On 04/05/2010 12:39 PM, Chris Cusack wrote:

Probably another newbie question but after much effort I am not progressing on the following.

I am trying to design a system where I have a microprocessor periodically feeding data on a serial connection to a server script. I would then like the server script to notify one or more client scripts of the changed data across a local network. I have tried a few simple tcp server and client script examples which communicate well for a single call but do not seem to suit my application which is not client event driven. I considered having each client connect to the server every ?? seconds to query for new data but there may be a better way.

Perhaps I'm misunderstanding, but it's pretty simple. Just have the clients connect & stay connected. Keep a list of currently connected clients somewhere (see below) and every time you receive data on the serial port, write it out to all the clients. For example: # ack, global variable! client_list = [] class MyProtocol(Protocol): def connectionMade(self): client_list.append(self) def connectionLost(self, reason): if self in client_list: client_list.remove(self) def notifyClient(self, data): # you will probably want some framing here e.g. Netstring, len+data self.transport.write(data) class ServerProto(Protocol): def dataReceived(self, data): for cli in client_list: cli.notifyClient(data) ...or am I misunderstanding you?

On 04/05/2010 12:39 PM, Chris Cusack wrote:

Probably another newbie question but after much effort I am not progressing on the following.

I am trying to design a system where I have a microprocessor periodically feeding data on a serial connection to a server script. I would then like the server script to notify one or more client scripts of the changed data across a local network. I have tried a few simple tcp server and client script examples which communicate well for a single call but do not seem to suit my application which is not client event driven. I considered having each client connect to the server every ?? seconds to query for new data but there may be a better way.

Perhaps I'm misunderstanding, but it's pretty simple. Just have the clients connect & stay connected. Keep a list of currently connected clients somewhere (see below) and every time you receive data on the serial port, write it out to all the clients. For example: # ack, global variable! client_list = [] class MyProtocol(Protocol): def connectionMade(self): client_list.append(self) def connectionLost(self, reason): if self in client_list: client_list.remove(self) def notifyClient(self, data): # you will probably want some framing here e.g. Netstring, len+data self.transport.write(data) class ServerProto(Protocol): def dataReceived(self, data): for cli in client_list: cli.notifyClient(data) ...or am I misunderstanding you?