Headworx

USB Type-C (usually referred to as USB-C) chargers support a fairly sophisticated protocol for selecting charging voltage and current. What is important, when nothing is connected to a USB-C port, no power is provided. The device that wants to be charged must tell the charger what it wants. Otherwise no charging takes place. This is designed so for may reasons, but the simplest explanation is: a connected device may not want to be charged at all: imagine using a USB-C cable to connect one charger to another charger. If there was any voltage present by default, the result could be catastrophic. The simplest way to tell the charger to offer the default 5V (as in USB-A legacy chargers) is to use the so-called Dead Battery mode. This is described in Section 4.8.5 of the Type-C specification. The device that wants to be charged (known as the Sink) must apply 5.1kΩ resistors to both CC1 and CC2 lines (pins). The term Dead Battery (from the Type-C specification perspective) describes a device...

I have a truly love-and-hate relationship with my Garmin watch. I love it for the looks. And for keeping record of my daily trail runs. And for holding backup topographic maps of (almost) the entire planet. And for being the flight computer on long distance flights. Actually the last part is also a contributor to the hate part. As it keeps the location track in flight through combined satellite readings, it also updates its time to the GPS time. And a time zone with it - meaning it always shows accurate time for the current location. Which is useless when you are just a passenger. You wake up in the night, look at the watch - it shows time, but at a glance you just don't have an idea in which time zone you are in. Yes, there is always 1pm somewhere on Earth. But generally when flying, the best way is to have either the departure time zone or the arrival time zone, not something in between. A phone use to be then a much more convenient time source - just showing the departure time z...

So much for iPhone privacy. I had thought that paying in a physical store with contactless Apple Pay was more or less protecting my privacy. It turns out this is not the case. I mean of course paying by credit card you give your static credit card number to the merchant. But that should be it, right? Just the number. Not your email, home address, phone number and God knows what else. So I was quite stunned in Queenstown, New Zealand, after landing I went to a sports shop to buy some freeze dried food and a gas canister. When paying I rarely pay attention to the details other than the transaction amount but I thought there was a glimpse of my phone number and my email on the terminal for a short while. This was confirmed later this day when I received a bunch of emails from the store - welcome, coupons etc. Had I provided them with this data voluntarily? Nope. I even went through my email history and there was no trace of any earlier communication from that store chain. So they must hav...

Phones are now absolutely essential items in our (connected) lives. It becomes impossible to read an email (2-factor authentication), authorize a financial transaction (often as simple as a credit card purchase) or board a plane. The trend keeps going further, as we have been now transferring identity documents to phones' "wallets" (including many official government-made applications). Then there are social aspects like electronic messaging, photo sharing. And navigation (car or trail / backcountry). At the same time it has become increasingly more difficult to make a simple backup device, as many of the above mentioned services are tied to digital security / identity chips that by design are impossible to backup and require full reinstallation of the digital services. I covered this in my recent phone migration blogs here and here ). Long story short - changing a phone (voluntarily as an upgrade or being forced to as a result of a device loss or damage) requires plenty...

There are several things that give me goosebumps. Or make me think how little we comprehend / understand about the weird world we live in. Physics - the way we have it now - is completely bent. Totally far from being intuitive and understandable. Take the John Wheeler's double-slit experiment . A source of light and a screen with two thin, vertical slits. You shine the light through the slits, the light acts like a wave., interferes with itself, resulting in a ripple-like pattern on the wall. Turn the light down to only a single photon. The photon acts like a particle: hits the wall in one specific spot. But after enough photons arrive, the same interference pattern emerges. The single photon interferes with itself. Now add a detector to the slits, to figure out which slit the photon actually passed through. When you do this, you never get an interference pattern on the far wall. The OBSERVATION (not any interaction with) of the photons affected their behavior. Then there...

There are myriads of legal nonsense situations we encounter every day. Somehow the most often they are related to general information technology (IT). Definitely #1 are the EU cookie banners. David Heinemeier Hansson (DHH) - the creator of Ruby on Rails - has been perhaps more vocal about the EU Cookie Mandate (specifically cookie banners) than almost anybody else. He views them as a prime example of well-intentioned but fundamentally "stupid" and failed legislation. He points out that companies have spent billions of dollars on compliance, legal fees, and implementation, yet there has been no material improvement to user privacy. Most users simply click "Accept" to get the banner out of the way, effectively granting the very tracking permissions the law intended to curb. And the bureaucracy refuses to admit the solution didn't work. And #2 are variety of Terms of Use (ToU) that must be accepted to do something. For example, when you first pull the battery tab o...

I'm writing this post in December, 2025, in preparation for couple of weeks' holidays In January / February. I understand packrafting now may sound a bit extreme, but hey, it is peak summer now in New Zealand. And NZ is where it all started - I found this article (see the snapshot) in an old magazine that was left in one of the New Zealand's mountain huts. That was in 2024 - almost two years ago. Since then we have completed a white water packrafting camp to get familiar with packrafts and river rafting / kayaking in general. That was in Slovenia, and is a great idea for an active summer adventure in Europe. Then we found a great supplier of packrafting gear in Poland - I mentioned packraft.pl in my Spring'2025 post on the subject. Now we are back to where it all began. Not as ambitious as Mitchell Radford, but his documentary is definitely a good one to understand what this activity is all about.  We're also trying to pack much lighter than he did. 39 kg / 85 lbs...