Python Twisted receive command from TCP write to Serial device return response

Question

I\'ve managed to connect to usb modem and a client can connect via tcp to my reactor.listenTCP,the data received from modem will be send back to client. I\'m want to take dataRe

Answer 1

Your problem is not about twisted, but about python. Read this FAQ entry:

How do I make input on one connection result in output on another?

Thing is, if you want to send stuff to a TCP-connected client in your serial-connected protocol, just pass to the protocol a reference to the factory, so you can use that reference to make the bridge.

Here's some example code that roughly does this:

class USBClient(Protocol):
    def __init__(self, network):
        self.network = network
    def dataReceived(self, data):
        print "Data received", repr(data)
        #check & perhaps modify response and return to client
        self.network.notifyAll(data)
    #...    

class CommandRx(Protocol):
    def connectionMade(self):
        self.factory.client_list.append(self)
    def connectionLost(self, reason):
        if self in self.factory.client_list:
            self.factory.client_list.remove(self)

class CommandRxFactory(Factory):
    protocol = CommandRx
    def __init__(self):
        self.client_list = []

    def notifyAll(self, data):
        for cli in self.client_list:
            cli.transport.write(data)

When initializing, pass the reference:

tcpfactory = CommandRxFactory()
reactor.listenTCP(8000, tcpfactory)
SerialPort(USBClient(tcpfactory), 'COM8', reactor, baudrate='19200')
reactor.run()