Refactor net-to-serial.py to support JMRI

daemons/net-to-serial.py

@@ -18,9 +18,12 @@ class SerialDaemon:
             pass
 
     async def handle_echo(self, reader, writer):
+        while 1:  # keep connection to client open
             data = await reader.read(100)
-        addr = writer.get_extra_info('peername')
+            if not data:  # client has disconnected
+                break
 
+            addr = writer.get_extra_info('peername')
             logging.info("Received {} from {}".format(data, addr[0]))
 
             self.ser.write(data)
@@ -33,8 +36,8 @@ class SerialDaemon:
             writer.write(response)
             await writer.drain()
 
-        logging.info("Close the connection")
         writer.close()
+        await writer.wait_closed()
 
     async def return_board(self):
         self.ser.write(b'<s>')