Frame exchange protocol fixed size of 30 bytes like this :
    
 typedef struct  {
  int16_t  Begin  ;   // 2  Debut
  uint16_t Cpt ;      // 2  Compteur trame or Code
  float    gyro[3];   // 12 [Y, P, R]    gyro
  float    acc[3];    // 12 [x, y, z]    Acc
  int16_t  End ;      // 2  Fin
} _hatire;
_hat hat;


void setup() {
  Serial.begin(115200);
  // header frame
  hatire.Begin=0xAAAA;
  // Frame Number or Error code
  hat.Cpt=0;
  // footer frame
  hat.End=0x5555;
}

 
 void loop() {
   mpu.dmpGetYawPitchRoll(hatire.gyro);
   mpu.dmpAccXYZ(hatire.acc);
   // Send Trame to HATIRE PC
   Serial.write((byte*)&hatire,30);
   hatire.Cpt++;
   if (hatire.Cpt>999) {
       hatire.Cpt=0;
   }
   delay(1);      
}