 #define RESPONSE_CALIBR_STATE   'i'
 #define RESPONSE_MONITOR_STATE  'V'
 #define RESPONSE_LAP0_STATE     'F'
+#define RESPONSE_END_SEQUENCE   'X'
 
 // send item byte constants
 // Must correspond to sequence of numbers used in "send data" switch statement

#define SEND_RACE_STATE     1
#define SEND_MIN_LAP_TIME   2
#define SEND_THRESHOLD      3
#define SEND_CURRENT_RSSI   4
#define SEND_ALL_LAPTIMES   5
#define SEND_SOUND_STATE    6
#define SEND_BAND           7
#define SEND_CALIBR_STATE   8
#define SEND_MONITOR_STATE  9
#define SEND_LAP0_STATE     10
// following itmes don't participate in "send all itmes" response
#define SEND_LAST_LAPTIMES  100
#define SEND_CALIBR_TIME    101
// special item that sends all subsequent items from 0 (see above)
#define SEND_ALL_DEVICE_STATE 255


                    onItemSent();
                }
                break;
            case 4: // SEND_ALL_LAPTIMES
                if (sendLapTimesIndex < newLapIndex) {
                    if (sendLaptimeToSerial(RESPONSE_LAPTIME, sendLapTimesIndex, lapTimes[sendLapTimesIndex])) {
                        sendLapTimesIndex++;
