Index: dialin/protocols/CAN.py
===================================================================
diff -u -r3bc7e000a3f98d87aa718d34f11305c82ab1f03c -ra641687dd05e3e6a24098fc9606fbb3dd11724b7
--- dialin/protocols/CAN.py	(.../CAN.py)	(revision 3bc7e000a3f98d87aa718d34f11305c82ab1f03c)
+++ dialin/protocols/CAN.py	(.../CAN.py)	(revision a641687dd05e3e6a24098fc9606fbb3dd11724b7)
@@ -471,7 +471,7 @@
         self.callback_listener_complete_messages = None 
         self.callback_listener_invalid_messages = None
         self.thread_pool_executor = ThreadPoolExecutor(max_workers=1)
-
+        self.transmitting_mutex = threading.Lock()
         # try to setup can bus and exit if the can bus has not ben setup to use.
         try:
             self.bus = socketcan.SocketcanBus(channel=can_interface)
@@ -750,7 +750,8 @@
 
             # A message can be longer than 8 bytes, so we need to split it
             # into 8 bytes packets.
-
+            # We are sending one message at a time on CAN
+            self.transmitting_mutex.acquire()
             number_of_packets = DenaliMessage.get_total_packets(padded_can_message_array)
 
             # We are sending one message at a time on CAN
@@ -767,6 +768,7 @@
                     self.do_log_can(packet, style="candump", channel=self.bus.channel, send=True)
                 self.bus.send(packet, 0)  # 0.1)
 
+            self.transmitting_mutex.release()
             # After all messages have been sent, we clear a flag
             self.send_event.clear()