meerstetterTEC: Fix packet sequence number overflow

meerstetterTEC.py

@@ -95,7 +95,7 @@ class MeCom:
         return packet[0:1], int(packet[1:3], 16), int(packet[3:7], 16), packet[7:]
 
     def send(self, msg):
-        self.seqno += 1
+        self.seqno = (self.seqno + 1) & 0xFFFF
         payload = self.pack(HOST, self.address, self.seqno, msg)
         crc = self.crc(payload)
         self.conn.write(payload + crc + EOF)