Midi filtertering of stop start messages

Projects Programming
30

That's fantastic! That's much clearer to me now and easier to add any extras I may need down the line! I've added in some extra code as I wanted to use GM midi to access some percussion sounds from a synth chip to create a metronome triggered by the sequencer or master clock. Below is my updated code for anyone who may need it. Thanks immensely blh64 and Deva_Rishi for your time and help!

#define drumchan           9

// general midi drum notes
#define note_snaredrum    37 // rimshot!


// MIDI clock as per Little Scale
byte midi_start = 0xfa;
byte midi_stop = 0xfc;
byte midi_clock = 0xf8;
byte midi_continue = 0xfb;

static uint8_t clk = 0;


// Variables
int tempoled = 13;
int play_flag = 0;
byte data;


// Setup
void setup() {
  Serial.begin(31250);
  pinMode(tempoled, OUTPUT);
}


// Program
void loop() {

  if (Serial.available() > 0) {
    data = Serial.read();

    if (data == midi_start) { // if midi in start
      Serial.write(midi_start); // send midi out start
      play_flag = 1;
      clk = 0;
    }

    if (data == midi_continue) { // if midi in continue
      Serial.write(midi_continue); // send midi out continue

      play_flag = 1;
    }

    if (data == midi_stop) { // if midi in stop
      Serial.write(midi_stop); // send midi out stop
      digitalWrite(tempoled, LOW);
      play_flag = 0;
    }



    if ((data == midi_clock) && (play_flag == 1)) {
      if (clk == 0) {
        digitalWrite(tempoled, HIGH);
        noteOn(drumchan,  note_snaredrum, 100);
      }
      if (clk == 7) {
        digitalWrite(tempoled, LOW);  // this should light it up for 25% of the time
        noteOff(drumchan,  note_snaredrum, 0);
      }
      clk = (clk + 1) % 24;
      Serial.write(midi_clock); // send midi clock to out... Provides tempo!
    }
  }
}
// Send a MIDI note-on message.  Like pressing a piano key
// channel ranges from 0-15
void noteOn(byte channel, byte note, byte velocity) {
  midiMsg( (0x90 | channel), note, velocity);
}

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

// Send a general MIDI message
void midiMsg(byte cmd, byte data1, byte data2) {
  Serial.write(cmd);
  Serial.write(data1);
  Serial.write(data2);
}

:slightly_smiling_face: