SoftwareSerial/SoftwareSerial.ino

Uses a pin other than TX to connect to S1.

// Software Serial Sample
// Copyright (c) 2012 Dimension Engineering LLC
// See license.txt for license details.

#include <SoftwareSerial.h>
#include <SyRenSimplified.h>

SoftwareSerial SWSerial(NOT_A_PIN, 11); // RX on no pin (unused), TX on pin 11 (to S1).
SyRenSimplified SR(SWSerial); // Use SWSerial as the serial port.

void setup()
{
  SWSerial.begin(9600);
}

void loop()
{
  int power;
  
  // Ramp from -127 to 127 (full reverse to full forward), waiting 20 ms (1/50th of a second) per value.
  for (power = -127; power <= 127; power ++)
  {
    SR.motor(power);
    delay(20);
  }
  
  // Now go back the way we came.
  for (power = 127; power >= -127; power --)
  {
    SR.motor(power);
    delay(20);
  }
}