I2C
To set I2C communication parameters, use the I2C options. The pins in the I2C0(default) option are the Arduino® header pins mentioned in https://os.mbed.com/platforms/ for the selected Nucleo board.
Bus speed (in Hz)
Use the I2C option to set the bus speed parameter. The bus speed determines the rate of data communication between the peripherals that are connected together by the I2C bus.
Settings
Default:100000
Serial clock (SCL) pin
An SCL pin for the SCL clock signal that the I2C Master generates.
Serial data (SDA) pin
An SDA pin for SDA data signal.