Datasheet

In the top right, SDA (rightmost) and SCL (to the left of SDA) are used to talk to the RTC chip.

SCL - I2C clock pin, connect to your microcontrollers I2C clock line. This pin has a 10K pullup resistor to 3.3V

SDA - I2C data pin, connect to your microcontrollers I2C data line. This pin has a 10K pullup resistor to 3.3V

These pins are in the same location on every Feather

There's also a breakout for INT which is the output pin from the RTC. It can be used as an interrupt output or it could

also be used to generate a square wave.

Note that this pin is open drain - you must enable the internal pullup on whatever digital pin it is connected to!

SD & SPI Pins