Need to catch up? Have a look at the changelog! 🚀
ex-portmidi is a wrapper for the PortMidi C library, that provides some nice abstractions to (write to|listen on) MIDI devices.
Add portmidi to your list of dependencies in mix.exs, and ensure
that portmidi is started before your application:
def deps do
[{:portmidi, "~> 5.0"}]
end
def application do
[applications: [:portmidi]]
end
If needed, the input buffer size can be set, in your config.exs:
config :portmidi, buffer_size: 1024
By default, this value is 256.
To send MIDI events to a MIDI device:
iex(1)> {:ok, output} = PortMidi.open(:output, "Launchpad Mini")
{:ok, #PID<0.172.0>}
iex(2)> PortMidi.write(output, {176, 0, 127})
:ok
iex(3)> PortMidi.write(output, {{176, 0, 127}, 123}) # with timestamp
:ok
iex(4)> PortMidi.write(output, [
iex(5)> {{176, 0, 127}, 123},
iex(6)> {{178, 0, 127}, 128}
iex(7)> ]) # as a sequence of events (more efficient)
:ok
iex(8)> PortMidi.close(:output, output)
:ok
To listen for MIDI events from a MIDI device:
iex(1)> {:ok, input} = PortMidi.open(:input, "Launchpad Mini")
{:ok, #PID<0.103.0>}
ex(2)> PortMidi.listen(input, self)
:ok
iex(3)> receive do
...(3)> {^input, event} -> IO.inspect(event)
...(3)> end
{144, 112, 127}
iex(4)> PortMidi.close(:input, input)
:ok
To list all connected devices:
ex(1)> PortMidi.devices
%{input: [%PortMidi.Device{input: 1, interf: "CoreMIDI", name: "Launchpad Mini",
opened: 0, output: 0}],
output: [%PortMidi.Device{input: 0, interf: "CoreMIDI",
name: "Launchpad Mini", opened: 0, output: 1}]}
For more details, check out the Hexdocs.