MIDI Merge for ATmega4809 (Curiosity Nano)

midi-merge.c

/*
 * MIDI Merge for ATmega4809
 * Copyright (c) 2020 Benjamin Alman
 * MIT License
 */
 
#include <MIDI.h>

MIDI_CREATE_INSTANCE(HardwareSerial, Serial,  midi_1);
MIDI_CREATE_INSTANCE(HardwareSerial, Serial1, midi_2);
MIDI_CREATE_INSTANCE(HardwareSerial, Serial3, midi_3);

// https://camo.githubusercontent.com/60339c7a6884cc766b6b80761017eeca1edab842/68747470733a2f2f692e696d6775722e636f6d2f626d64664346532e6a7067
#define LED_TX  39
#define LED_RX1 38
#define LED_RX2 37
#define LED_RX3 36

void setup() {
  pinMode(LED_TX, OUTPUT);
  pinMode(LED_RX1, OUTPUT);
  pinMode(LED_RX2, OUTPUT);
  pinMode(LED_RX3, OUTPUT);

  midi_1.begin(MIDI_CHANNEL_OMNI);
  midi_2.begin(MIDI_CHANNEL_OMNI);
  midi_3.begin(MIDI_CHANNEL_OMNI);
  // Serial3.begin(57600);
}

const int LED_DURATION = 500;
const int MIDI_INPUT_COUNT = 3;

midi::MidiInterface<midi::SerialMIDI<HardwareSerial>> midi_tx = midi_2;
midi::MidiInterface<midi::SerialMIDI<HardwareSerial>> midi_rx[MIDI_INPUT_COUNT] = {midi_1, midi_2, midi_3};
int led_rx_pin[MIDI_INPUT_COUNT] = {LED_RX1, LED_RX2, LED_RX3};
int led_rx_count[MIDI_INPUT_COUNT] = {0, 0, 0};

bool show_led(int type) {
  return type != 254; // active sensing
}

void loop() {
  int read_count = 0;
  int off_count = 0;

  for (int i = 0; i < MIDI_INPUT_COUNT; i++) {
    if (midi_rx[i].read()) {
      int type = midi_rx[i].getType();
      int data1 = midi_rx[i].getData1();
      int data2 = midi_rx[i].getData2();
      int channel = midi_rx[i].getChannel();
      midi_tx.send(type, data1, data2, channel);
      // Serial3.printf("[MIDI %i] ch=%2i type=%3i data1=%3i data2=%3i\n", i + 1, channel, type, data1, data2);
      if (show_led(type)) {
        digitalWrite(led_rx_pin[i], HIGH);
        read_count++;
        led_rx_count[i] = 0;
      }
    }

    if (++led_rx_count[i] >= LED_DURATION) {
      led_rx_count[i] = LED_DURATION;
      digitalWrite(led_rx_pin[i], LOW);
      off_count++;
    }
  }

  if (off_count == MIDI_INPUT_COUNT) {
    digitalWrite(LED_TX, LOW);
  } else if (read_count != 0) {
    digitalWrite(LED_TX, HIGH);
  }
}