MIDI to Arduino Source Code Generator - Documentation

beep

A simple tone generator (see tone), but works with the attiny84. The beep() function isn't built into Arduino, so it will be appended to the generated sketch. You can optionally add a second pin number for a simple volume boost.

Notes Notes will be recreated audibly. So if your MIDI file has a middle C, a square wave tone will be generated at 262hz.
Duration beep() is a blocking call! You cannot overlap events for the duration of a beep note in any track.
Velocity Velocities are pretty much ignored - if you create a note with any non-zero velocity, a tone will be generated.

digital

Controls a pin's HIGH/LOW state using digitalWrite().

Notes Different notes don't matter - any note on the track will control the pin state. Notes should not overlap.
Duration The pin will bet set HIGH for the duration of the note. At the end of the note, the pin will be set to LOW.
Velocity Any non-zero velocity will set the pin HIGH.

servo

Connect a servo's control/data wire to this pin to control the angle of the servo's arm.

Notes Different notes don't matter - any note on the track will control the servo rotation the same. Notes should not overlap.
Duration At the end of a note's duration, the servo will be reset to 90°.
Velocity

Velocity is used to control the servo's rotation.

MIDI velocities range from 0-127, while servo angles range from 0-180, so the values are mapped. If you turn a note's velocity all the way up (127), the servo will be rotated all the way up (180°); if the MIDI note only goes half-way (63), the servo will only be rotated half-way (90°); etc.

tone

Plug one end of a speaker into this pin and the other end into GND to generate simple tones (see beep for attiny84 support).

Notes Notes will be recreated audibly. So if your MIDI file has a middle C, a square wave tone will be generated at hz.
Duration A delay() will be added for the duration of the note (or until the next event (whichever comes first)). At the end of the note's duration, a noTone() call is added to stop the tone, as well as an extra, short delay() to prevent consecutive notes from interfering with each other.
Velocity Velocities are pretty much ignored - if you create a note with any non-zero velocity, a tone will be generated.

pwm

Generates PWM signals (analog-approximations)

Notes Different notes don't matter - any note on the track will control the PWM state of the pin. Notes should not overlap.
Duration The pin's PWM value will be set for the duration of the note. At the end of the note, the pin will be set to zero.
Velocity

Velocity is used to control the PWM state.

MIDI velocities range from 0-127, while Arduino PWM values range from 0-255, so the values are mapped. If you turn a note's velocity all the way up (127), the servo will be rotated all the way up (255); if the MIDI note only goes half-way (63), the servo will only be rotated half-way (128); etc.