#include <HardwareSerial.h>

HardwareSerial SerialPort(2); // use UART2


void setup()  
{
  SerialPort.begin(15200, SERIAL_8N1, 16, 17); 
} 
void loop()  
{ 
  SerialPort.digitalWrite(15, HIGH);
  delay(1000);
  SerialPort.digitalWrite(15, LOW);
  delay(1000);
}