Circuits.I2C.open

You're seeing just the function open, go back to Circuits.I2C module for more information.

Specs

open(binary() | charlist()) :: {:ok, bus()} | {:error, term()}

Open an I2C bus

I2C bus names depend on the platform. Names are of the form "i2c-n" where the "n" is the bus number. The correct bus number can be found in the documentation for the device or on a schematic. Another option is to call Circuits.I2C.bus_names/0 to list them for you.

I2c buses may be opened more than once. There is no need to share an I2C bus reference between modules.

On success, this returns a reference to the I2C bus. Use the reference in subsequent calls to read and write I2C devices