Bypassing Airpods Hearing Aid Georestriction With A Faraday Cage

November 15, 2024 by Maya Posch 54 Comments

When Apple recently announced the hearing aid feature on their new AirPods Pro 2, it got the attention of quite a few people. Among these were [Rithwik Jayasimha] and friends, with [Rithwik] getting a pair together with his dad for use by his hard-of-hearing grandmother. That’s when he found out that this feature is effectively limited to the US and a small number of other countries due them being ‘regulated health features’, per Apple. With India not being on the approved countries list and with no interest in official approval legalities, [Rithwik] set to work to devise a way to bypass this restriction.

As noted in the blog post, the primary reason for using AirPods here instead of official hearing aids is due to the cost of the latter, which makes them a steal for anyone who is dealing with mild to moderate hearing loss. Following the official Hearing Aid feature setup instructions requires that your location is detected as being in an approved country. If it is, the Health App (on iOS 18.1) will popup a ‘Get Started’ screen. The challenge was thus to make the iOS device believe that it was actually in the FDA-blessed US and not India.

Merely spoofing the location and locale didn’t work, so the next step was to put the iOS device into a Faraday cage along with an ESP32 that broadcast California-based WiFi SSIDs. Once the thus treated iPad rebooted into the US, it could be used to enable the hearing aid feature. Next [Rithwik] and friends created a more streamlined setup and procedure to make it possible for others to replicate this feat.

As also noted in the blog post, the Hearing Aid feature is essentially a specially tuned Transparency mode preset, which is why using AirPods for this feature has been a thing for a while, but with this preset it’s much better tuned for cases of hearing loss.

Repairing The Questionable £25,000 Tom Evans Audiophile Pre-Amp

November 14, 2024 by Maya Posch 123 Comments

One of the power supply boards in the Tom Evans Mastergroove SR MkIII preamplifier. (Credit: Mend it Mark, YouTube)

It’s not much of a secret that in the world of ‘audiophile gear’ there is a lot of snake oil and deception, including many products that are at best of questionable value. The Tom Evans Mastergroove SR mkIII preamplifier is one example of this, as [Mark] from the Mend it Mark YouTube channel found in a recent video when he got one to repair which the manufacturer claimed ‘could not be fixed’. This marvel of audio engineering provides amplification for record players, for the low-low price of only twenty-five thousand quid, or about 29.000 US bucks. So what’s inside one of these expensive marvels?

Claiming to be a high-end unit, with only ten units produced per year, you’d expect a gold-plated PCB with excellent noise isolation. The unit does come with an absolutely massive external power supply that dwarfs the preamplifier itself, but the real surprise came after opening up the unit itself to take a peek at the damage, some of which was caused by transport.

As it turns out, the inside of the preamplifier consists out of four stacks of rather cheap, home-made looking boards with what looks like improvised RF shielding in the form of bare PCBs and filed-off markings on many parts. In between the rat’s nest of wiring running everywhere, [Mark] had to trace the broken channel’s wiring, creating a full repair manual in the process. Along the way one of the opamp boards was found to be defective, courtesy of a single shorted tantalum capacitor.

With the tantalum capacitor replaced, [Mark] had repaired the unit, but even though the preamplifier isn’t terribly designed, the illusion of its price tag has been shattered worse than the contents of a parcel kicked across the parking lot by the Royal Mail.

Thanks to [Jim] for the tip.

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The Life Cycle Of Nuclear Fission Fuel: From Stars To Burn-Up

November 14, 2024 by Maya Posch 48 Comments

Outdone only by nuclear fusion, the process of nuclear fission releases enormous amounts of energy. The ‘spicy rocks’ that are at the core of both natural and artificial fission reactors are generally composed of uranium-235 (U-235) along with other isotopes that may or may not play a role in the fission process. A very long time ago when the Earth was still very young, the ratio of fissile U-235 to fertile U-238 was sufficiently high that nuclear fission would spontaneously commence, as happened at what is now the Oklo region of Gabon.

Although natural decay of U-235 means that this is unlikely to happen again, we humans have learned to take uranium ore and start a controlled fission process in reactors, beginning in the 1940s. This can be done using natural uranium ore, or with enriched (i.e. higher U-235 levels) uranium. In a standard light-water reactor (LWR) a few percent of U-235 is used up this way, after which fission products, mostly minor actinides, begin to inhibit the fission process, and fresh fuel is inserted.

This spent fuel can then have these contaminants removed to create fresh fuel through reprocessing, but this is only one of the ways we have to extract most of the energy from uranium, thorium, and other actinides like plutonium. Although actinides like uranium and thorium are among the most abundant elements in the Earth’s crust and oceans, there are good reasons to not simply dig up fresh ore to refuel reactors with.

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Smart Thermostats Pitched For Texas Homes To Relieve Stressed Grid

November 14, 2024 by Maya Posch 86 Comments

It’s not much of a secret that Texas’ nearly completely isolated grid is in a bit of a pickle, with generating capacity often being handily outstripped during periods of extreme demand. In a latest bid to fight this problem, smart thermostats are being offered to customers, who will then participate in peak-shaving. The partnership between NRG Energy Inc., Renew Home LLC, and Alphabet Inc. will see about 650,000 of these thermostats distributed to customers.

For customers the incentive would be mostly financial, though the details on the potential cost savings seem scarce. The thermostats would be either a Vivint (an NRG company) or Google Nest branded one, which would be controlled via Google Cloud, allowing for thermostat settings to be changed to reduce the load on the grid. This is expected to save ‘300 MW’ in the first two years, though it’s not clear whether this means ‘continuously’, or intermittent like with a peaker natural gas plant.

Demand curtailment is not a new thing, with it being a big thing among commercial customers in South Korea, as we discussed within the topic of vehicle-to-grid energy storage. Depending on how it is implemented it can make a big difference, but it’ll remain to see how regular consumers take to the idea. It also provides more evidence for reducing grid load being a lot easier than adding grid-level storage, which is becoming an increasingly dire topic as more non-dispatchable solar and wind power is added to the grid.

Making Sense Of Real-Time Operating Systems In 2024

November 13, 2024 by Maya Posch 52 Comments

The best part about real-time OS (RTOS) availability in 2024 is that we developers are positively spoiled for choice, but as a corollary this also makes it a complete pain to determine what the optimal choice for a project is. Beyond simply opting for a safe choice like FreeRTOS for an MCU project and figuring out any implications later during the development process, it can pay off massively to invest some time up-front matching the project requirements with the features offered by these various RTOSes. A few years ago I wrote a primer on the various levels of ‘real-time’ and whether you may even just want to forego an RTOS at all and use a simple Big Loop™ & interrupt-based design.

With such design parameters in mind, we can then look more clearly at the available RTOS options available today, which is the focus of this article. Obviously it won’t be an exhaustive comparison, and especially projects like FreeRTOS have seen themselves customized to various degrees by manufacturers like ST Microelectronics and Espressif, among others. This also brings to the forefront less pleasant considerations, such as expected support levels, as illustrated by e.g. Microsoft’s Azure RTOS (formerly ThreadX) recently getting moved to the Eclipse Foundation as the Eclipse ThreadX open source project. On one hand this could make it a solid open-source licensed RTOS, or it could have been open sourced because Microsoft has moved on to something else and cleared out its cupboard.

Thus without further ado, let’s have a look at RTOSes in 2024 and which ones are worth considering, in my opinion.

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NASA Announces New Trials For In-Space Laser Welding

November 13, 2024 by Maya Posch 20 Comments

In-space manufacturing is a big challenge, even with many of the same manufacturing methods being available as on the ground. These methods include rivets, bolts, but also welding, the latter of which was first attempted fifty years ago by Soviet cosmonauts. In-space welding is the subject of a recently announced NASA collaboration. The main aspects to investigate are the effects of reduced gravity and varying amounts of atmosphere on welds.

The Soviets took the lead in space welding when they first performed the feat during the Soyuz-6 mission in 1969. NASA conducted their own welding experiments aboard Skylab in 1973, and in 1984, the first (and last) welds were made in open space during an EVA on the Salyut-7 mission. This time around, NASA wants to investigate fiber laser-based welding, as laid out in these presentation slides. The first set of tests during parabolic flight maneuvers were performed in August of 2024 already, with further testing in space to follow.

Back in 1996 NASA collaborated with the E.O. Paton Welding Institute in Kyiv, Ukraine, on in-space welding as part of the ISWE project which would have been tested on the Mir space station, but manifesting issues ended up killing this project. Most recently ESA has tested in-space welding using the same electron-beam welding (EBW) approach used by the 1969 Soyuz-6 experiment. Electron beam welding has the advantage of providing great control over the weld in a high-vacuum environment such as found in space.

So why use laser beam welding (LBW) rather than EBW? EBW obviously doesn’t work too well when there is some level of atmosphere, is more limited with materials and has as only major advantage that it uses less power than LBW. As these LBW trials move to space, they may offer new ways to create structure and habitats not only in space, but also on the lunar and Martian surface.

Featured image: comparing laser beam welding with electron beam welding in space. (Source: E. Choi et al., OSU, NASA)

The End Of Ondsel And Reflecting On The Commercial Prospects For FreeCAD

November 12, 2024 by Maya Posch 106 Comments

Within the world of CAD there are the well-known and more niche big commercial players and there are projects like FreeCAD that seek to bring a OSS solution to the CAD world. As with other OSS projects like the GIMP, these OSS takes on commercial software do not always follow established user interactions (UX), which is where Ondsel sought to bridge the gap by giving commercial CAD users a more accessible FreeCAD experience. This effort is now however at an end, with a blog post by Ondsel core team member [Brad Collette] providing the details.

The idea of commercializing OSS is by no means novel, as this is what Red Hat and many others have done for decades now. In our article on FOSS development bounties we touched upon the different funding models for FOSS projects, with the Linux kernel enjoying strong commercial support. The trick is of course to attract such commercial support and associated funding, which is where the development on the UI/UX and feature set of the core FreeCAD code base was key. Unfortunately the business case was not strong enough to attract such commercial partners and Ondsel has been shutdown.

As also discussed on the FreeCAD forum, the Ondsel codebase will likely be at least partially merged into the FreeCAD code, ending for now the prospect of FreeCAD playing in the big leagues with the likes of AutoCAD.

Thanks to [Brian Harrington] for the tip.