An on-and-off switch is a feature that I didn't have in the design of the initial prototype, but became obvious is needed during testing. This allows users to turn off the watch when not worn to conserve battery life.

Initially my plan was to have the ATTiny85 go to low power sleep when the power down button is pressed and then awaken using an interrupt when pressed again. But I later realized that I don't need something as complicated as this. It's the correct approach if I have an external crystal for timing. For my current design, a simple slide switch in between the battery and the circuit is simpler.

As you can see there is a slot that allowed me to secure the slider in place. I also had to rotate and move motor which I am not sure is okay as it may have affected how strong the motor is felt.

The next and possibly last step for this version of the prototype is testing how long it would run under normal use. I'll also begin plans for the next prototype iteration which I am excited for.