fixed wrong packet reading

- could happen if started reading random trailing packet and first got stop flag

arduino/common/lib/CommsControl/CommsControl.cpp

@@ -74,8 +74,8 @@ void CommsControl::receiver() {
 
                 // find the boundary of frames
                 if (_last_trans[current_trans_index] == COMMS_FRAME_BOUNDARY) {
-                    // if not found start or if read the same byte as last time
-                    if (!_found_start || _start_trans_index == current_trans_index) {
+                    // if not found start or if read the same byte as last time or if read a random end first
+                    if (!_found_start || current_trans_index < _start_trans_index + 6 ) {
                         _found_start = true;
                         _start_trans_index = current_trans_index;
                     } else {

raspberry-dataserver/CommsControl.py

@@ -36,6 +36,7 @@ class CommsControl():
         
         # needed to find packet frames
         self._received = []
+        self._receivedStart = 0
         self._foundStart = False
         self._timeLastTransmission = int(round(time.time() * 1000))
         
@@ -136,9 +137,9 @@ class CommsControl():
             # TODO: this could be written in more pythonic way
             # force read byte by byte
             self._received.append(byte)
-#             logging.debug(byte)
+#             logging.info(byte)
             # find starting flag of the packet
-            if not self._foundStart and byte == bytes([0x7E]):
+            if byte == bytes([0x7E]) and ((len(self._received) < self._receivedStart + 6) or not self._foundStart ):
                 self._foundStart    = True
                 self._receivedStart = len(self._received)
             # find ending flag of the packet