USB dongle Real time clock For raspberry Pi (which does not have one)
Initializes as a USB Serial port when plugged in to any computer and times can be read and set via serial commands
Microchip XC8 Project attached below
PCB Shown is revision 3 as I have been trying to fit it into a small USB dongle enclosure, the one it seems to fit best is the USB-7201-G from Bud Industries.
**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...