PyBlueZ: Create multiple client connections

Question

I currently have a client/server pair coded against PyBlueZ. Right now the server can connect to sequential clients - it will work until its completed with a client, then it will begin listening for another client.

However, what I really want is to run client communication in separate threads so I have multiple clients at the same time. When I try a 2nd client connection, however, PyBlueZ advertises the same port that the first client is currently using. I am setting up connections like this:

self.port = bluetooth.PORT_ANY
print "Accepting clients..."
self.server_sock=bluetooth.BluetoothSocket( bluetooth.RFCOMM )
self.server_sock.bind(("",self.port))
self.server_sock.listen(5)
print "listening on port %d" % self.port

bluetooth.advertise_service( self.server_sock, MY_SERVICE, MY_UUID )

client_sock,address = self.server_sock.accept()
print "Accepted connection from ",address

commThread = ServerThread(client_sock, self.bn_id, self.bn_name, self.bn_thumbnail)

Again, this code works fine for sequential connections, but when I try it in parallel my client gets a "busy" response from the server's bluetooth system. On the client side I output the port its trying to connect to and it always shows port "1".

Is there a limitation in PyBlueZ which only allows for a single connection? Or am I doing something wrong here for parallel connections?

Answer 1

I think your problem has nothing to do with the Bluetooth client part of the code. You were right to show the Bluetooth server code. What you should try to change:

• Only advertise a service once, and once only (No need to advertise it for every server thread)

• Allocate a different server channel for each thread. (On RFCOMM connection, there usually is a RFCOMM manager which allocates a new server channel per each socket. I think in your case you might have to do that manually.) Change this code

  self.port = bluetooth.PORT_ANY
  

  Try channels 1, 2 and so on and see if it works! Then all you have to do is keep track of the allocated channels.

Please let me know if it worked!