I love this! As a daily user of the F-91W I do on occasion wish it had a few more features, but it mostly satisfies my needs. I love the form factor and the weight. I just wish it at least had a countdown timer.

You wanted to build a screen? Is there no screen with that size?

Maybe not lcd, but eink instead

This type of LCD are custom made because of the particular segment layout. See the /screen/ section in the linked page.

But you could just have an eink display with higher resolution and build segments out of pixels. Maybe it doesn't look as good but would be more flexible and would have a chance of actually shipping a complete watch

Loved the idea. Fascinating blend of design and functionality. You should kickstarter this.

agreed, the only way i got enough capital to fund a batch of injection molded cases was by kickstarting

my secret was not trying to turn a single kickstarter into an entire business ;)

more of a 'drop' mentality really helps

also: https://news.ycombinator.com/item?id=37054130

Beautiful write up and project!

I remember reading about another Casio retrofit:

https://github.com/carrotIndustries/pluto

That version did not have wireless comms - they touch on that in the faq.

Yeah, the sensor watch [0] also mentioned in another comment re-uses the original screen.

[0] https://www.sensorwatch.net/

Shit, this is just what I want. A casio with vibration notification. If you ever get back in, I'll definitely buy a couple just to support you.

As a daily user of this watch that's exactly the kind of smartwatch I would love to buy.

oh my goodness. That is beautiful - an amazing design for a first hardware project and I would love to see it come to fruition. No experience from my end that would assist, but all the best.

What's so failed about it

I've never managed to build the screen. A smartwatch without a screen is not great :)