Regen Receiver With Few Parts

August 30, 2021 by Al Williams 22 Comments

We like regenerative receivers. They perform well and they are dead simple to create. Example? [Radio abUse] modified a few existing designs and built a one-transistor receiver. Well, one transistor if you don’t count the dozens that are probably on the audio amplifier IC, but we won’t quibble. You can watch a video about the simple receiver — which looks good on a neatly done universal board — below.

The coil of #22 wire dominates the visual layout, and we imagine winding it might have been the most time-consuming part of the project. The layout would work with a single-sided PCB and would be a great board to produce by hand if you were inclined to develop that skill.

Regenerative receivers work by holding an amplifier just shy of oscillating at a certain frequency. This provides extremely high gain at a particular frequency which allows just a single stage to really pull in signals.

We were a little sad to find out there was a plan to tear the radio down to build something else. But, we suppose, that’s progress. We’d be tempted to make a module out of the audio amplifier and then keep the RF section intact. But, then again, we have a lot of partial projects like that gathering dust on the shelf, so maybe that’s not such a great idea.

While regenerative receivers aren’t the most common architecture today, they still have their place. The inventor, Edwin Armstrong, developed quite a bit of radio tech that we still use today.

3D Printering: Is Hassle-Free Bed Leveling Finally Here?

August 30, 2021 by Donald Papp 72 Comments

3D printers have come a long way over the past several years, but the process of bed leveling remains a pain point. Let’s take a look at the different ways the problem has been tackled, and whether recent developments have succeeded in automating away the hassle.

Anycubic Vyper 3D printer, front view — Anycubic Vyper, with an auto-leveling feature we decided to take a closer look at.

Bed leveling and first layer calibration tends to trip up novices because getting it right requires experience and judgment calls, and getting it wrong means failed prints. These are things 3D printer operators learn to handle with time and experience, but they are still largely manual processes that are often discussed in ways that sound more like an art than anything else. Little wonder that there have been plenty of attempts to simplify the whole process.

Some consumer 3D printers are taking a new approach to bed leveling and first layer calibration, and one of those printers is the Anycubic Vyper, which offers a one-touch solution for novices and experienced users alike. We accepted Anycubic’s offer of a sample printer specifically to examine this new leveling approach, so let’s take a look at the latest in trying to automate away the sometimes stubborn task of 3D printer bed leveling.

Continue reading “3D Printering: Is Hassle-Free Bed Leveling Finally Here?” →

Hacker Claims Honda And Acura Vehicles Vulnerable To Simple Replay Attack

August 30, 2021 by Lewin Day 25 Comments

Keyless entry has become a standard feature on virtually all cars, where once it was a luxury option. However, it’s also changed the way that thieves approach the process of breaking into a car. After recent research, [HackingIntoYourHeart] claims that many modern Honda and Acura vehicles can be accessed with a simple replay attack using cheap hardware.

It’s a bold claim, and one that we’d love to see confirmed by a third party. The crux of the allegations are that simply recording signals from a Honda or Acura keyfob is enough to compromise the vehicle. Reportedly, no rolling code system is implemented and commands can easily be replayed.

Given these commands control features like unlocking the doors, opening the trunk, and even remote starting the vehicle, it’s a concerning situation. However, it’s also somewhat surprising. Rolling code technology has been around for decades, and makes basic replay attacks more difficult. Range extender attacks that target keyfobs sitting inside homes or gas stations are more common these days.

Whether Honda has made a security faux pas, or if there’s something more at play here, remains to be seen. If you’ve got more information, or have been able to recreate the same hack on your own Honda, be sure to let us know.

Raspberry Pi And ESP32-S2 Team Up For MutantC_V4

August 30, 2021 by Tom Nardi 12 Comments

Back in 2019 we first came across the mutantC, an open source 3D printable Raspberry Pi handheld created by [rahmanshaber] that took more than a little inspiration from Sony’s VAIO ultra-mobile PCs (UMPCs) from the early 2000s. It was an impressive first effort, but it clearly had a long way to go before it could really be a practical mobile device.

Well after two years of development and three iterative versions of this Linux powered QWERTY slider, [rahmanshaber] is ready to show off the new and improved mutantC_v4. Outwardly it looks quite similar to the original version, with the notable addition of a tiny thumbstick and a pair of programmable buttons on the right side that can be used for input in addition to the touch screen. But inside it’s a whole other story, with so many changes and improvements that we hardly even know where to start.

Inside the mutantC_v4, showing off the ESP32-S2

Probably the most notable improvement is the addition of an ESP32-S2, specifically a bare ESP-12K module, to the main PCB. Previous versions of the hardware used an Arduino Pro Micro to interface with all the hardware, but the added horsepower of the ESP32 should come in handy with the array of sensors, controls, and NeoPixels that [rahmanshaber] has tasked the chip with. There’s even a buzzer and a coin-style vibration motor in there to provide some feedback to the user. While the board has changed significantly, it still retains compatibility with the Pi Zero, 2, 3, and 4.

Another notable addition is the expansion connector on the bottom of the handheld that has pins for I2C, UART, and 3.3 V. In the video below, [rahmanshaber] mentions that this feature was previously implemented with a standard 2×6 female header block, but is now using a far slimmer female USB-C port. We do wonder if it’s not a bit confusing to have this faux-USB port right next to the real one that’s actually used to charge the system, but with such cramped quarters occasionally you’ve got to make some tough decisions like that.

It’s quite inspiring to see how [rahmanshaber] has honed his skills since releasing the first version of the mutantC. The 3D printed parts and PCBs have matured considerably over the last two years, showing how quickly a dedicated hobbyist can advance their abilities. The most recent version has been entered in the 2021 Hackaday Prize. But the show isn’t over yet, as we hear v5 of this impressive handheld may tackle the Raspberry Pi 4 Compute Module.

Continue reading “Raspberry Pi And ESP32-S2 Team Up For MutantC_V4” →

Dyson Award Goes To Emergency Medical Device For Treating Stab Wounds

August 29, 2021 by Al Williams 68 Comments

[Joseph Bentley] must be one of those people who sees opportunity in problems. He had several friends who were victims of knife attacks, so he developed REACT, a device that would allow police or other first responders to quickly help victims of stab wounds. The project won the Dyson award and you can see the video about it, below.

The device has two parts: a medical-grade silicone sleeve and a handheld actuator. The sleeve actually inserts into the stab wound and the actuator pressurizes the sleeve based on the location of the wound. The actuator has a user interface to allow the operator to select the area of the body affected.

We don’t know much about emergency medicine, but apparently, the current method is to apply pressure externally and this doesn’t do much for internal bleeding. The sleeve solves that and [Bentley] thinks the device can save many lives if brought to market. Of course, getting a medical device actually on the market is a long road fraught with regulatory peril. We hope the Dyson award will help [Bentley] get the product in the hands of people who can use it to good purpose.

We are very interested in replacing damaged body parts, but saving people from losing body parts or life is good, too. Sometimes, just calling for help is worthwhile.

Continue reading “Dyson Award Goes To Emergency Medical Device For Treating Stab Wounds” →

Nokia LCD Goes Transparent For Hands-Free Reminders

August 29, 2021 by Tom Nardi 1 Comment

These days everyone’s excited about transparent OLED panels, but where’s the love for the classic Nokia 5110 LCD? As the prolific [Nick Bild] demonstrates in his latest creation, all you’ve got to do is peel the backing off the the late 90s era display, and you’ve got yourself a see-through cyberpunk screen for a couple bucks.

In this case, [Nick] has attached the modified display to a pair of frames, and used an Adafruit QT Py microcontroller to connect it to the ESP32 powered ESP-EYE development board and OV2640 camera module. This lets him detect QR codes within the wearer’s field of vision and run a TensorFlow Lite neural network right on the hardware. Power is provided by a 2000 mAh LiPo battery running through an Adafruit PowerBoost 500.

The project, intended to provide augmented reality reminders for medical professionals, uses the QR codes to look up patient and medication information. Right now the neural network is being used to detect when the wearer has washed their hands, but obviously the training model could be switched out for something different as needed. By combining these information sources, the wearable can do things like warn the physician if a patient is allergic to the medication they’re currently looking at.

Relevant information and warnings are displayed on the Nokia LCD, which has been placed far enough away from the eye that the user can actually read the text; an important design consideration that [Zach Freedman] demonstrated with his (intentionally) illegible wearable display a few weeks back. That does make the design a bit…ungainly, but at least you don’t have to worry about hand-cutting your optics

Hackaday Links: August 29, 2021

August 29, 2021 by Dan Maloney 14 Comments

If you thought that COVID-19 couldn’t possibly impact space travel, think again. The ongoing pandemic is having unexpected consequences for companies like SpaceX, who are worried about liquid oxygen shortages due to increased demand for medical oxygen. Massive amounts of liquid oxygen are used as the oxidizer for each rocket launch, of course, as well as in hospitals, which have giant tanks of liquid oxygen somewhere on site. Whether destined for space or for patient care, liquid oxygen comes from cryogenic separation plants, and SpaceX fears that they would have to delay or even cancel launches if manufacturers can’t keep up with demand and have to prioritize their healthcare customers. We’re actually not sure if this is a concern, though, since there are usually separate supply chains for medical and industrial gasses. Then again, we’d suspect a rocket engine might prefer to breathe ultra-pure LOX too.

Speaking of space, if you want to be an astronaut, perhaps the first skill you need to develop is patience. Not only might your ride not be ready to go when you are, but at least in the EU, you’ve got a long line of applicants in front of you. The European Space Agency announced this week that they’re working through a backlog of 23,000 applications for astronaut positions. About 20% of those will apparently be dropped in the pre-screening process, but the rest will (eventually) get an invitation to a full-day test at one of the ESA’s facilities. We imagine the attrition rate from there increases dramatically; either that or the ESA intends to hire a lot of astronauts.

Back here on Earth, Google this week did what it seems to do a lot of, and killed off one of its popular apps. This time the victim is the Android Auto phone app, although we have to admit the whole thing is confusing. The app allows you to connect your phone to the infotainment system in a compatible late-model car, letting you access all your apps without having to fiddle with your phone while driving. But Google also had an app that offered the same experience directly on the phone, for cars without a compatible display. As far as we can tell, the on-phone app is the only thing that’s going away in Android 12; the app for in-car displays will continue to be supported. Former users of the phone-only app are being encouraged to migrate to Google Assistant’s Driving Mode. Or, you know, you could just drive the car instead.

So your brand-new video card is running hot, and you can’t figure out why. At your wit’s end, you crack open the card’s cover and find the reason — a somewhat suspicious-looking foreign object. That’s what happened to Antony ter Horst and his Nvidia RTX 3090, which had a finger cot wedged inside it. It would appear to have slipped off the finger of some assembly worker, and it was clearly interfering with heat flow inside the card. Antony posted the pictures on reddit, which of course found much humor in the finger cot’s resemblance to another latex object. For our part, it put us in mind of some other stories of foreign objects found in common products — there’s a reason why we always check a loaf of bread before using it.

And finally, in a lot of ways YouTube has become the new “vast wasteland” of useless content. But like television before it, there are occasional gems to be found, especially to those of us who love to learn a little something as we watch. And so when we stumbled upon a video with the title “Hot Tap and Stopple Bypass at Smoky Lake” we had to check it out just to find out what each of those words meant. It turned out to be a great video on pipeline construction methods. The “hot tap” refers to cutting into the pipeline, containing high-pressure diluted bitumen from the shale oil fields near Smoky Lake, Alberta, without interrupting the flow of product. The “stopple” is a device that can be threaded into the pipe to permanently seal it, diverting the flow to a newly installed bypass. The whole process is fascinating, so we thought we’d share. Enjoy.

Continue reading “Hackaday Links: August 29, 2021” →