python bluetooth - check connection status

Question

I am using the bluetooth module for python import bluetooth which I believe is the PyBluez package. I am able to connect, send, and receive just fine from the bluetooth.BluetoothSocket class but my application is completely blind when it comes to the status of the connection.

I want my application to disable certain functionality when the device is disconnected but there does not seem to be any BluetoothSocket.is_connected() methods of any kind. I would like it to detect changes in the bluetooth status as soon as they occur.

Usually there are multiple topics about something as simple as this, so apologies if this is a duplicate. I have searched this site multiple times for an answer but found nothing specific to python.

Answer 1

If your SO is linux, you could use the hcitool, which will tell you the status of your bluetooth devices.

Please find below a small Python snippet that can accomplish your need. You will need to know your bluetooth device's MAC:

import subprocess as sp

stdoutdata = sp.getoutput("hcitool con")

if "XX:XX:XX:XX:XX:XX" in stdoutdata.split():
    print("Bluetooth device is connected")

Hope this helps!

Answer 2

If you are using Linux, it's also possible to check whether the device is still available using BluetoothSocket's getpeername() method. This method (which is inherited from python's socket class) returns the remote address to which the socket is connected.

If the device is still available:

>>>sock.getpeername()
('98:C3:32:81:64:DE', 1)

If the device is not connected:

>>>sock.getpeername()
Traceback (most recent call last):
    File "<string>", line 3, in getpeername
_bluetooth.error: (107, 'Transport endpoint is not connected')

Therefore, to test if a socket is still connected to an actual device, you could use:

try:
    sock.getpeername()
    still_connected = True
except:
    still_connected = False