If an external connection is provided via the I2C connector, an external connection can be made to the D8 (SDA) and D7 (SCL) pins with the I2C interface with the same pin configuration; However, do not make any external connections to these pins.
When removing your card, which is placed on a breadboard or similar unit, you must carefully hold its edges, as shown in the image, to prevent damage to the USB port.
Maximum Voltage in Analog Reading
A0, A1, A2, A3, A4, A5, A6, A7, DA0 and DA1 pins with 13-bit resolution can be used as input pins for analog signals. These pins give the maximum value of 8191 at a voltage of approximately 2.60 V.