Bluetooth rfcomm not working in Ubuntu Intrepid but Hardy

vimico · 12-14-2008, 05:09 PM

I have a simple Bluetooth GPS mouse which used to send GPS data (NMEA) via a Bluetooth serial link under Hardy, which stopped working under Intrepid

Code:

me@hardy:~$ sudo hcitool scan 
Scanning ...
	00:02:C7:7D:F5:17	BlueGPS 7DF517
me@hardy:~$ sudo rfcomm bind /dev/rfcomm0 00:02:C7:7D:F5:17 1
me@hardy:~$ ls -l /dev/rfcomm0
crw-rw---- 1 root dialout 216, 0 2008-12-14 23:15 /dev/rfcomm0

scan with hcitool for device address
create temporary rfcomm device to this unit
checking if the device was created (yes, I am member of the dialout group)

A simple python script connects to this device, reads and prints a line

Code:

me@hardy:~$ python
Python 2.5.2 (r252:60911, Jul 31 2008, 17:31:22) 
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a = open("/dev/rfcomm0","r")
>>> w = a.readline()
>>> print w
PGGA,221623.010,5555.4444,N,00333.2222,E,0,00,,129.7,M,0.0,M,,0000*42

>>> a.close()
>>> 
me@hardy:~$

Under Intrepid, the shell commands produce the same result, but I can't open that device (or any other utility):

Code:

me@intrepid:~$ python
Python 2.5.2 (r252:60911, Oct  5 2008, 19:24:49) 
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a = open("/dev/rfcomm0","r")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IOError: [Errno 110] Connection timed out: '/dev/rfcomm0'
>>>

/var/log/syslog shows:

Quote:

Dec 14 23:25:56 intrepid bluetoothd[6095]: Registered interface org.bluez.NetworkHub on path /org/bluez/hci0
Dec 14 23:25:56 intrepid bluetoothd[6095]: Registered interface org.bluez.NetworkRouter on path /org/bluez/hci0
Dec 14 23:25:56 intrepid bluetoothd[6095]: Registered interface org.bluez.Service on path /org/bluez/hci0
Dec 14 23:25:56 intrepid bluetoothd[6095]: Registered interface org.bluez.SerialProxyManager on path /org/bluez/hci0
Dec 14 23:25:56 intrepid bluetoothd[6095]: Adapter /org/bluez/hci0 has been enabled
Dec 14 23:25:56 intrepid bluetoothd[6095]: Starting security manager 0
Dec 14 23:28:26 intrepid kernel: [ 496.724082] hci_cmd_task: hci0 command tx timeout

Any hints?

MS3FGX · 12-14-2008, 05:24 PM

Your title says you are talking about Intrepid/Hardy, and then your post says Hardy/Gusty. Which one is it?

If you are talking about it working under Hardy and broken under Intrepid, I would say that it is probably because Intrepid switched over to the BlueZ 4.x API, which is completely different than the BlueZ 3.x software. Unfortunately this means that almost all Bluetooth software has to be updated to work with BlueZ 4.x.

Since 3.x is still the standard, a lot of developers have not yet updated their software. Also, and this is just my personal observation, the BlueZ 4.x documentation is incomplete and in general quite poor, so developers are not too enthusiastic about jumping on board.

You might want to look for information about BT GPS on BlueZ 4.x specifically, or perhaps even better, roll back your BlueZ version to the last 3.x release in the Ubuntu repositories (not sure how well this would work in practice, I am not an Ubuntu user personally).

vimico · 12-14-2008, 06:33 PM

Quote:

Originally Posted by MS3FGX

Your title says you are talking about Intrepid/Hardy, and then your post says Hardy/Gusty. Which one is it?

Sorry for the confusion.... I replaced all Gutsys with Intrepid...

As shown in the example, there is no special woodo involed. Just reading from a device. This seems such a basic function that I would have expected it too work no matter what.

Thank you for your info... I'm still hoping for a work-around.