My relatives has a school, of little children, and sometimes the personal in charge of ringing the bell are very busy with some issues which comes with School Managing job; so, the schedules some times are not accomplished. So, I decided to build many years ago, a Timer capable to ring a bell, alarm, whatever attached to its relay at determinate times of day. All this first prototype, only using test pcb stripped boards, not in a finished PCB BOARD with professional quality. THIS YEAR, is the year.
Design based on PIC 16F877A, with ring the Bell in schedules programmed automatically, no need to human intervention.
simulation running in Proteus 8
Mode 0: Showing current Time
Mode 1: Set Events Time (events from 1 to 20)
Bellow, a video showing how its activated the Relay to ring the Bell, at events time programmed: