Clicked on this thinking it was about a calculator, so impressed that it was about swapping out the guts of an casio watch and building and uploading the firmware.
What's the process of adding sensors to the custom motherboard? Based on your watchface config it looks like you added accelerometer. I wonder what other sensors are easy to add. I'd love to have an hrm in mine
IMO the Casio Oceanus S100 is a better watch in that category - solar powered, radio-controlled, waterproof, no apps or connectivity, but more dressy. However it's JDM only so you have to order it off eBay (or buy it on a trip to Japan I suppose).
Admittedly my watch only gets 1/50 the battery life and doesn't pick up WWV. On the other hand, being able to redesign its face in Emacs and Illustrator and update it OTA makes up for a lot. So does not having to wear a molded polymer bracelet - those things are awful!
What's wrong with molded polymer bracelets? I assume you're referring to the wristband?
I've really only worn one watch and it has a molded polymer wristband, and it doesn't bother me, but maybe I'm missing out on something nicer.
Reminds me of the Texas Instrument Chronos, which was a watch that existed solely to promote the MSP430. I think it was released around 2013. Looks like it's no longer in production, but you can find them used around $40.
This is a really simple "project" because someone else did all the work! I just had to install the thing and make some tiny code modifications for my taste.
The key to doing things when you're very busy is to do them slowly and not drive yourself crazy with a deadline. When I did the ThinkPad 701c restoration it took me a year!
> Since I bought the optional accelerometer add on it's necessary to put in place a little piece of caption tape
This should be _Kapton Tape_ https://croylek.com/pages/kapton-tape?srsltid=AfmBOoqVfkbfaW...
Argh. Motherducking autocorrect!
Clicked on this thinking it was about a calculator, so impressed that it was about swapping out the guts of an casio watch and building and uploading the firmware.
I have been reluctantly holding off hoping they will come out with a dot matrix or epaper screen. Neither will probably ever happen but I can dream.
There is this one: https://gitlab.com/_Pegor/kepler_fw
I absolutely loved my Pebble. It was so amazing in its own niche.
You do know that Pebble is back from the dead?
https://repebble.com
What's the process of adding sensors to the custom motherboard? Based on your watchface config it looks like you added accelerometer. I wonder what other sensors are easy to add. I'd love to have an hrm in mine
There are details on the sensor part here: https://www.sensorwatch.net/docs/sensorboards/ and reference designs here: https://github.com/joeycastillo/Sensor-Watch/tree/main/PCB/S...
> git clone --recurse-submodules [...]
Small improvement but it should get the clone and the submodules at the same time.
TSA: "Sir, are you wearing the terrorist watch?"
You: "no no, it's a modified terrorist watch, it now has more features!"
https://www.spiegel.de/international/world/al-qaida-s-watch-...
https://www.watchesofespionage.com/blogs/woe-dispatch/casio-...
Typically I wear this watch instead: https://blog.jgc.org/2025/06/the-discreet-charm-of-infrastru...
brb gotta buy a casio lineage watch now
IMO the Casio Oceanus S100 is a better watch in that category - solar powered, radio-controlled, waterproof, no apps or connectivity, but more dressy. However it's JDM only so you have to order it off eBay (or buy it on a trip to Japan I suppose).
Admittedly my watch only gets 1/50 the battery life and doesn't pick up WWV. On the other hand, being able to redesign its face in Emacs and Illustrator and update it OTA makes up for a lot. So does not having to wear a molded polymer bracelet - those things are awful!
What's wrong with molded polymer bracelets? I assume you're referring to the wristband? I've really only worn one watch and it has a molded polymer wristband, and it doesn't bother me, but maybe I'm missing out on something nicer.
Reminds me of the Texas Instrument Chronos, which was a watch that existed solely to promote the MSP430. I think it was released around 2013. Looks like it's no longer in production, but you can find them used around $40.
This, is how to enjoy your retirement. Hope we see lots of other fun projects like this from you John, a very enjoyable read. :)
This is a really simple "project" because someone else did all the work! I just had to install the thing and make some tiny code modifications for my taste.
Very cool! What's the expected battery run time?
See: https://www.crowdsupply.com/oddly-specific-objects/sensor-wa... Answer: 1 to 2 years. My previous watch from the original blog post is still running on the original battery.
Thank you, John.
Coincidentally, your web site https://jgc.org/ is truly a lovely example of https://news.ycombinator.com/item?id=44613625 which was just discussed today as well.
Love your behind the screens stuff!
Thanks! Glad you enjoy https://behind-the-screens.tv. Those videos were an enormous amount of work because of all the original research behind them. I do have one more I'd like to do about this film: https://www.rottentomatoes.com/m/defense_play_1987 One day perhaps!
Oh I don't doubt it! I was thinking how does such a busy man have time for this... but we always have time for passions and side projects :)
The airwolf one was funny, since it was a childhood favorite, and what a funny little typo they had there.
When watching the video I was thinking to myself, could this series have influenced my future interests in ways I didn't even know? Fun.
The key to doing things when you're very busy is to do them slowly and not drive yourself crazy with a deadline. When I did the ThinkPad 701c restoration it took me a year!
Old Thinkpads were truly glorious machines. Top notch engineering and materials.
is any Linux version? I'm not using brew
Windows, macOS and Linux instructions here: https://www.sensorwatch.net/docs/movement/building/
Brew run on Linux just as well as on MacOS.
It’s actually the default package manager for uBlue distros.
I’ve used it as my only package manager on Linux for a few years and I love it.
Respect.
This is a brill project
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