#define ESPSerial Serial1


void setup() {
  // wait for hardware serial to appear
  while (!Serial);

  // make this baud rate for the MCU
  Serial.begin(115200);

  // 9600 baud rate for the EPS
  ESPSerial.begin(9600);
}


void loop() {
  if (Serial.available()) {
    char c = Serial.read();
    ESPSerial.write(c);
  }
  if (ESPSSerial.available()) {
    char c = ESPSerial.read();
    Serial.write(c);
  }
}