inquiry scan problems

Bluez-users Marco Trudel 2 participants 2 messages Nov 27, 2004 – Nov 28, 2004 Bluetooth drivers

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Marco Trudel

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2004-11-27 23:40 UTC #0 lore raw

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

Quoted 5 lines

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

Quoted 8 lines

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