given the ease of adding a camera and remote control to almost any vehicle, there’s no reason to only fly the FPV skies. (Of course, we want to see your crazy quadcopter builds too.)

We went looking for a few less-traditional examples to whet your appetite, and we found a lot. There are super-cute FPV bots for indoors and more robust tanks for cruising around the neighborhood. In the summer, you’ll probably need an FPV lawnmower, and for the winter, naturally, an FPV snowblower or a budget-friendly FPV snow-boat. Or skip the outdoors entirely and terrorize the pool with an FPV sub.

This contest isn’t exclusively about the vehicles either. If you’re working on the tech that makes FPV possible, we want you to enter. For instance, this simple quad/drone tracker will help keep your video feed running and your mind on flying. This cockpit will make the immersion more complete. And nobody likes the jello-cam effect that excess vibration can cause, so we’d like to see camera hacks as well.

And of course, your quads. Is your FPV quad too fast, too light, or does it fly too far? Show us. The contest starts now and runs until Jan 3, 2023, and there are three $150 shopping sprees courtesy of Digi-Key on the line. Get hacking!

IR Remote Transforms To RF

March 21, 2022 by Al Williams 13 Comments

Most consumer remote controls operate using infrared light. This works well assuming the piece of equipment has a line of sight to the remote. But if you have, say a receiver in a cabinet or closet, the IR remote signal can’t reach the sensor. Some equipment has remote receivers that you can leave poking out, but it is still not very handy. That’s why some equipment now uses RF remotes. [Xtropie] used a pair of inexpensive 433 MHz RF modules to convert an IR system to RF. You can see a short video about the project below.

We might have been tempted to simply put an IR LED on the receiver so it could feed IR into the device sensor, but [Xtropie] took a different approach. He found the IR sensor and tied the RF receiver directly into its output. It seems to work, but we probably would have removed the IR sensor to make sure there were no conflicts.

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IR Translator Makes Truly Universal Remote

February 10, 2022 by Bryan Cockfield 19 Comments

Universal remotes are a handy tool to have around if you have many devices that would all otherwise have their own remote controls. Merging them all into a single device leads to less clutter and less frustration, but they are often not truly “universal” as some of them may not support every infrared device that has ever been built. If you’re in a situation like that it’s possible to build a truly universal remote instead, provided you have a microcontroller and a few infrared LEDs on hand.

This was the situation that [Matt] found himself in when his Amazon Fire TV equipment control feature didn’t support his model of speakers. To get around this he programmed an Arduino to essentially translate the IR codes from the remote and output a compatible set of codes to the speakers.This requires both an IR photodiode and an IR LED but little else other than the codes for the remote and the equipment in question. With that all set up and programmed into the Aruino, [Matt]’s remote is one step closer to being truly “universal”.

While [Matt] was able to make use of existing codes in the Arduino library, it is also possible to capture the codes required manually by pointing a remote at a photodiode and programming a microcontroller to capture the codes that you need. [Matt] used a Raspberry Pi to do this when debugging this project, but we’ve also seen this method used with a similar build which uses an ESP8266 to control an air conditioner via its infrared remote control capabilities.

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