 
 const int PORT_SERVO = 18;
 const int STBD_SERVO = 15;
+const int AFT_THRUSTER = 12;
+const int PORT_THRUSTER = 14;
+const int STBD_THRUSTER = 13;
+
+const int MIN_THRUST = 1000;
+const int ZERO_THRUST = 1500;
+const int MAX_THRUST = 2000;
 
 const int PACKET_SIZE = 10;
 byte packet[PACKET_SIZE];
-
-const float POWER_CONVERSION = 9.0/127.0; // 90.0/127.0
 
 Servo aft_thruster;
 Servo port_thruster;

    SetPosition(PORT_SERVO, port_angle * ANGLE_CONVERSION);
    SetPosition(STBD_SERVO, stbd_angle * ANGLE_CONVERSION);

    aft_thruster.write(aft_power * POWER_CONVERSION + 90);
    port_thruster.write(port_power * POWER_CONVERSION + 90);
    stbd_thruster.write(stbd_power * POWER_CONVERSION + 90);
  }
}


  SetPosition(PORT_SERVO, 90 * ANGLE_CONVERSION);
  SetPosition(STBD_SERVO, 90 * ANGLE_CONVERSION);

  aft_thruster.attach(AFT_THRUSTER);
  port_thruster.attach(PORT_THRUSTER);
  stbd_thruster.attach(STBD_THRUSTER);

  aft_thruster.writeMicroseconds(ZERO_THRUST);
  port_thruster.writeMicroseconds(ZERO_THRUST);
  stbd_thruster.writeMicroseconds(ZERO_THRUST);
  
  pinMode(0, OUTPUT);
  digitalWrite(0, heartbeat);
