// Can other Serial/UARTS ports redirect to the Serial Monitor ?
// Answer: Yes.
//
// Reference: https://reference.arduino.cc/reference/en/language/functions/communication/serial/
// 
// Mega 2560 Rev3:
//   Serial  = 0(RX), 1(TX)
//   Serial1 = 19(RX1), 18(TX1)
//   Serial2 = 17(RX2), 16(TX2)
//   Serial3 = 15(RX3), 14(TX3)
//
// file "diagram.json" for Serial1:
//    "connections": 
//    [
//      [ "mega:19", "$serialMonitor:TX", "" ],
//      [ "mega:18", "$serialMonitor:RX", "" ]
//    ]
//
// This project: https://wokwi.com/projects/424176908696674305
// See also the test with Uno: https://wokwi.com/projects/424176849827515393 

#define _SERIAL Serial3

unsigned long count;

void setup() 
{
  _SERIAL.begin(115200);
  _SERIAL.println("Hello Mega");
}

void loop() 
{
  _SERIAL.print(count++);
  _SERIAL.print(" ");
  if(_SERIAL.available() > 0)
  {
    _SERIAL.println();
    while(_SERIAL.available() > 0)
    {
      int inChar = _SERIAL.read();
      if(isprint(inChar))
        _SERIAL.write(inChar);
    }
    _SERIAL.println();
  }
  delay(1000);
}