Browse Source

implement serial MIDI interface

master
Peter Cai 1 year ago
parent
commit
a7bc05506d
  1. 3
      .gitmodules
  2. 1
      ArduinoMIDI
  3. 1
      Makefile
  4. 65
      main.cpp

3
.gitmodules vendored

@ -0,0 +1,3 @@
[submodule "ArduinoMIDI"]
path = ArduinoMIDI
url = https://github.com/FortySevenEffects/arduino_midi_library

1
ArduinoMIDI

@ -0,0 +1 @@
Subproject commit d501f4bb3dfff548a7cef4d85371bec0b438bdd7

1
Makefile

@ -23,6 +23,7 @@ VPATH := $(foreach path, ${VPATH}, ${path} $(shell find ${path} -type d))
# This is to prevent the command above from including directories like .git into
# the VPATH list
VPATH += ${PWD} \
${PWD}/ArduinoMIDI/src \
# Build parameters
BUILD_DIR := out

65
main.cpp

@ -1,8 +1,11 @@
#include <Arduino.h>
#include <MIDI.h>
#include "motor_control.h"
#define NUM_MOTORS 4
using namespace midi;
MotorControl motors[NUM_MOTORS] = {
MotorControl(5, 2),
MotorControl(6, 3),
@ -10,6 +13,18 @@ MotorControl motors[NUM_MOTORS] = {
MotorControl(13, 12)
};
// MIDI setup
struct MySerialMIDISettings {
// ttymidi wants a baud rate of 115200
static const long BaudRate = 115200;
};
typedef SerialMIDI<HardwareSerial, MySerialMIDISettings> MySerialMIDI;
MySerialMIDI serialMIDI(Serial);
MidiInterface<MySerialMIDI> MIDI(serialMIDI);
void handle_tick(unsigned long cur_micros) {
// Randomize the order we process motor ticks every time
// This helps reduce the minor frequency discrepancies between each motor
@ -19,6 +34,20 @@ void handle_tick(unsigned long cur_micros) {
}
}
#define ASSERT_CHANNEL() \
if (channel <= 0) return; \
if (channel - 1 > NUM_MOTORS) return;
void midi_note_on(uint8_t channel, uint8_t note, uint8_t velocity) {
ASSERT_CHANNEL();
motors[channel - 1].TickAtPitch(note);
}
void midi_note_off(uint8_t channel, uint8_t note, uint8_t velocity) {
ASSERT_CHANNEL();
motors[channel - 1].TickOff();
}
int main() {
// Arduino library initialization
// Needed for some functions to work (like micros)
@ -33,39 +62,17 @@ int main() {
motors[i].Init();
}
// Test: play Twinkle Twinkle Little Star
unsigned long note_time = 500ul * 1000ul; // 500 ms
unsigned int seq_motor[4][15] = {
{ 60, 60, 67, 67, 69, 69, 67, 0, 65, 65, 64, 64, 62, 62, 60 },
{ 57, 57, 64, 64, 65, 65, 64, 0, 62, 62, 60, 60, 59, 59, 57},
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
{ 48, 48, 53, 53, 48, 48, 0, 0, 53, 53, 48, 48, 55, 55, 48},
};
unsigned long last_note_ts = 0;
int cur_note = -1;
// Start serial MIDI interface
MIDI.begin(MIDI_CHANNEL_OMNI);
// Set up MIDI callbacks
MIDI.setHandleNoteOn(midi_note_on);
MIDI.setHandleNoteOff(midi_note_off);
while (true) {
unsigned long cur_micros = micros();
handle_tick(cur_micros);
if (cur_micros - last_note_ts >= note_time) {
last_note_ts = cur_micros;
cur_note += 1;
for (int i = 0; i < 4; i++) {
if (seq_motor[i][cur_note] != 0) {
motors[i].TickAtPitch(seq_motor[i][cur_note]);
} else {
motors[i].TickOff();
}
// Prevent out of bounds access
if (cur_note >= 15) {
motors[i].TickOff();
while (true) {}
}
}
}
MIDI.read();
}
return 0;

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