Advent Calendar Arduino. Each day at a predetermined time 5:00pm the clock will tell the microcontroller it's time to drop a bottle. Simple advent calendar on arduino idea of the calendar is:

This one dispenses holiday cheer, the 50ml type. This page includes links to each day’s guide for our 12 projects of codemas maker advent calendar, which include component details, wiring guides & diagrams, example micropython code and many examples on how to combine.