Posted in clock hacks Tagged clock, ds1307, pic, real time clock, volt meter. Auto-locking Pet Door Ensures That Your Outdoor Kitty Obeys Its Curfew. April 4, 2012 by Mike Nathan 26 Comments ...

An Atmega328 is used for the main microcontroller which communicates via I2C both to a DS1307 real time clock (RTC) and a TEA5767 FM module.

The Real Time Clock (RTC) SGC22300 uses the leading oscillator solution SGC21510. ... Clock is a full hardware (FPGA) only implementation of a synchronization core allowing to read and write a I2C ...