undermidi

An LFE MIDI Port Server

Dependencies & Setup

This application assumes that the following are on your system:

• git
• GNU make
• A modern install of Erlang (v20+)
• rebar3 (Erlang build tool)
• Golang

This project's rebar.config.script will set the required Go environment variables.

Build & Run

Build the required Go MIDI server and compile the LFE:

$ make clean && make

Start up the LFE REPL:

$ rebar3 lfe repl

Start the app:

lfe> (undermidi:start)

Depending upon the configured log level, you may see a fair amount of output, including the Go MIDI server being started.

API

lfe> (undermidi:ping)
pong

Play the example MIDI code (requires the first MIDI device on your system, index 0, to be connected to a MIDI device, hardware or software, listening on channel 1):

lfe> (undermidi:example)
ok

Macros

The midi macros is provided as a typing convenience for generating MIDI messages:

lfe> (include-lib "undermidi/include/macros.lfe")
|-- loaded include: macros --|
lfe> (midi (midimsg:device 0)
           (midimsg:channel 0))
#(midi
  #(batch
    (#(device 0) 
    #(channel 0))))

The send macro from the same include saves typing when sending many messages to the Go MIDI server. Additionally, macros for MIDI notes are provided via another include:

lfe> (include-lib "undermidi/include/notes.lfe")
|-- loaded include: notes --|
lfe> (set volume 40)
lfe> (progn
       (send (midimsg:device 0)
             (midimsg:channel 0))
       (send (midimsg:note-on (Bb1) volume))
       (timer:sleep 2000)
       (send (midimsg:note-off (Bb1))))