The Arduino Nano itself is the most basic and oldest ... and their A4 and A5 pins both double as SDA and SCL pins for I2C/TWI communication. However, the Nano offers a slight advantage as it ...

The Nano also conveniently works with the Arduino IDE out of the box ... and SCK), and one I2C/TWI (pins A4 and A5 as SDA and SCL). The Pico, however, doubles these numbers.