convert the ip packet to and from RS-232 packet

[Jean-Paul Calderone]

On Mon, 9 Feb 2009 05:13:10 -0800 (PST), Li Han <lihang9999 at gmail.com> wrote:
>Hi, I need to use radio to connect two local ip network, each local
>network has a server computer which connects to a radio with RS-232
>interface.  I need to write a program to convert the local ip packet
>into RS-232 packet, so the radio can send packetes to the remote
>radio. I don't want to reinvent the wheel, is there anyone could give
>me some suggestions?

You can proxy between any two kinds of connection pretty easily with
Twisted (untested):

    from twisted.internet import serialport, protocol, reactor
    from twisted.protocols import portforward

    class SerialPortServer(portforward.Proxy):
        def connectionMade(self):
            # Stop the server, since only one thing can talk to the serial port
            # at a time.
            tcpPort.stopListening()

            # Hook up the proxy between this TCP connection and the serial port.
            self.peer = portforward.Proxy()
            self.peer.setPeer(self)
            self._serialPort = serialport.SerialPort(self.peer, '/dev/ttyS0', reactor)

    factory = protocol.ServerFactory()
    factory.protocol = SerialPortServer
    tcpPort = reactor.listenTCP(12345, factory)
    reactor.run()

Jean-Paul