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 dataReceived from client and send this to modem..I'm struggling to get this to work.Any help will be highly appreciated! the code:

from twisted.internet import win32eventreactor
win32eventreactor.install()
from twisted.internet import reactor
from twisted.internet.serialport import SerialPort
from twisted.internet.protocol import Protocol, Factory
from twisted.python import log
import sys

log.startLogging(sys.stdout)
client_list = []#TCP clients connecting to me

class USBClient(Protocol):

    def connectionFailed(self):
        print "Connection Failed:", self
        reactor.stop()

    def connectionMade(self):
        print 'Connected to USB modem'
        USBClient.sendLine(self, 'AT\r\n')

    def dataReceived(self, data):
        print "Data received", repr(data)
        print "Data received! with %d bytes!" % len(data)
        #check & perhaps modify response and return to client
        for cli in client_list:
            cli.notifyClient(data)
        pass

    def lineReceived(self, line):
        print "Line received", repr(line)

    def sendLine(self, cmd):
        print cmd
        self.transport.write(cmd + "\r\n")

    def outReceived(self, data):
        print "outReceived! with %d bytes!" % len(data)
        self.data = self.data + data

class CommandRx(Protocol):

    def connectionMade(self):
        print 'Connection received from tcp..'
        client_list.append(self)

    def dataReceived(self, data):
        print 'Command receive', repr(data)
        #Build command, if ok, send to serial port
        #????
    def connectionLost(self, reason):
        print 'Connection lost', reason
        if self in client_list:
            print "Removing " + str(self)
            client_list.remove(self)

    def notifyClient(self, data):
        self.transport.write(data)

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

if __name__ == '__main__':
    reactor.listenTCP(8000, CommandRxFactory())
    SerialPort(USBClient(), 'COM8', reactor, baudrate='19200')
    reactor.run()

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()

Answer 2

Thanks, got it to work.Could not get def notifyAll to send data to my modem..did it like this:for cli in client_list: cli.transport.write(data)
new code:

import sys

from twisted.internet import reactor
from twisted.internet.protocol import Factory
from twisted.internet.protocol import Protocol
from twisted.internet.serialport import SerialPort
from twisted.python import log

log.startLogging(sys.stdout)
client_list = []#TCP clients connecting to me
usb_list = []

class USBClient(Protocol):

    def __init__(self, network):
        self.network = network
        self.usb_list = []

    def connectionFailed(self):
        print "Connection Failed:", self
        reactor.stop()

    def connectionMade(self):
        usb_list.append(self)
        print 'Connected to USB modem'
        USBClient.sendLine(self, 'AT\r\n')

    def dataReceived(self, data):
        print "Data received", repr(data)
        print "Data received! with %d bytes!" % len(data)

        for cli in client_list:
            cli.transport.write(data)
        #self.network.notifyAll(data)# !!AArgh..!Could not get this to work
        pass

    def lineReceived(self, line):
        print "Line received", repr(line)

    def sendLine(self, cmd):
        print cmd
        self.transport.write(cmd + "\r\n")

    def outReceived(self, data):
        print "outReceived! with %d bytes!" % len(data)
        self.data = self.data + data

class CommandRx(Protocol):


    def connectionMade(self):
        print 'Connection received from tcp..'
        client_list.append(self)

    def dataReceived(self, data):
        print 'Command receive', repr(data)
        for usb in usb_list:
            usb.transport.write(data)

    def connectionLost(self, reason):
        print 'Connection lost', reason
        if self in client_list:
            print "Removing " + str(self)
            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('yipee')

if __name__ == '__main__':

    tcpfactory = CommandRxFactory()
    reactor.listenTCP(8000, tcpfactory)
    SerialPort(USBClient(tcpfactory), '/dev/ttyUSB4', reactor, baudrate='19200')
    reactor.run()