Circuits.I2C.bus_names

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

Specs

bus_names() :: [binary()]

Return a list of available I2C bus names. If nothing is returned, it's possible that the kernel driver for that I2C bus is not enabled or the kernel's device tree is not configured. On Raspbian, run raspi-config and look in the advanced options.

iex> Circuits.I2C.bus_names()
["i2c-1"]