#include <SoftwareSerial.h>

SoftwareSerial ss(6, 5);

void setup() {
  Serial.begin(9600);
  ss.begin(9600);
}

void loop() {
  if (Serial.available()) {      // If anything comes in Serial (USB),
    ss.write(Serial.read());   // read it and send it out Serial1 (pins 0 & 1)
  }

  if (ss.available()) {     // If anything comes in Serial1 (pins 0 & 1)
    Serial.write(ss.read());   // read it and send it out Serial (USB)
  }
}