2004-11-27 23:40:53

by Marco Trudel

[permalink] [raw]
Subject: [Bluez-users] inquiry scan problems

Hello everybody

After i noticed the problems (description follows), i updated the
software to the most recent versions. Now I have:
- kernel 2.6.8-24
- bluez-libs-2.11.tar.gz
- bluez-utils-2.11.tar.gz
- bluez-hcidump-1.15.tar.gz
- avetanabt-20041119 (http://sourceforge.net/projects/avetanabt/)
-> acer bt500 usb dongle

My goal is to get a list of all bluetooth devices in rainge. I do five
inquirys in a row (with one second break between two complete scans).
The problems now are:

- the inquiry doesn't always find all devices
that raises the question: how reliable/secure is it that all devices are
found in an inquiry? how possible is that one or more devices are missed?

- the fife inquirys sometimes stop in the middle and won't continue.
for example after starting the 3. inquiry, it never completes (comes to
[public void inquiryCompleted(int status)] (jsr82)

- [RemoteDevice].getFriendlyName(true) sometimes (well - in fact often)
returns the String "null" (not null object) instead of the real friendly
name. if i do a loop with getFriendlyName(true), after ~8 times it gets
the correct friendlyName...
the null (object) should only be returned if the hardware doesn't
support getting the friendlyName (but obviusly this works). i have no
idea why the "null" string is supposed to be returned...
I added the hcidump of a request with "null" returns... maybe someone of
you can do more with it than me...

- [RemoteDevice].getFrienlyName(true) returns a friendly name of another
device if multiple devices are in rainge.

- general question: what if multiple bluetooth devices are connected to
the computer. which level has to support that?
bluez / avetana (jsr82 implementation)?


I don't know which one of the problems are a subject of bluez.
If it's not a bluez subject, i would appreciate if someone could point
me to the source of the problem.

I assume the usb dongle is the problem here. Someone on this mailinglist
already mentioned that it's a crappy dongle. (thanks again for the time
you invested - you really helped me a lot!)
If it's the dongle again, what do other users here use? which ones work
reliably?

please let me know if you need additional informations...


kind regards
Marco Trudel



hcidump:
(please note, every friendlyName is (intentinally) requested twice.
--------------------
< HCI Command: Inquiry (0x01|0x0001) plen 5
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Result (0x02) plen 15
> HCI Event: Inquiry Complete (0x01) plen 1
> HCI Event: Command Complete (0x0e) plen 3
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Remote Name Req Complete (0x07) plen 255
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Complete (0x0e) plen 3
> HCI Event: Command Status (0x0f) plen 4
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Remote Name Req Complete (0x07) plen 255
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Complete (0x0e) plen 3
> HCI Event: Command Status (0x0f) plen 4
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Remote Name Req Complete (0x07) plen 255
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Complete (0x0e) plen 3
> HCI Event: Command Status (0x0f) plen 4
--------------------


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2004-11-28 06:59:13

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [Bluez-users] inquiry scan problems

Hi Marco,

> My goal is to get a list of all bluetooth devices in rainge. I do five
> inquirys in a row (with one second break between two complete scans).
> The problems now are:
>
> - the inquiry doesn't always find all devices
> that raises the question: how reliable/secure is it that all devices are
> found in an inquiry? how possible is that one or more devices are missed?
>
> - the fife inquirys sometimes stop in the middle and won't continue.
> for example after starting the 3. inquiry, it never completes (comes to
> [public void inquiryCompleted(int status)] (jsr82)
>
> - [RemoteDevice].getFriendlyName(true) sometimes (well - in fact often)
> returns the String "null" (not null object) instead of the real friendly
> name. if i do a loop with getFriendlyName(true), after ~8 times it gets
> the correct friendlyName...
> the null (object) should only be returned if the hardware doesn't
> support getting the friendlyName (but obviusly this works). i have no
> idea why the "null" string is supposed to be returned...
> I added the hcidump of a request with "null" returns... maybe someone of
> you can do more with it than me...
>
> - [RemoteDevice].getFrienlyName(true) returns a friendly name of another
> device if multiple devices are in rainge.
>
> - general question: what if multiple bluetooth devices are connected to
> the computer. which level has to support that?
> bluez / avetana (jsr82 implementation)?

can your reproduce it without using any JSR-82 stuff?

> I don't know which one of the problems are a subject of bluez.
> If it's not a bluez subject, i would appreciate if someone could point
> me to the source of the problem.
>
> I assume the usb dongle is the problem here. Someone on this mailinglist
> already mentioned that it's a crappy dongle. (thanks again for the time
> you invested - you really helped me a lot!)
> If it's the dongle again, what do other users here use? which ones work
> reliably?

This is the Zeevo TC2001 based dongle, right? If yes, then replace it,
because I won't rely on this hardware.

Regards

Marcel




-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://productguide.itmanagersjournal.com/
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users