Hollow Clock 4 - Pico

A remix of the Hollow Clock 4 by shiura which uses the Raspberry PI Pico instead of the original Arduino. The design has a modified base for the larger Pico CPU board and the addition of time adjustment buttons (slow/fast forward, slow/fast backward). A short button press results in slow incremental time change, a longer button press results in fast continuous time change.

A support has been added for the rear cover providing additional mechanical rigidity to the hour and minute rotors. Hour tics have been added to the rear cover to improve visibility of the time.

Mechanical assembly is essentially the same as the original Hollow Clock 4 with the exception of the additional rear rotor support which mounts to the cover (cap) with M3 x 6 screws and is fastened to the rear rotor cover with a suitable adhesive (CA, epoxy, etc).

The Pico CPU and stepper controller PCB are soldered together (GP6 thru GP9, pins 9 thru 12 respectively). The stepper control PCB header pins IN4 thru