struct tframe
          {
          uint8_t Startmark;
          uint8_t Engine_Speed;
          uint8_t ADR02;
          uint8_t Throttle;
          uint8_t AirTemp;
          uint8_t WaterTemp;
          uint8_t IgnitionTime;
           uint8_t ADCR13;
           uint8_t ADCR14;
           uint8_t ADCR17;
           uint8_t ADCR18;
           uint8_t ADCR15;
           uint8_t ADCR16;
            uint8_t ADCR08;
            uint8_t O_21;
            uint8_t O_22;
            uint8_t CarSpeed;
            uint8_t GearCalc;
            uint8_t Error1;
            uint8_t Error2;
            uint8_t CRC;
          };
tframe Frame;

uint8_t *startpoint;


void setup()
{
startpoint=&Frame.Startmark;

}

bool readframe()
{
static  uint8_t index;
             while (Serial.available())
                       {
                        uint8_t c=Serial.read();

                    if (c!=0x55 && index==0) return false;

                        *startpoint=c;
                         startpoint++;
                         index++;
                          if (index>20)
                                      {
                                      startpoint=&Frame.Startmark;
                                      index=0;
                                      return true;
                                      }

    }

}

void loop()

{
 if (readframe()) {

                   }

}