Apple AirTag Spills Its Secrets

The Apple AirTag is a $29 Bluetooth beacon that sticks onto your stuff and helps you locate it when lost. It’s more than just a beeper though, the idea is that it can be silently spotted by any iDevice — almost like a crowd-sourced mesh network — and its owner alerted of its position wherever they are in the world.

There are so many questions about its privacy implications despite Apple’s reassurances, so naturally it has been of great interest to those who research such things. First among those working on it to gain control of its nRF52832 microcontroller is [Stacksmashing], who used a glitching technique whereby the chip’s internal power supply is interrupted with precise timing, to bypass the internally enabled protection of its debug port. The firmware has been dumped, and of course a tag has been repurposed for the far more worthwhile application of Rickrolling Bluetooth snoopers.

The idea of a global network of every iDevice helping reunite owners with their lost possessions is on the face of it a very interesting one, and Apple are at great pains on the AirTag product page to reassure customers about the system’s security. On one hand this work opens up the AirTag as a slightly expensive way to get an nRF microcontroller for other applications, but the real value will come as the firmware is analysed to see how at the tag itself works.

[Stacksmashing] has appeared on these pages many times before, often in the context of Nintendo hardware. Just one piece of work is the guide to opening up a Nintendo Game and Watch.

South Australia Vs. Too Much Home Solar

Once upon a time, the consensus was that renewable energy was too expensive and in too sparse supply to be a viable power source to run our proud, electrified societies on. Since then, prices of solar panels have tanked, becoming more efficient along the way, and homeowners have been installing them on their rooftops in droves.

Where once it was thought we’d never have enough solar energy, in some cities, it’s becoming all too much. In South Australia, where solar output can be huge on a sunny day, electricity authorities are facing problems with grid stability, and are taking measures to limit solar output to the grid.

Isn’t More Usually Better?

The problem faced by South Australian utilities is one of how to properly control an electrical grid with many thousands of distributed power sources. Typically, in conventional modern power grids, voltage and frequency is controlled within set limits by carefully matching the supply from major power plants with the demand from users. Fast-response plants can be brought online to meet shortfalls, and switched off when demand drops, and everything hums along nicely.

Unfortunately, solar power isn’t so easy to throttle, and even less so when it’s coming from thousands of separate households each with their own rooftop install and an inverter to feed back into the grid. This has led to authorities contemplating measures such as charging homeowners to export energy to the grid in peak periods in an effort to slow the huge uptake of home solar systems. Export limits have also been proposed for suburbs with the highest concentration of home solar, as substations in certain residential areas struggle to cope under the huge inflows of energy. Continue reading “South Australia Vs. Too Much Home Solar”

Building An Oxygen Concentrator: It Isn’t Rocket Science

Back at the start of the pandemic, a variety of hacker designs for life-saving machinery may have pushed the boundaries of patient safety. There are good reasons that a ventilator must pass extensive safety  testing and certification before it can be attached to a patient, because were it to in some way fail, the patient would die. A year later, we have many much safer and more realistic ways to use our skills as part of the effort.

Probably one of the most ambitious projects comes from a coalition of Indian hackerspaces who are adapting a proven oxygen concentrator for local manufacture. Among them is Hackaday’s own [Anool Mahidharia], who hosts a Maker’s Asylum video (embedded below) explaining how the oxygen concentrator works and how they can be made safely.

The team have proven their ability in manufacturing over the past year, here showing off the M19 motorised air purifying respirator.
The team have proven their ability in manufacturing over the past year, here showing off the M19 motorised air purifying respirator.

An oxygen concentrator is both surprisingly simple and imbued with a touch of magic. At its center are two columns of zeolite, a highly porous aluminosilicate mineral that performs the task of a molecular sieve. When air is pumped into the column, the zeolite traps nitrogen, leaving the oxygen-enriched remnant to be supplied onwards. There are two such columns to allow each to be on an alternate cycle of enrichment or purging to remove the accumulated nitrogen.

The point of the video is to show that such a device can be constructed from readily available parts and with common tools; as the title says it isn’t rocket science. Concentrators produced by the hackerspace coalition won’t save the world on their own, but as a part of the combined effort they can provide a useful and reliable source of oxygen that will make a significant difference in a country whose oxygen distribution network is under severe strain.

We previously covered the Indian oxygen concentrator effort when they launched the project. Their website can be found on the Maker’s Asylum website, and their crowdfunding campaign can be found on the Indian crowdfunding platform, Ketto. They have already proved their ability to coordinate large-scale manufacturing with their previous PPE and respirator projects, so please consider supporting them if you can. Meanwhile, we can’t help a twinge of space envy, from the fleeting glimpse of Maker’s Asylum in the video.

Continue reading “Building An Oxygen Concentrator: It Isn’t Rocket Science”

Mobile Electronics Workstation Has It All In A Small Package

Home is absolutely everything these days. Plenty of spaces around the abode have had to do double and triple duty as we navigate work, play, and everything in between. Although it’s been a great time to engage in hobbies and even find new ones, where exactly are we supposed put all the stuff that accumulates?

[Fabse89] needed a portable, usable solution for doing electronics work that could be easily packed away. They happened upon a tool case being thrown out, and repurposed it into a great one-stop solution for whenever the urge to play with pixies strikes.

[Fabse89] started by stripping the box out to the bare walls and modeling the inside in Fusion360. Then they built and cut an acrylic insert that holds two power supplies and a soldering station. There are fixed 5 V and 12 V outputs on one power supply, plus a variable supply that maxes out at 48 V.

When it came to tool storage options, [Fabse89] got lucky with a small, seldom-used set of plastic drawers that fits perfectly next to the power station. These hold all the small tools like flush cutters, pliers, and a de-soldering pump. The top section of the case folds back and is the perfect place for component storage boxes. We think this is a tidy solution and especially like that you don’t have to dismantle it to use it — can be used with everything in place and packed up quickly. We also like that the front lid pulls down into a makeshift table, so this really could go anywhere with mains power.

Acrylic not rugged enough for your tastes? Here’s a DIY supply that doubles as a melee weapon.