Adding Smart Watch Features To Vintage Casio

[Matteo] has been a fan of the Casio F-91W wristwatch virtually since its release in 1989. And not without good reason, either. The watch boasts reliable timekeeping and extremely long battery life thanks to a modern quartz crystal and has just about every feature needed in a watch such as an alarm and a timer. And, since it’s been in use since the 80s, it’s also a device built to last. The only thing that’s really missing from it, at least as far as [Matteo] was concerned, was a contactless payment ability.

Contactless systems use near-field communication (NFC) to remotely power a small chip via a radio antenna when in close proximity. All that’s really required for a system like this is to figure out a way to get a chip and an antenna and to place them inside a new device. [Matteo] scavenges the chip from a payment card, but then builds a new antenna by hand in order to ensure that it fits into the smaller watch face. Using a NanoVNA as an antenna analyzer he is able to recreate the performance of the original antenna setup in the smaller form factor and verify everything works before sealing it all up in a 3D-printed enclosure that sandwiches the watch.

There are a few reasons why using a contactless payment system with a watch like this, instead of relying on a smartwatch, might be preferential. For one, [Matteo] hopes to explore the idea that one of the physical buttons on the watch could be used to physically disable the device to reduce pickpocketing risk if needed. It’s also good to not have to buy the latest high-dollar tech gadget just for conveniences like this too, but we’ve seen in the past that it’s not too hard just to get these systems out of their cards in the first place.

16 thoughts on “Adding Smart Watch Features To Vintage Casio

  1. The hack is pretty neat, but in my opinion (and probably that of the source) that watch is more of a classic than modern at this point. The 30 year old tech is still fine as far as accuracy, but alarms and timers are far from the limit of “dumb” watch capabilities. The retro look with the modern capability is a definite statement, though! Hopefully it handles moisture okay.

    Regarding non-smartwatch capabilities, I have opinions :D. I think anyone can benefit from solar and wireless time reception, including daylight savings time, along with a true calendar that doesn’t skip leap days and such. That makes the watch so “dumb” you almost never need to touch its controls afterwards apart from if you need to change time zones. Oh, and unlike with a smartwatch, being waterproof to a certain depth is a given. The wireless time can be regular radio or, nowadays, maybe GPS – although the ones that go that far often end up adding bluetooth and might be categorized at least semi-smart. My watch has more than just about anything that still has an analog face. It’s one of the newer casios that actually also has a compass, barometer, and thermometer, and while the thermometer isn’t much use in air unless you take off the watch and wait a bit, it still works underwater too so I guess you could make something of that. The first two are more useful to me. The compass seems a bit more accurate than my phones have been, even if I will use GPS when I have it for actually navigating, so I can locate radio towers for WISP aiming, or just generally help maintain my bearings with it / figure out what a building in the distance is. Plus you can orient north/south with the face at 90 degrees to the usual orientation, and with a bit of effort figure out vertical angles since the magnetic field goes into the ground at some angle. That probably translates to your latitude, actually, and you can probably get longitude just from the sun’s position and the exact time/date, again with effort as it’s not a built in feature. The barometer can give some indication of weather at a static elevation, or vice versa elevation if the weather hasn’t changed too much. Features can all be calibrated and adjusted, e.g. if you don’t want it to turn the light on when you tip your wrist you can turn that off. I wish it also had a humidity meter; that’d help with the weather prediction and it would be a neat thing to know the dew point and such on the fly and as a function of time the way it already graphs the pressure.

    1. I have a similar Casio Protrek – as I obviously have similar requiremenats to a wristwatch. solar, 200m water resistancwe,… The only difference: I deliberately did not want to waste space for an analog face. A pure digital watch-face for me, please.

      1. I can’t argue; the analog face isn’t as info-dense as a lcd or epaper display. It’s possible to make the non-lcd surface into almost 100% solar panel, though instead they generally conceal the panel for appearance’s sake – still good for power though. And as for appearance or style, unfortunately in some circumstances any analog watch makes a better impression than e.g. a g-shock mudmaster with a canvas velcro strap or something. It’s a shame, but I like the analog face so hey. Mine’s the PRW-50YT-1 which I was surprised to find for a cheap price secondhand before it was released in the U.S. Those are a little smaller than the older models.

  2. The title is a quite click-baity. There is ONE “smart watch” feature added to the vintage Casio, it’s literally JUST a payment SIM and antenna added on top with a 3D printed case. Sure it’s a hack but “smart watch features” could have been replaced by “contactless payment”.

  3. “Described as a “genius” bomb manufacturer by a former US counter-terrorism expert, Al-Qaeda’s Ramzi Yousef was known for using the F-91W. ”

    Yousef used an op-amp connected to the F91W alarm powered by a 9-v battery, we read and saw.

    Schematic disappeared from Internet?

  4. “We hackers, extremely lazy people, always look for the shortest path with the least effort to achieve the maximum results.”
    Never before have I felt so validated as a hacker. Lol

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