I'm currently wearing a F-91W with one of these installed. Here's what I have running:
* Clock
* Sunrise and Sunset times
* Die roller (d2, 4, 6, 8, 10, 12, 20, and 100)
* Stopwatch
* Temperature sensor
* 36-hour temperature log
The die roller was the main one that I was excited about, but the sunrise/sunset seem useful while hiking or backpacking, and the temperature sensor and log are great for camping use. Great job by @josecastillo all around!
It's honestly kind of nice for trivial decision-making. The d2 displays H/t instead of 1 and 2, so it's an actual coin flip. Other than that, I just wanted it for the novelty, pulling it out during D&D was hilarious.
Die are great for decisions you don’t care about. Assign options for eating lunch, say, to numbers, roll the die, if you feel the need to fudge the result now your actual preference is revealed.
There's no FW on it as a programable microcontroller would be far too expensive, it's just glue logic die under a black resin blob, optimized to the absolute bare minimum number of transistors, which you can easily reverse engineer as the die shots are now public[1], but it doesn't help you since you can't reprogram it, it's just to learn how it works.
FWIW, your cheapo basic electric toothbrush without any smart features on it, has a 4-bit Swatch microcontroller[2] from the 90's, with 4K ROM, 320 bytes of RAM (flexes-biceps), for driving the motor, blinking the LED and monitoring the battery level, and this is how you write SW for it[3], and the 90's IDE & toolchain still works on Win 11 today, wild.
This would seem more useful on something like one of the calculator watches or I know I once had a watch with a TV remote built in, not sure offhand if that one was Casio, but that'd seem like something more useful to have in a watch.
I feel like mine was a different model that was not as colorful, but very similar otherwise. It was always fun to control TVs in public and nobody would know who did it or how.
There's a Sensor Watch simulator that demonstrates the features of the various firmware images; this one[1] is running the firmware that shipped with the first boards, and includes a clock, world clock (UTC by default, but customizable by holding the Alarm button), sunrise/sunset, moon phase and temperature. For the sunrise/sunset to work, you'll have to click the "Set Location Register" button, which will prompt for location access.
There are other versions of prebuilt firmware here[2], but my favorite one (even if it's a bit impractical) is the Stargazer firmware[3], whose second watch face can display the locations of the sun, moon and seven planets both in right ascension and declination, as well as altitude and azimuth if you grant location access. We're able to fit a truncated version of the VSOP87 model for planetary motion, right there on your wrist.
At the really simple end, I’m using it to prevent my watch from accidentally switching out of 24h mode, and to disable the hourly beep that can be accidentally turned on.
If I could make one change to my F-91W it would be to use top right number (normally day) to use as an hours counter in stop watch mode. Right now you can only measure 1 hour.
I found this watch because I could not find anything with more than 2 timers. I wanted a watch that has 5+ for cooking. This watch doesn't either, but I'm writing a face in rust to support this case
I also want sunrise/sunset time, random number generator, and hourly beep+30m beep like a ships clock
As long as the watch time doesn't drift drastically, does it really matter? Set it once from your atomic source and it will be fine for seconds accuracy. It's not like you're going to be doing the timing for the LIGO experiment or similar with this watch.
But to directly answer your question, since this board exposes some GPIO and digital buses there's no reason you couldn't built a GPS receiver add on that reads the atomic time from GPS satellite signals and sets the watch time. It would be extra bulk and battery drain of course.
Yep. I tried to go down the wristwatch rabbit hole with a mechanical Seiko but it kept atrocious time. I suppose I could take it to an expert to get regulated but it would still drift.
The casio watches with "waveceptor" / "atomic" radio sync are my favourites now, the feature has become a dealbreaker for me.
WWVB, along with NIST's shortwave time code-and-announcement stations WWV and WWVH, were proposed for defunding and elimination in the 2019 NIST budget.[6] However, the final 2019 NIST budget preserved funding for the three stations.[7]
You are comparing a very purpose-built chip in the original watch to a general purpose microprocessor in this design. The original won't have a single extra transistor than it needs, and it won't be operating one Hz faster than it needs to. Not a surprise to me.
And in reality, the real-life battery life of the Sensor Watch will drop further if you actually attach actual sensors to it or (I'd expect) start running your own code on it.
The Movement framework for developing watch faces tries to steer folks toward low power consumption by default; the watch spends most of its time in standby, and a custom watch face only runs code once per loop (which is once a second by default, although you can request more frequent updates from 1 to 128 Hz). This means most watch faces can actually stay under 10 µA as long as they don't need to update too frequently; up to about 16 Hz, power consumption remains decent.
Anecdotally, my daily driver is coming up on 550 days on the same CR2016 coin cell from February 2022, and I think it's on track to make it to 2024. A far cry from the original's 7+ year battery life, but still pretty good considering all it's capable of!
That is really impressive!!! Are you able to do some kind of power management on any attachable sensors as well besides whatever their standby current is?
This board is an order of magnitude more capable as a general CPU than the original, that's why it takes more power. The SAM L22 processor on it has 32 kilobytes of RAM and 256 kilobytes of code/flash storage vs basically zero memory or programmability on the original. You could easily run micropython, tinygo, johnny five (JavaScript), lua or other high level languages directly on the L22 processor here. It's a fun board for embedded electronics hobbyists. If you've ever played with an Arduino, this is basically one you can wear on your wrist in a classic watch shell.
I don't think this product is for you if you're just expecting a longer battery life watch... and that's ok!
>> Sensor Watch sips single-digit microamperes of power, making this a watch you can wear all year on a single coin cell.
> That's a downgrade vs original board.
> None of the alternative PCBs, clones and such I have seen so far manage to even match the original.
Yeah, but it's still extremely impressive given the upgrade in capability. I'm sure a designer has to make major compromises to optimize for battery life to level of the original.
Though, for something like this, it might have made more sense to target something like the Casio W800H-1AV; which is another cheap classic Casio, but it has a bigger battery, more display capability, and a 4th button.
My first thought as well. I have worn this watch every day since 2009. Last year I changed the battery for the first time. I have always thought that it is the perfect form factor to fit some more fancy stuff in there.
In an update on crowd supply, the creator mentioned he got 425 days of battery life, which I feel like is pretty good considering how powerful the CPU is compared to the original!
I'm not sure that it'd be easy to get that -and- programmability, and past about the 6 month per battery swap mark I'd likely rather have more CPU/RAM/flash than more battery life.
Ok, I just wanted to say that certain models would allow more things to be displayed, like W-800H for example. I actually own F-91W for nostalgia, but it's like a boy watch.
I use my F-91W as a "banger watch" when I'm outside doing a lot of physical work where it might get banged up or covered in dirt. Accurate, so light you barely know you are wearing it, and cheap to replace should I really bang it up. It has been holding up admirably so far. I love it!
Of course, depends on the wrist. It just feels very small to me. I alternate between W-217H, which is a bit larger version, or Casio Duro, which feels like ok size for me, but that's analog.
You're being downloaded because "boy" is diminutive in this context. Like real men can't wear small watches. Which is, of course, unnecessary cock sizing.
Development and reverse engineering probably takes ~500 hours. They probably won't sell more than 1,000 (I'm making these numbers up). Cost for a small run of boards with component placement, with shipping is probably $20-30. They're probably not making much.
Edit: On the crowdsupply page, they mention "As of today, we’ve shipped nearly 1,500 of them. That’s 1,500 boards manufactured by PCBWay, assembled by Cyber City Circuits, and tested, packed and shipped by me personally, plus 1,500 temperature sensor boards hand-assembled by yours truly." Hand-assembly of SMT components is very laborious and not very fun, so that will add at least 10 minutes per board, which adds another 250+ hours of work.
* Clock
* Sunrise and Sunset times
* Die roller (d2, 4, 6, 8, 10, 12, 20, and 100)
* Stopwatch
* Temperature sensor
* 36-hour temperature log
The die roller was the main one that I was excited about, but the sunrise/sunset seem useful while hiking or backpacking, and the temperature sensor and log are great for camping use. Great job by @josecastillo all around!