host = '192.168.100.45'
clientSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#clientSocket.setblocking(0)
#clientSocket.settimeout(2)
#fcntl.fcntl(clientSocket, fcntl.F_SETFL, os.O_NONBLOCK)
#clientSocket.connect( ( host, 8902 ) )
#-------------------------------------------------------------------------------------------------------------------------------
class pingTimer():
   def __init__(self,t,hFunction):
      self.t=t
      self.hFunction = hFunction
      self.thread = Timer(self.t,self.handle_function)
   def handle_function(self):
      self.hFunction()
      self.thread = Timer(self.t,self.handle_function)
      self.thread.start()
   def start(self):
      self.thread.start()
   def cancel(self):
      self.thread.cancel()
#-------------------------------------------------------------------------------------------------------------------------------
def send_ping():
#    global clientSocket
    print ("send ping")
    try:
        clientSocket.send(b'33333{"cmd":"ping","rid":"RID000000"}')
    except:
      print("error send ping, socket close")
      clientSocket.close()
      connect()      
#    timer.start()    
#-------------------------------------------------------------------------------------------------------------------------------	
def connect():
    global clientSocket
    try:
        print( "try to connected to device" )
        clientSocket.connect( ( host, 8902 ) )
        clientSocket.listen(1)
#        fcntl.fcntl(clientSocket, fcntl.F_SETFL, os.O_NONBLOCK)
        connected = True
        print ("connected")
    except socket.error:
        connected = False  
        clientSocket = socket.socket()
        print( "connection lost... reconnecting" )
        while not connected:
            try:
                clientSocket.connect( ( host, 8902 ) )  
                connected = True  
                print( "re-connection successful" )
            except socket.error:  
                sleep(2)
                print("try to reconnect.....")
#-------------------------------------------------------------------------------------------------------------------------------
def recv_msg():
    global clientSocket
    while True:
        recv_msg = clientSocket.recv(1024)
        if not recv_msg:
            sys.exit(0)
        recv_msg = recv_msg.decode()
        print('message recive')
        print(recv_msg)
#-------------------------------------------------------------------------------------------------------------------------------
# main start
#connect()
t_ping = pingTimer(5,send_ping)
t_ping.start()
#t_listen = threading.Thread(target = recv_msg)
connect()
#t_listen.start()
while True:
    recv_msg()
#    print("while1")
#     print ('recv')