Water detector with 4 level stages. Each stage makes the 555 timer to give a supply period for the buzzer. The active buzzer transmits sound with a pause period between 0.5-3 seconds, depending on the level detected.
**Frequency divider 1/3600**
Will be used together with DS1307 RTC module to generate hourly pulse (from SQW/OUT configured to 1 Hz tick).
DS1307 should run on VBAT only, divider module will run on 3.3V.
Falling edge of pulse will be used to wake-up Atmel MCU from deep-sleep...