View Source Circuits.SPI.Backend behaviour (circuits_spi v2.0.4)
Backends provide the connection to the real or virtual SPI controller
Summary
Callbacks
Return SPI bus names on this system
Return information about this backend
Open a SPI bus device
Callbacks
Return SPI bus names on this system
No supported options
@callback info() :: map()
Return information about this backend
@callback open(bus_name :: String.t(), [Circuits.SPI.spi_option()]) :: {:ok, Circuits.SPI.Bus.t()} | {:error, term()}
Open a SPI bus device
On success, open/2 returns a reference that may be passed to
with transfer/2. The device will be closed automatically when
the reference goes out of scope.
SPI is not a standardized interface so appropriate options will different from device-to-device. The defaults use here work on many devices.
Parameters:
bus_nameis the name of the bus (e.g., "spidev0.0"). Seebus_names/0optsis a keyword list to configure the bus