Sensor Watch board replacement for the Casio F-91W
Watches and me
While I won't qualify myself as a watch tinkerer (I do not fix watches), I still like owning and using different watches - mostly digital and/or smart watches:
- I have written extensively on the PineTime on that blog (see the PineTime tag), even though I use it a bit less these days
- I use extensively my Suunto Vertical sport watch when running and exercising (which reminds me I still need to write an article on it, since it replaced my beloved Suunto 9 Peak Pro)
I touted about my testing of other watches, including the Sensor Watch board replacement for the Casio F-91W, so here is finally an article about it.
Philosophy of Sensor Watch
Unlike smart watches, Sensor Watch is not looking at providing "smart" features, notifications or heart rate/sleep measurements: it just can't since it's leveraging the very humble Casio F-91W watch, which has been produced for 30 years and costs around 20€.
Instead, the idea is to replace the F-91W board with a more powerful, and programmable one.
You can easily download prebuilt firmwares from the Sensor Watch website, or build your own firmware by picking the watchfaces you want.
The board's swap is super easy to perform, and there's even a video showing you how to do it - you'll just need a soldering iron if you want the buzzer to work when pressing buttons or to have the alarm wake you up.
Firmwares
Sensor Watch comes with a default list of watchfaces, but you can build your own firmware with the watchfaces you want - which is what I did - I have an upcoming article about how to do it on FreeBSD.
Picas!
Board
Here's how the board looks like, before assembling it into the F-91W body:
Clock watchface
Very close to the default Casio one.
World Clock
Displays several time zones, the 2 letters for "day of the week" indicating which timezone you're looking at.
In my case I have India (I8) and Pacific (P8), as well as Australia (not pictured):
Tomato Productivity Timer
If like me you're using the Pomodoro Technique, then this watchface is super useful:
Sunrise / Sunset
As the name suggests, this watchface displays the next event happening, so sunrise in the evening, and sunset during the day.
In below's pica, sunset on that day was at 18:36 (or 6:36 pm).
Staying longer than a week
I initially wanted to wear every watch for a week, and write an article about it.
I started with the Casio+Sensor Watch, as I had received the board for a while
and hadn't swapped it yet.
I did the swap on January 12,
2024 and 6 weeks later
(as I type those words), I'm still wearing it a my wrist!
Tags: Geek