Payment card chip

My old payment card (chip-and-pin credit/debit) expired some time ago and as usual bank delivered new one and told me to cut the old one to pieces. Around here chip-and-pin has been typical for long time now so naturally this old card had the chip too. Out of curiosity I decided to see if I could take it out and see ... well, anything at all.

After some careful cutting I managed to get the contacts and chip off the plastic, here seen under microscope (on metal standoff)

The  other side. Somewhat blurry, rounded things around the center are openings to contacts on other side and yellow-ish rectangle in center the chip itself. You can also see five wires connecting the chip to the contacts. All that is under some kind of protective glue or filling. I actually expected to see only a typical black blob but I don't mid this at all. Already I could tell that this was pretty much everything I could hope to see with my limited set of tools; aside tiny openings on chip for the wires, it seemed to be entirely covered with some kind of mask (that's the yellow-ish part, picture doesn't really have enough resolution to see it properly).

After some careful bending the blob broke and exposed the chip inside, but it was (as expected) also ruined in the process. No matter though, I don't have suitable equipment or chemicals to see any deeper anyway. I'm willing to bet though that there are many others who have done deeper analysis of these chips (on both white-hat and black-hat sides of the fence).

So a quick glance on the chip. Nothing unexpected, really, and digging deeper would some better equipment (chemical and/or machinery) than I have available.

Re-purposing old Bluetooth hands-free

Before finding the handy Bluetooth receiver I considered repurposing old handsfree unit I had used ages ago. The exact model is Jabra BT205, maybe from ten years ago or so. I never managed to get comfortable with this type of hands-free unit so eventually I just got a car radio with built-in Bluetooth hands-free. Much much better.

Now that I thought about getting rid of wires for hearing protector I actually considered if this could be used. It naturally doesn't have the newer audio codec in it, just the original voice-only codec of original Bluetooth specification, but quality still might be tolerable for audiobook use.

Before tearing this down I tried charging it. Completely dead. Guess ten years of inactivity wasn't good for the lithium battery pack. I already had some doubts on whether this could be adapted to work with 2 AA batteries (that the hearing protector uses) but decided to go in anyway.

After some careful attempts the device came apart nicely. Electronics and battery are inside another plastic module, and connected to battery, charging port, microphone and headphone with wires.

Opening inner plastic was easy enough and I could access the PCB. Nothing surprising there, main Bluetooth chip (in middle) and assorted components elsewhere. Here earpiece wires go to left (best guess that chips near it are amplifier), microphone to up (I might have pulled wires enough to expose copper when opening it), battery down and charge port wires top right.

On the right side of the battery wires, at the bend you can see exposed (gold-colored) copper at the edges of the PCB with curious loop connecting them. This would be the 2.4GHz antenna. The copper on edge extends to both sides and bottom of PCB too; I'm somewhat curious on the process how they have managed to make this work, as cutting the shaped PCB off the larger board often destroys traces too near the cutting edges. Must be some kind of post-cut process I've never heard of.

Main chip is CSR BC215, which from basic search seems to be (unsurprisingly) made-for-the-job chip. As usual for many old chips, finding proper datasheet for this seems to be a bit difficult (I don't specifically need that data so no real effort wasn't spent on trying to find it). No proper datecode on any chips either, so I'll just settle on that earlier ten-year guess.

Now, on the bad things. While the board still works and connects to my phone easily enough (and music quality was as bad as I expected), as it is designed to work with lithium battery (i.e. about 3.6v nominal), there is no way to get it to work with just 2 AA batteries of hearing protector; when lowering the voltage it turned itself off at about 2.8 volts, way too high for 2 AAs.

So this is about as far as I got. Unless I come up with something else, there is no point going any further with this for now.

But before that I have to mention the charger too. This being fairly old device it comes with a special dock onto which HF is dropped in to be charged. On other side there is fairly standard (of that time) round power plug, albeit with less standard 6v voltage. In this picture I had already opened it so PCB is visible. The three contacts are for charging; voltage in middle, two ground pins on the sides.
Remember, this was long before (almost) everyone settled into USB charging (and back then USB connectors were huge for device like this, no microUSB yet!) so this isn't too weird.

Inside was pretty much as I expected. Well, almost, I expected to find just wires between power plug and charger pins but surprisingly there's actually a PCB in there!

And in trash it goes. The charger I mean, earpiece PCB itself might prove handy someday so that'll I keep. At least for a while.

Biking around Oulu: some pictures

This post has absolutely nothing to do with electronics, but anyway. Oulu region has considered itself to have great biking routes and I have to agree - just a short biking distance away from downtown you can bike (or hike) on forest paths, likely without meeting anyone else. Short distance of course is somewhat relative, but within, say, 10 km there is already plenty to choose from, although paths near populated areas naturally have more people on them. So instead of maybe one person on path that is farther away you'll meet five.

I prefer not to bike same routes every time, instead trying to find new routes I haven't biked before. When getting further away from downtown this gets a bit more difficult at some point as many forest paths are often dead ends, instead of getting from a larger road to another. While I try to avoid worst paths, sometimes my route selections aren't always... umm, optimal.

This is a track left by some forest machine, like this for example, and water is about 20cm deep, with soft ground below. Not exactly prime biking ground (and I actually ended up pushing the bike while standing on firmer ground on sides). Before this, there were a maybe a kilometre or two of sand, then route changed to essentially swamp for about a kilometre before getting better again. It paid out however;

Sanginjoki region has some great biking and hiking routes. This is from Kalimenlampi (lake Kalime) where I stopped shortly before proceeding to drive back home (via much easier path than one above). There are of course multiple better routes there than the one I picked this time, also many accessible with a normal car. I just like to pick and try new routes over ones I've driven before whenever possible.

This is from few years ago from Kalime's campfire location (small "hut" that can be seen on background on above picture) on evening around this time of year when nights start to get dark again after sunny "nightless nights" of north.

From another trip, this is from old, large sawmill area near the sea near Pateniemi area. It used to be quite badly polluted, but there's been a cleanup going and at the moment there are apparently plans to build homes there.

Panning above slightly left. Unfortunately (from my point of view) building this area will mean the loss of nice bike-able/walk-able outdoors area but apparently money talks.

Next time, back to actual electronics.

Traveling with equipment, always exciting

Although the timing of this post was somewhat pushed up by the recent news of the Texan kid and his experiences with local authorities concerning his clock, this topic has been in my mind for fairly long time now.

When I was in my teens I saw an opinion piece in a local newspaper that essentially said that since some people get to travel for work (to other countries or even continents), that should be treated as taxable benefit.

Even then I knew that to be really ignorant position. Since then I've developed opinion on travel general, not just work travel: The only bad part with travelling is the actual travel part.

I haven't seen any hints of transporters (of Star Trek fame) becoming viable form of travel any time soon, so I have to resort to lesser methods when travelling is needed for work. And occasionally I need to travel by air. Now, I don't think airport security in Europe has delved as deeply into field of total theatrical insanity as on the other side of the pond, but still it's a chore. Once they even wanted to take my damn sunglasses out from my backbag and their soft carrycase to be X-rayed again, only separately. I really can't see any point in that, but I digress here ...

As luggage sometimes is lost, I try to pack as much of the absolutely necessary equipment in my hand luggage so if it is lost, there's no one other to blame than myself. Lost luggage can really ruin your day if the equipment urgently needed was there - and you're in, say, London while your luggege was last seen in Abu Dhabi. And you have only day or two scheduled for the job.

Fortunately stuff I need doesn't include anything banned from planes, like knives, chemicals and such. Then again, often I do carry around both packaged electronic devices and various makeshift looking things. For example something like this;

This is nothing but optical isolator with some passives around it for input filtering and current limiting. Completely harmless. Yet whenever you see a bomb denonator in films or television series they always look something like this.

And I fear that some day, some security person will want to take a closer look at my equipment and cause some serious -- shall we say -- inconvenience...

BT audio for headphones

Some time ago I expressed my unhappiness about fragility of headphone cables. Since then I have managed to break another pair of (cheap) in-ear headphones, once again from twisting the connector experienced when phone was in my pockets while biking around (I'll post some pictures about these bike trips soon, they'll have absolutely nothing to do with electronics but I'll allow myself some liberties on topics here).

I was already thinking about tearing down my old but still functional Jabra headphone set (which however is not very usable in even somewhat loud surroundings and it has stupid flashing leds that make it look completely idiotic when in public) and adapting it to my existing headphones, as well as tearing down and adapting even older headset meant only for voice calls (I think that it doesn't even support even newer audio codec, only the older voice codec - which would be no problem as I only listen to audiobooks these days).

However, after some digging around I found a bluetooth receiver built for the job. I think the brand is this (Finnish) web shop's own brand so this very same device is very likely available under other names elsewhere.

The device itself is about same size as my little finger so it isn't too large, although it might seem huge in picture. Although there are still wires involved, receiver can remain clipped safely near the headphones  relatively unmoving so stress on wires and plugs is massively reduced (I've had it clipped on shirt collar or my cap's visor, depending on situation - latter is naturally better suited for forest work or such activities where fashion can be completely ignored.)  Even with small in-ear headphones I use while biking this was vast improvement - if I didn't often use my map browser while out I could even toss the phone in my backbag!

The audio stutters occasionally a bit so it isn't great device, especially for music, but for audiobooks it's fine. I've never had similar stuttering with either my cars' Bluetooth radios (one factory default, one aftermarket) so problem must be in this device.

The only major drawback I've so far encountered is battery life - I think product spec promised around 7 hours, which is slightly less than I'd like. Based on my experience so far I estimate that promise to be fairly close to actual. However, it it only warns you about low battery during final 15 minutes or so, so it's very easy to forget to charge it when it doesn't have much juice left. This is even more annoying since my phone gets fairly consistent 5 days of use between charges so option of charging both at same time isn't very useful (it isn't just my usage - I had to send phone to be repaired so I used Android phone I had for development/testing for a week and it got barely two days - at best - between charges with exactly same usage pattern! - but I digressing here)

Even better, this is also way cheaper than hearing protectors with bluetooth built-in, especially since it can be used with both my hearing protectors and in-ear headphones. I consider this thing absolutely worth its price - which was around 30 euros - low enough that I wouldn't even bother with straight-from-china -offerings as they tend to be gamble at best. If I'd spend 8 hours a day, every (work) day with hearing protects on, I'd still spend extra 100-200 towards Bluetooth-enabled protectors however.

(and no, shop isn't paying me a cent for this advertisement-ish review, I am just fairly happy to have found a nice solution to minor annoyance)

Rant: Windows' calculator

Windows 10, in many aspects (excluding primarily privacy) is pretty nice system. For example I was extremely and pleasantly surprised that it actually properly detected and installed USB serial (COM) driver even without having it in database, without needing that simple .inf file to tell it that "USB serial" device actually is USB serial, like with previous versions of windows (.inf being plain text that essentially gives name to device, so why exactly it needed to be signed, requiring damn reboots to install?)

One seemingly minor thing that has been going the wrong way lately is the simple calculator.

In windows XP (I'm not sure of Vista) there was essentially "simple" and "advanced" view, latter that included most of the functions I need; primarily of course decimal to hex (or binary, or other way) conversions. In advanced mode you could do decimal math (0.235 * 3 = ??) or change values from decimal to hex at will with no mode changes. Simple, easy, useful.

In Windows 7 that was replaced with newer calculator program. This also had separate modes for calculation: basic, programmer and scientific. I use programmer mode most of the time, but here is the bad thing: you couldn't do decimal math (like 0.235 * 3 above) at all in that mode, only integers. To deal with decimal values you'd have to switch to another mode. Unfortunately I need both decimal and hex math essentially all the time, so this added completely unnecessary mode switch. Not good.

Now, with Windows 8 (or 8.1, I never used 8 myself) they upated calculator again, and the same version seems to be used in Windows 10. You guess where this is goind already? Yup, changes weren't good.

Previous versions of calc accepted both comma and dot keys as decimal separator (I most often used comma, being at a locale where that is decimal separator). New version doesn't, I have to use dot key as decimal separator. Actually, scratch that - as a huge insult to history of localisation of windows, calculator isn't following system locale at all - I'm using Finnish locale, but calculator uses US locale exclusively (dot decimal separator, comma to separate thousands and so on).
What the actual fuck, Microsoft?

It also takes (relatively) ages to start. Previous versions were instantly there but this one takes between one to five seconds to start. Completely unacceptable for simple program like that. And I don't even bother mentioning stupidity of "shift" key to change operation used in desktop app (I know, it's supposed to be "universal". I read that "universally useless".) This calculator is nothing but complete disaster. I certainly hope that this stupidity doesn't continue and extend to other aspects of the OS, but I am afraing that we all know the answer to that already...