Factory Laptop With IME Disabled

Unfortunately not all consumers place high value on the security of their computers, but one group that tends to focus on security are businesses with a dedicated IT group. When buying computers for users, these groups tend to have higher demands, like making sure the Intel Management Engine (IME) has been disabled. To that end, Reddit user [netsec_burn] has outlined a pretty simple method to where “normal people” can purchase one of these IME-disabled devices for themselves.

For those unfamiliar with the IME, it is a coprocessor on all Intel devices since around 2007 that allows access to the memory, hard drive, and network stack even when the computer is powered down. Intel claims it’s a feature, not a bug, but it’s also a source of secret, unaudited code that’s understandably a desirable target for any malicious user trying to gain access to a computer. The method that [netsec_burn] outlined for getting a computer with the IME disabled from the factory is as simple as buying a specific Dell laptop, intended for enterprise users, and selecting the option to disable the IME.

Of course Dell warns you that you may lose some system functionality if you purchase a computer with the IME disabled, but it seems that this won’t really effect users who aren’t involved in system administration. Also note that this doesn’t remove the management engine from the computer. For that, you’ll need one of only a handful of computers made before Intel made complete removal of the IME impossible. In the meantime, it’s good to see that at least one company has a computer available that allows for it to be disabled from the factory.

RF Modulation: Crash Course For Hackers

When you’re looking to add some wireless functionality to a project, there are no shortage of options. You really don’t need to know much of the technical details to make use of the more well-documented modules, especially if you just need to get something working quickly. On the other hand, maybe you’ve gotten to the point where you want to know how these things actually work, or maybe you’re curious about that cheap RF module on AliExpress. Especially in the frequency bands below 1 GHz, you might find yourself interfacing with a module at really low level, where you might be tuning modulation parameters. The following overview should give you enough of an understanding about the basics of RF modulation to select the appropriate hardware for your next project.

Three of the most common digital modulation schemes you’ll see in specifications are Frequency Shift Keying (FSK), Amplitude Shift Keying (ASK), and LoRa (Long Range). To wrap my mechanically inclined brain around some concepts, I found that thinking of RF modulation in terms of pitches produced by a musical instrument made it more intuitive.

And lots of pretty graphs don’t hurt either. Signals from two different RF dev boards were captured and turned into waterfall and FFT plots using a $20 RTL-SDR dongle. Although not needed for wireless experimentation, the RTL-SDR is an extremely handy debugging tool, even to just check if a module is actually transmitting. Continue reading “RF Modulation: Crash Course For Hackers”

Open-Source Medical Devices Hack Chat

Join us on Wednesday, January 29 at noon Pacific for the Open-Source Medical Devices Hack Chat with Tarek Loubani!

In most of the developed world, when people go to see a doctor, they’re used to seeing the latest instruments and devices used. Most exam rooms have fancy blood pressure cuffs, trays of shiny stainless steel instruments, and a comfortable exam table covered by a fresh piece of crisp, white paper. Exams and procedures are conducted in clean, quiet places, with results recorded on a dedicated PC or tablet.

Such genteel medical experiences are far from universal, though. Many clinics around the world are located in whatever building is available, if they’re indoors at all. Supplies may be in chronically short supply, and to the extent that the practitioners have the instruments they need to care for patients, they’ll likely be older, lower-quality versions.

Tarek Loubani is well-versed in the practice of medicine under conditions like these, as well as far worse situations. As an emergency physician and researcher in Canada, he’s accustomed to well-appointed facilities and ample supplies. But he’s also involved in humanitarian relief, taking his medical skills and limited supplies to places like Gaza. He has seen first-hand how lack of the correct tools can lead to poor outcomes for patients, and chose to fight back by designing a range of medical devices and instruments that can be 3D-printed. His Glia Project has free plans for a high-quality stethoscope that can be built for a couple of dollars, otoscopes and pulse oximeters, and a range of surgical tooling to make the practice of medicine under austere conditions a little easier. Continue reading “Open-Source Medical Devices Hack Chat”

Clock Uses Custom LED Displays To Keep Myst Time

The Myst fans in the audience will love this project because it displays the 25-hour timekeeping system of the D’ni. The hardware hackers will lean a little closer to their screen because it does so with custom made 25-segment LEDs, and the precision obsessed will start breathing heavily when they hear it maintains an accuracy of 0.001 seconds. As for which of those camps creator [Mike Ando] most identifies with, we can’t say. But we definitely respect his style.

We’ll spare you the in-depth description of the base-25 number system apparently used in the Myst franchise. If you’re interested enough you can click on through to the project’s Hackaday.io page and learn how to actually read the clock. Presumably you’ll then come back here and leave your comment in Klingon.

Let’s instead jump right to the part that really gets us excited, those custom displays. To create them, [Mike] cut the face out of black acrylic with a laser, and filled each void with a mixture of clear resin and very fine gypsum plaster. Getting the mix right can be a little finicky as the plaster can clump up, but the end result diffuses the light nicely. The acrylic front panel and a couple of cardboard “gaskets” to keep the light from leaking onto adjacent segments is then stacked on top of a PCB with corresponding 0603 SMD LEDs.

Beyond the soul-crushing number of wires required to hook everything up internally, the rest of the project is relatively straightforward. It uses a WeMos D1 Mini to connect to the WiFi network and pull the current time down from the geographically closest NTP server every couple of hours. Rather than putting a temperature controlled oscillator on the board, [Mike] has decided to pin his accuracy on a constantly on Internet connection and aggressive synchronizations.

From impressive curved bar graph modules to displays segmented with household items, we’ve seen our fair share of custom indicators. But we have to admit that building 25-segment LED displays for the alphabet of a fictional interstellar species sets the bar pretty high.

Continue reading “Clock Uses Custom LED Displays To Keep Myst Time”

Lead-Free Solder Alloys: Their Properties And Best Types For Daily Use

Lead-free solder alloys have been around for as long as people have done soldering, with sources dating back about 5,000 years. Most of these alloys were combinations like copper-silver or silver-gold and used with so-called hard soldering. That’s a technique still used today to join precious and semi-precious metals together. A much more recent development is that of soldering electronic components together, using ‘soft soldering’, which entails much lower temperatures.

Early soft soldering used pure tin (Sn), yet gradually alloys were sought that would fix issues like thermal cycling, shock resistance, electron migration, and the development of whiskers in tin-based alloys. While lead (Pb) managed to fill this role for most soldering applications, the phasing out of lead from products, as well as new requirements for increasingly more fine-pitched components have required the development of new solder alloys that can fill this role.

In this article we’ll be looking at the commonly used lead-free solder types for both hobby and industrial use, and the dopants that are used to improve their properties.

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Raspberry Pi 4 Benchmarks: 32- Vs 64-bits

[Matteo] bought a new Raspberry Pi 4. Why not? You get a quad-core ARM processor, up to 4 GB of RAM, and a gigabit Ethernet port for $35 $35-55. However, the default operating system is still a 32-bit system and doesn’t take advantage of the Pi 4’s 64-bit capable CPU. So he installed a light version of 64-bit Debian and ran some benchmarks for the Raspberry Pi 4 running both 32-bit and 64-bit operating systems.

It really shouldn’t be surprising that the 64-bit OS did better in nearly every test. If anything is surprising, it may be that the difference is so pronounced. Some of the benchmarks, like Dhrystones, probably don’t relate much to real-life usage. But some things, like computing a hash, is something you probably do pretty often in normal usage, and the timing difference is pronounced.

Continue reading “Raspberry Pi 4 Benchmarks: 32- Vs 64-bits”

New Part Day: SK6812 Mini-E. A Hand Solderable Neopixel Compatible LED!

Normally when we give you a New Part Day piece, it concerns a component that you will have never seen before. The subject of this find by [Robert Fitzsimons] then is a slight departure from that norm, given that the SK6812 Mini-E is a WS2812 or Neopixel compatible multi-colour LED of a type that has been available for a while now.

What makes this component new though is its packaging. The Mini-E variant of the SK6812 only appeared last year and has now found its way through to smaller order quantities on AliExpress. Its special feature is that it has a set of flat leads rather than the usual pads on the underside of the package. This means that unlike its predecessors it is readily hand solderable, as he demonstrates by attaching a set of leads to one.

The leads emerge halfway up the side of the device, which seems designed to be mounted recessed within a PCB hole. He demonstrates this with a piece of stripboard, and remarks that they would make a good choice for many small projects such as Shitty Add-On boards.

We’ve touched the leadless SK6812s a few times before, along the way remarking that in some respects they are better than the WS2812 they follow.

Continue reading “New Part Day: SK6812 Mini-E. A Hand Solderable Neopixel Compatible LED!”