We could start building the watch straight away since the Particle Core board can be programmed wirelessly and there is no need to have the parts exposed. However, when it comes to any form of prototyping, this is never a good idea, as a lot of things can go wrong on the way, so it's better to break down any project into parts, as we have done throughout this book.

The star of the show will be the screen we use for this project. There is a large variety of different small screens that can be used, and I have chosen the SSD1306, 1.3 inch, 128 x 64 OLED screen from Adafruit. For this project, we will be using the same screen libraries from Adafruit as in the previous chapters, and they have a large selection of screens that work with this library, so you can choose any one you like. The screen I have chosen is black and white, but you can switch it to any of the color screens as well. The design for this project was inspired by a mix of 80s Casio watches and leather straps...