elixir_bme680 v0.1.2 Bme680 View Source
elixir_bme680
provides a high level abstraction to interface with the
BME680 environmental sensor on Linux platforms.
Link to this section Summary
Functions
Returns a specification to start this module under a supervisor
Invoked when the server is started. start_link/3
or start/3
will
block until it returns
Perform a measurement on the BME680 sensor and synchronously return it
Perform a measurement on the BME680 sensor and asynchronously send the result
as a message to the pid in send_to
Starts and links the Bme680
GenServer
Link to this section Functions
Returns a specification to start this module under a supervisor.
See Supervisor
.
Invoked when the server is started. start_link/3
or start/3
will
block until it returns.
args
is the argument term (second argument) passed to start_link/3
.
Returning {:ok, state}
will cause start_link/3
to return
{:ok, pid}
and the process to enter its loop.
Returning {:ok, state, timeout}
is similar to {:ok, state}
except handle_info(:timeout, state)
will be called after timeout
milliseconds if no messages are received within the timeout.
Returning {:ok, state, :hibernate}
is similar to {:ok, state}
except the process is hibernated before entering the loop. See
c:handle_call/3
for more information on hibernation.
Returning {:ok, state, {:continue, continue}}
is similar to
{:ok, state}
except that immediately after entering the loop
the c:handle_continue/2
callback will be invoked with the value
continue
as first argument.
Returning :ignore
will cause start_link/3
to return :ignore
and
the process will exit normally without entering the loop or calling
c:terminate/2
. If used when part of a supervision tree the parent
supervisor will not fail to start nor immediately try to restart the
GenServer
. The remainder of the supervision tree will be started
and so the GenServer
should not be required by other processes.
It can be started later with Supervisor.restart_child/2
as the child
specification is saved in the parent supervisor. The main use cases for
this are:
- The
GenServer
is disabled by configuration but might be enabled later. - An error occurred and it will be handled by a different mechanism than the
Supervisor
. Likely this approach involves callingSupervisor.restart_child/2
after a delay to attempt a restart.
Returning {:stop, reason}
will cause start_link/3
to return
{:error, reason}
and the process to exit with reason reason
without
entering the loop or calling c:terminate/2
.
Callback implementation for GenServer.init/1
.
measure(GenServer.server()) :: %Bme680.Measurement{ gas_resistance: integer() | nil, humidity: float(), pressure: float(), temperature: float() }
Perform a measurement on the BME680 sensor and synchronously return it
Measurements are structs like:
%Bme680.Measurement{
temperature: 21.74,
pressure: 1090.52,
humidity: 45.32,
gas_resistance: 10235
}
measure_async(GenServer.server(), pid()) :: :ok
Perform a measurement on the BME680 sensor and asynchronously send the result
as a message to the pid in send_to
start_link([i2c_device_number: integer(), i2c_address: 118 | 119], [term()]) :: GenServer.on_start()
Starts and links the Bme680
GenServer.
Gracefully stops the Bme680
GenServer.