Can't discover service created with PyBluez

Question

I'm trying to make a simple bluetooth service on Python using PyBluez and looks like it works, but I can't find that service with neither my phone, nor with PyBluez itself. I'm able to discovery my phone bluetooth when I do search with PyBluez, but not the server created with PyBluez. What's wrong with the code bellow?

import bluetooth

server_sock=bluetooth.BluetoothSocket( bluetooth.RFCOMM )

port = 0 # automatically choose port
server_sock.bind(("",port))
server_sock.listen(1)

uuid = "1e0ca4ea-299d-4335-93eb-27fcfe7fa848"
bluetooth.advertise_service( server_sock, "FooBar Service", uuid )

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

data = client_sock.recv(1024)
print "received [%s]" % data

client_sock.close()
server_sock.close()

I'm enabling service visibility with hciconfig hci0 piscan, so my phone is able to find a bluetooth device with name of my PC, but not the service I've created (I mean FooBar Service). Also I can't find my service using sdptool browse command.

Do I misunderstand something? How to connect to the service I've created?

update

Here is the below mentioned code result executed on my Windows 7 PC with D-Link Bluetooth adapter.

update

Finally it worked when I run client from another computer. It doesn't work locally, but why I can't discover this service from any device? Is there anything special I should do to make it behave like a normal Bluetooth service?

Answer 1

I was able to resolve this issue by changing the address argument of bluetooth.find_service to localhost. This is a special case that allows you to search for local SDP, https://people.csail.mit.edu/albert/bluez-intro/x290.html.

Answer 2

First of all your code it's not a service it's a Server that uses uses RFCOMM sockets.

It's very similar to the use of python socket programming (you can read more here)

I'll use a simple example from the PyBluez documentation:

Server part:

from bluetooth import *

server_sock=BluetoothSocket( RFCOMM )
server_sock.bind(("",PORT_ANY))
server_sock.listen(1)

port = server_sock.getsockname()[1]

uuid = "94f39d29-7d6d-437d-973b-fba39e49d4ee"

advertise_service( server_sock, "SampleServer",
                   service_id = uuid,
                   service_classes = [ uuid, SERIAL_PORT_CLASS ],
                   profiles = [ SERIAL_PORT_PROFILE ])

print("Waiting for connection on RFCOMM channel %d" % port)

client_sock, client_info = server_sock.accept()

print("Accepted connection from ", client_info)

#this part will try to get something form the client
# you are missing this part - please see it's an endlees loop!!
try:
    while True:
        data = client_sock.recv(1024)
        if len(data) == 0: break
        print("received [%s]" % data)

# raise an exception if there was any error
except IOError:
    pass

print("disconnected")

client_sock.close()
server_sock.close()

Client Part (copy paste for the docs):

from bluetooth import *
import sys

if sys.version < '3':
    input = raw_input

addr = None

if len(sys.argv) < 2:
    print("no device specified.  Searching all nearby bluetooth devices for")
    print("the SampleServer service")
else:
    addr = sys.argv[1]
    print("Searching for SampleServer on %s" % addr)

# search for the SampleServer service
uuid = "94f39d29-7d6d-437d-973b-fba39e49d4ee"
service_matches = find_service( uuid = uuid, address = addr )

if len(service_matches) == 0:
    print("couldn't find the SampleServer service =(")
    sys.exit(0)

first_match = service_matches[0]
port = first_match["port"]
name = first_match["name"]
host = first_match["host"]

print("connecting to \"%s\" on %s" % (name, host))

# Create the client socket
sock=BluetoothSocket( RFCOMM )
sock.connect((host, port))

print("connected.  type stuff")
while True:
    data = input()
    if len(data) == 0: break
    sock.send(data)

sock.close()

Your Problem:

I can't see any client code, you need to create a client and to connect the server.

You need to change it just like above, run the Server and then the Client.

Then you will see at the server the client connection.

Another useful link is here it really helped me.

Edit:

Since my current desktop doesn't have BT it's a bit tricky.

There's a great example for BlueZ server-client here at the bottom.

It is using MAC address:

Server Code: change the hostMACAddress param - it's your adapter mac address

Client Code: change serverMACAddress to what you wrote at 'hostMACAddress'