#include <SoftwareSerial.h>

// Not all pins on the Mega and R4 boards support change interrupts,
// so only the following can be used for RX:
// Arduino Mega and Mega 2560
// 10, 11, 12, 13, 50, 51, 52, 53, A8 (62), A9 (63), A10 (64), A11 (65), A12 (66), A13 (67), A14 (68), A15 (69)
// Arduino R4 Minima
// 0, 1, 2, 3, 8, 12, 13, A1 (15), A2 (16), A3 (17), A4 (18), A5 (19)
// Arduino R4 WiFi
// 0, 1, 2, 3, 6, 8, 11, 12, A1 (15), A2 (16), A3 (17), A4 (18), A5 (19)


SoftwareSerial mySerial(8, 9);  // RX, TX

void setup() {

  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {  // wait for serial port to connect. Needed for Leonardo only
    ;
  }

  mySerial.begin(4800);
  Serial.println("input command !");

  pinMode(7, OUTPUT);
  digitalWrite(7, HIGH);
  delay(1000);
}

void loop() {

  while (Serial.available()) {
    mySerial.write(Serial.read());
  }

  while (mySerial.available()) {
    Serial.write(mySerial.read());
  }

  // Add a short delay to avoid overwhelming the serial port
  delay(100);
}