This repo is a fork from https://github.com/lucidstack/ex-portmidi by @thbar, with continuous integration enabled (against MacOS), targetting Elixir 1.12 and OTP 24. It contains fixes for all the warnings I could find, and updated test dependencies.
It may or may not diverge from the original fork in the future, and has not been published to Hex at this point, so you'll have to install from GitHub.
On MacOS, brew install portmidi is assumed (as keg-only), and the makefile will look for include files and dynamic library via brew --prefix.
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.