Using an Arduino as an RC reciever module

i have a example ,,

// SERIAL INPUT R= ROLL T =TROTTLE P =PITCH A =AUX Y =YAW 
// INPUT WIL BE LIKE THIS TRUE SERIAL ,, 
// R100T200P200A0Y1024 AND 
#include <Servo.h> 
typedef enum {  NONE, GOT_T, GOT_Y, GOT_P, GOT_R,GOT_A} states;


states state = NONE;

unsigned int currentValue;
int trot =0;
int yaw =0;
int pitch =0;
int roll =0;
int aux =0;
int servo =0;
Servo myservo;

void setup ()
{
  Serial.begin (115200);
  state = NONE;
  myservo.attach(7); 
  myservo.write(0);
}  // end of setup
void processT (const unsigned int value)
{
  trot =value; 
} // end of processTHROTTLE

void processY (const unsigned int value)
{
  // do something with YAW 
  Serial.print ("YAW =");
  Serial.println (value);
  yaw =value;
} // end of processYAW

void processP (const unsigned int value)
{
  // do something with PITCH 
  Serial.print ("PITCH = ");
  Serial.println (value);
  pitch =value;  
} // end of processPITCH

void processR (const unsigned int value)
{
  // do something with ROLL
  Serial.print ("ROLL = ");
  Serial.println (value);
  roll =value;  
} // end of processROLL

void processA (const unsigned int value)
{
  // do something with AUX 
  Serial.print ("AUX = ");
  Serial.println (value);
  aux =value;  
} // end of processAUX
void handlePreviousState ()
{
  switch (state)
  {
  case GOT_T:
    processT (currentValue);
    break;
  case GOT_Y:
    processY (currentValue);
    Serial.println ("PPM YAW OUT");
    Serial.println (yaw);
    delay (100);
    break;
  case GOT_P:
    processP (currentValue);
    Serial.println ("PPM PITCH OUT");
    Serial.println (pitch);
    delay (100);
    break;
  case GOT_R:
    processR (currentValue);
    Serial.println ("PPM ROLL OUT");
    Serial.println (roll);
    delay (100);
    break;
  case GOT_A:
    processA (currentValue);
    Serial.println ("PPM AUX OUT");
    Serial.println (aux);
    delay (100);
    break;
  }  // end of switch  

  currentValue = 0; 
}  // end of handlePreviousState

void processIncomingByte (const byte c)
{
  if (isdigit (c))
  {
    currentValue *= 10;
    currentValue += c - '0';
  }  // end of digit
  else 
  {

    // The end of the number signals a state change
    handlePreviousState ();

    // set the new state, if we recognize it
    switch (c)
    {
    case 'Y':
      state = GOT_Y;
      break;
    case 'P':
      state = GOT_P;
      break;
    case 'T':
      state = GOT_T;
      Serial.println ("WHAHAHAHAHAH");
      break;
    case 'R':
      state = GOT_R;
      break;
    case 'A':
      state = GOT_A;
      break;
    default:
      state = NONE;
      break;
    }  // end of switch on incoming byte
  } // end of not digit  
} // end of processIncomingByte

void loop ()
{
  if (Serial.available ())
    processIncomingByte (Serial.read ());
    delay (1);
    myservo.write(trot);
  // do other stuff in loop as required
  
}  // end of loop