 
  The circuit:
  Two devices which communicate serially are needed.
- * First serial device's TX attached to digital pin 2, RX to pin 3
- * Second serial device's TX attached to digital pin 4, RX to pin 5
+ * First serial device's TX attached to digital pin 10(RX), RX to pin 11(TX)
+ * Second serial device's TX attached to digital pin 8(RX), RX to pin 9(TX)
 
  Note:
  Not all pins on the Mega and Mega 2560 support change interrupts,

 */

#include <SoftwareSerial.h>
// software serial #1: TX = digital pin 10, RX = digital pin 11
SoftwareSerial portOne(10, 11);

// software serial #2: TX = digital pin 8, RX = digital pin 9
// on the Mega, use other pins instead, since 8 and 9 don't work on the Mega
SoftwareSerial portTwo(8, 9);


 8, 9, 10, 11, 14 (MISO), 15 (SCK), 16 (MOSI).

 created 18 Apr. 2011
 modified 19 March 2016
 by Tom Igoe
 based on Mikal Hart's twoPortRXExample

