Code for atmega32u4-based OBS scene switcher

obs_switcher.ino

/**********************************************************************
/* Copyright 2017 Jonathan Beri
/* 
/* Licensed under the Apache License, Version 2.0 (the "License");
/* you may not use this file except in compliance with the License.
/* You may obtain a copy of the License at
/* 
/*     http://www.apache.org/licenses/LICENSE-2.0
/* 
/* Unless required by applicable law or agreed to in writing, software
/* distributed under the License is distributed on an "AS IS" BASIS,
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/* See the License for the specific language governing permissions and
/* limitations under the License.

#include "Keyboard.h"

// 32u4 has 5 interrupts [3,2,0,1,7]
const byte interruptPin0 = 3;
const byte interruptPin1 = 2;
const byte interruptPin2 = 0;
const byte interruptPin3 = 1;
const byte interruptPin4 = 7;

volatile byte command = 0;

void setup() {
  // Pullup to set HIGH since ISR is called on LOW
  pinMode(interruptPin0, INPUT_PULLUP);
  pinMode(interruptPin1, INPUT_PULLUP);
  pinMode(interruptPin2, INPUT_PULLUP);
  pinMode(interruptPin3, INPUT_PULLUP);
  pinMode(interruptPin4, INPUT_PULLUP);
  
  attachInterrupt(digitalPinToInterrupt(interruptPin0), ISR_setCommand1, LOW);
  attachInterrupt(digitalPinToInterrupt(interruptPin1), ISR_setCommand2, LOW);
  attachInterrupt(digitalPinToInterrupt(interruptPin2), ISR_setCommand3, LOW);
  attachInterrupt(digitalPinToInterrupt(interruptPin3), ISR_setCommand4, LOW);
  attachInterrupt(digitalPinToInterrupt(interruptPin4), ISR_setCommand5, LOW);
  
  Keyboard.begin();
}

void loop() {
  // Change keyboards commands here. See also https://www.arduino.cc/en/Reference/KeyboardModifiers
  switch(command) {
    case 1:// ⌘+1. 
      Keyboard.press(KEY_LEFT_GUI);
      Keyboard.press('1');
      Keyboard.releaseAll();
      command = 0;
      break;
    case 2:
      Keyboard.press(KEY_LEFT_GUI);
      Keyboard.press('2');
      Keyboard.releaseAll();
      command = 0;
      break;
    case 3:
      Keyboard.press(KEY_LEFT_GUI);
      Keyboard.press('3');
      Keyboard.releaseAll();
      command = 0;
      break;
    case 4:
      Keyboard.press(KEY_LEFT_GUI);
      Keyboard.press('4');
      Keyboard.releaseAll();
      command = 0;
      break;
    case 5:
      Keyboard.press(KEY_LEFT_GUI);
      Keyboard.press('5');
      Keyboard.releaseAll();
      command = 0;
      break;
    default:
      command = 0;
      break;      
  } 
}

void ISR_setCommand1() {
  command = 1;
}

void ISR_setCommand2() {
  command = 2;
}

void ISR_setCommand3() {
  command = 3;
}

void ISR_setCommand4() {
  command = 4;
}

void ISR_setCommand5() {
  command = 5;
}