void setup() {
  // Start the serial communication at 19200 baud
  Serial.begin(19200);
  Serial.println("Echo app started at 19200 baud. Type something:");
}

void loop() {
  // Check if data is available on the serial port
  if (Serial.available() > 0) {
    // Read a byte of data from the serial port
    char incomingByte = Serial.read();

    // Echo the received byte back to the serial port
    Serial.print("Echo: ");
    Serial.println(incomingByte);
  }
}