New RTC Has No NVSRAM

[frishkorn]

PCF8523 contains no NVSRAM like the DS1307, this will cause issues with reloading the last project, as well as what time format user selected. Will need to find a work around.

[frishkorn]

Can use the EEPROM emulation on the flash. However the draw back to this is more write wear compared to a traditional EEPROM. Due to this the follow actions should be taken.

1. Remove the heartbeat code.
2. Only when user presses the SELECT button to start the timer, should the last used project be written.
3. Pressing the RIGHT button to change format time will need to write to flash.
4. Changing time for shall update the counter.
5. A counter should be created to keep track of how many time the flash has been written to.
6. That counter should be displayed over Serial at startup.

[frishkorn]

Removed all code dealing with heartbeat.

[frishkorn]

Good library to use to utilize emulated EEPROM address space on ATSAMD21. https://github.com/cmaglie/FlashStorage

[frishkorn]

New code for Flash EEPROM has been added. Old nvram code has been removed. Testing now.

[frishkorn]

Operations are now working as expected and this issue can now be closed.