You put an Arduino-compatible microcontroller on a custom PCB, obviously. A QFN package ATTiny is like 4mm square.
It’ll all be SMT parts if you want it to be watch-sized, so you’ll have to let JLCPCB or whoever assemble the board for you instead of soldering it yourself, but it’s surprisingly accessible to random hobbyists these days.
Get a smaller Arduino, there are a ton of options with low power. You can 3D print a mockup (check your local library if you don’t have access to one) before designing the full product
If you go completely custom and get it right the first time (unlikely), you can probably get a prototype for $1k or so with a custom PCB and high quality 3D printed case (molds are expensive).
It would require a lot of learning if this is your first time, but 3D printer + tiny Dev board can get you very far for very little money (<$100 if you have access to a 3D printer).
The best part is you can make your own!
With what? I don’t own a watch factory.
Arduino
How are you gonna fit an Arduino in a watch?
You put an Arduino-compatible microcontroller on a custom PCB, obviously. A QFN package ATTiny is like 4mm square.
It’ll all be SMT parts if you want it to be watch-sized, so you’ll have to let JLCPCB or whoever assemble the board for you instead of soldering it yourself, but it’s surprisingly accessible to random hobbyists these days.
Yeah I don’t understand any of these words.
Ok, maybe you specifically shouldn’t make your own, but somebody else who knows this things could.
What part of you just DHRT the CNGIR to the WKFI do you not understand?!?
Don’t forget the screen and the battery too.
Get a smaller Arduino, there are a ton of options with low power. You can 3D print a mockup (check your local library if you don’t have access to one) before designing the full product
If you go completely custom and get it right the first time (unlikely), you can probably get a prototype for $1k or so with a custom PCB and high quality 3D printed case (molds are expensive).
It would require a lot of learning if this is your first time, but 3D printer + tiny Dev board can get you very far for very little money (<$100 if you have access to a 3D printer).
Fine, Raspberry Pi.