TOPIC: Keep getting 'device or resource busy' error when connecting

I have the Shoestring Astronomy BTEQ5 Bluetooth dongle, it pairs, connects and gets assigned to /dev/rfcomm0 with no issues in Ubuntu Mate on my Raspberry Pi 3. My other devices connect automatically (Canon DSLR and SSAG) when starting indi, but the mount will not connect.

I have an Orion Sirius EQ-G mount, and I've used the same BT dongle in windows to control the mount via EQMOD with very little trouble (just the normal 'getting windows to assign a comport' to the BT dongle).

I've tried changing all permissions to /dev/rfcomm0, making sure my user has access to the DIALOUT group, etc etc. At this point, I don't think it's a permission issue. But no matter what I do, even changing to a different port, as well as doing a symbolic link to /dev/ttyUSB0, nothing works. I always get the same error about not being able to connect to the port, device busy, yadda yadda yadda

Hope someone has some insight to this issue!

I have the exact same dongle and HEQ5 as well, and it works fine. You used the bluetooth app in Ubuntu to pair it? I created a video for StellarMate about this, but it should be applicable to your case as well:

Start watching at 03:40

Thanks. I've seen that video and have done exactly what was in it (saw where you posted this for someone else in another thread). Everything goes exactly as in the video except I get an error. I must be missing something else.

Took a SS in the hopes it helps a little? The BTEQ5 is paired, trusted and is set to /dev/rfcomm0. Any ideas what else I can do? I've actually gone back and reinstalled everything from scratch just in case I did something wrong the first time.

Greetings,

One thing you could try is to use lsof (list open files) This should show you what is using it, and give you a place to start.

Try this:

xsnrg wrote: Greetings,

One thing you could try is to use lsof (list open files) This should show you what is using it, and give you a place to start.

Try this:

sudo lsof /dev/rfcomm0

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
blueman-r 3423 root 6r CHR 216,0 0t0 59219 /dev/rfcomm0

As far as I can see, that's legit. If I kill that PID, it severs the connection to the BT.

I had similar issue recently and remember doing the below to fix it

sudo chown astroberry /dev/rfcomm0
sudo usermod -a -G dialout astroberry

Replace astroberry with your username.

tkottary wrote: I had similar issue recently and remember doing the below to fix it

sudo chown astroberry /dev/rfcomm0
sudo usermod -a -G dialout astroberry

Replace astroberry with your username.

Just tried that with no luck as well. I took the BTEQ5 and hooked it back up to my windows laptop, everything worked just fine with EQMOD there. I also tried it on my laptop running Linux Mint 18 and it would not stay connected. I could pair, but it would only stay connected a moment. I also could find no way in Mint to assign a com port, so that was no help...was really hoping Mint would help me, but the last thing I need right now is being sidetracked with another linux machine that this won't work on!

I think your problem is that "blueman-r" process as my system doesn't list any processes with "lsof /dev/rfcomm0" when not connected and indi_eqmod_telescope when it is. I don't use the bluetooth manager connect but have "rfcomm bind 0 20:16:xx:xx:xx:xx" in my startup scripts.

jpaana wrote: I think your problem is that "blueman-r" process as my system doesn't list any processes with "lsof /dev/rfcomm0" when not connected and indi_eqmod_telescope when it is. I don't use the bluetooth manager connect but have "rfcomm bind 0 20:16:xx:xx:xx:xx" in my startup scripts.

It appears Blueman is the graphical interface. I did not install it separately, I wonder if it's safe to just get rid of it?

(EDIT) So, blueman was the culprit. I uninstalled it and bound the BT to /dev/rfcomm0 manually and EKOS connected right away. Slewing controls worked just like EQMOD so all appears well...at least with this initial problem. Thanks for all the help!

I heard that in 18.04, the bluetooth stack is much more reliable. So hopefully it would be less of a pain in a few months. Notwithstanding that, I didn't face any issues here.. maybe I was lucky!

I have the same problem. I'm a real beginner.
Would you mind telling me the commands you used to bind the /dev/rfcomm ?
Thanks