Chapter 1: Music Shield

Arduino Leonardo with the SparkFun Music Instrument Shield (DEV-10587). The output requires amplification, so I have it plugged into an amp.

1.1 Code

/*
 Based off code from:
 Spark Fun Electronics 2011
 Nathan Seidle
 */
#include <SoftwareSerial.h>
SoftwareSerial mySerial(2, 3); //Soft TX on 3, we don't use RX in this code

byte note = 0; //The MIDI note value to be played
byte resetMIDI = 4; //Tied to VS1053 Reset line
byte ledPin = 13; //MIDI traffic inidicator
int instrument = 0;

void setup() {
  Serial.begin(57600);

  //Setup soft serial for MIDI control
  mySerial.begin(31250);

  //Reset the VS1053
  pinMode(resetMIDI, OUTPUT);
  digitalWrite(resetMIDI, LOW);
  delay(100);
  digitalWrite(resetMIDI, HIGH);
  delay(100);
}

void loop() {

  talkMIDI(0xB0, 0x07, 120); //0xB0 is channel message, set channel volume to near max (127)

  Serial.println("Basic Instruments");
  talkMIDI(0xB0, 0, 0x00); //Default bank GM1

  //Change to different instrument
  for(instrument = 0 ; instrument < 127 ; instrument++) {

    Serial.print(" Instrument: ");
    Serial.println(instrument, DEC);

    talkMIDI(0xC0, instrument, 0); //Set instrument number. 0xC0 is a 1 data byte command

    play_note(0, 48, 60, 150);
    play_note(0, 48, 60, 150);
    play_note(0, 55, 60, 150);
    play_note(0, 55, 60, 150);
    play_note(0, 57, 60, 150);
    play_note(0, 57, 60, 150);
    play_note(0, 55, 60, 300);

    delay(300); //Delay between instruments
  }
}

void play_note(byte channel, byte note, byte attack_velocity, byte length) {
      //Note on channel 1 (0x90), some note value (note), middle velocity (0x45):
      noteOn(0, note, 60);
      delay(length);
      //Turn off the note with a given off/release velocity
      noteOff(0, note, 60);
      delay(50);  
}
//Send a MIDI note-on message.  Like pressing a piano key
//channel ranges from 0-15
void noteOn(byte channel, byte note, byte attack_velocity) {
  talkMIDI( (0x90 | channel), note, attack_velocity);
}

//Send a MIDI note-off message.  Like releasing a piano key
void noteOff(byte channel, byte note, byte release_velocity) {
  talkMIDI( (0x80 | channel), note, release_velocity);
}

//Plays a MIDI note. Doesn't check to see that cmd is greater than 127, or that data values are less than 127
void talkMIDI(byte cmd, byte data1, byte data2) {
  digitalWrite(ledPin, HIGH);
  mySerial.write(cmd);
  mySerial.write(data1);

  //Some commands only have one data byte. All cmds less than 0xBn have 2 data bytes 
  //(sort of: http://253.ccarh.org/handout/midiprotocol/)
  if( (cmd & 0xF0) <= 0xB0)
    mySerial.write(data2);

  digitalWrite(ledPin, LOW);
}