Arduino LCD Keypad hotkey example which moves windows

keep_alive_and_window_mover.ino

#include <Keyboard.h>
#include <Mouse.h>
#include <LiquidCrystal.h>


/*
   Arduino 2x16 LCD - Detect Buttons
   modified on 18 Feb 2019
   by Saeed Hosseini @ Electropeak
https://electropeak.com/learn/
*/
//LCD pin to Arduino
const int pin_RS = 8;
const int pin_EN = 9;
const int pin_d4 = 4;
const int pin_d5 = 5;
const int pin_d6 = 6;
const int pin_d7 = 7;
const int pin_BL = 10;
LiquidCrystal lcd( pin_RS,  pin_EN,  pin_d4,  pin_d5,  pin_d6,  pin_d7);

// All keys are connected to the A0 pin so they will read with analogRead(0)
// https://create.arduino.cc/projecthub/electropeak/using-1602-lcd-keypad-shield-w-arduino-w-examples-e02d95

// Keyboard Scan Codes from usb_hid_keys.h
// https://gist.github.com/MightyPork/6da26e382a7ad91b5496ee55fdc73db2
#define KEY_LEFT_GUI  0x83 // 131
#define KEY_UP_ARROW  0xDA // 218
#define KEY_DOWN_ARROW  0xD9 // 217
#define KEY_LEFT_ARROW  0xD8 // 216
#define KEY_RIGHT_ARROW 0xD7 // 215

// realistically, you could cascade x < 60, x < 200, x < 400, x < 600
// but this allows specifically checking for a direction without
// assuming that directions that had lower analog values were checked
#define IS_RIGHT(x) ((x)>=0 && (x)<60)
#define IS_UP(x) ((x)>=60 && (x)<200)
#define IS_DOWN(x) ((x)>=200 && (x)<400)
#define IS_LEFT(x) ((x)>=400 && (x)<600)
#define IS_SELECT(x) ((x)>=600 && (x)<800)


void blinkIfYoureRebooted() {
  // 200, 400, 600, 800, 1000ms blinks
  for(int i=1; i<=5; i++) {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(200 * i);
    digitalWrite(LED_BUILTIN, LOW);
    delay(200 * i);
  }
}

void setup() {
  // this runs once  
  pinMode(LED_BUILTIN, OUTPUT);
  blinkIfYoureRebooted();
  Mouse.begin();
}

char translateToOutputKey(int analogRead) {
  if(IS_RIGHT(analogRead)) { return KEY_RIGHT_ARROW; }
  if(IS_UP(analogRead)) { return KEY_UP_ARROW; }
  if(IS_DOWN(analogRead)) { return KEY_DOWN_ARROW; }
  if(IS_LEFT(analogRead)) { return KEY_LEFT_ARROW; }
  return 0;
}

void loop() {
  char key;
  
  key=translateToOutputKey(analogRead(0));

  if(key) {
    Keyboard.begin();
    Keyboard.press(KEY_LEFT_GUI);
    Keyboard.press(key);
    Keyboard.releaseAll();
    delay(200); // debounce
  } else {
    // 10090 is a completely arbitrary number but
    // it seems to move a barely perceptible amount
    // a few times per second at most.
    if(random(0,10090)==0) {
      Mouse.move(random(0,5)-2, random(0,5)-2,0);
    }
  }
}