RTC Shield

Hi,

after some research I started to design an Arduino UNO/MEGA compatible real time clock shield.

The commonly used RTCs like DS1307 are bad regarding quiescent current and accuracy.
Additionally some DS3231 breakout boards are equipped with a charging circuit which lets the battery explode. I found only one example with a supercap as backup power.

So, what are your demands for a Real Time Clock Shield for Arduino UNO/MEGA ?

For example:

Minimum time keeping current [nA]
Accuracy at room temperature [ppm]
Backup power duration [hours]

Breakout possibility with mounting

Check status backup power supply
I2C bus
Square Wave Output

compatibel with Arduino timelib.h
...

Please have also a look at the attached schematics.

RTC Shield 0.0.3.pdf (148 KB)