Running bluez on Raspberry Pi

Running bluez on Raspberry Pi

[Neil Martin]

I'm new to bluez and fairly green with Bluetooth in general.  I have
built 5.30 on a Raspberry PI 2 running raspbian wheezy.  Here's the
configure command that I used (arrived at by experimentation and
Googling for various build problems I encountered):

LDFLAGS=-lrt ./configure --disable-systemd --enable-experimental
--enable-maintainer-mode


The hci tools seem to work as expected.  Also btgatt-client works - I
am able to connect to a BLE heart rate monitor and I see the HR
related services.


However, btgatt-server does not seem to do anything, but no errors
reported either.  I'm running it like this:

sudo ./btgatt-server -r

and get this as the only output:

Started listening on ATT channel. Waiting for connections


I'm assuming that I should be seeing this advertising when I run
hcitool lescan?  I don't see anything.  Also btmon shows no activity
when I run btgatt-server.


Additionally, if I try to run bluetoothd, I get the following output
which doesn't look good!


sudo ./bluetoothd -nE

bluetoothd[19968]: Bluetooth daemon 5.30
bluetoothd[19968]: Starting SDP server
bluetoothd[19968]: Bluetooth management interface 1.7 initialized
bluetoothd[19968]: Failed to obtain handles for "Service Changed" characteristic
bluetoothd[19968]: Not enough free handles to register service
bluetoothd[19968]: Error adding Link Loss service
bluetoothd[19968]: Not enough free handles to register service
bluetoothd[19968]: Not enough free handles to register service
bluetoothd[19968]: Not enough free handles to register service
bluetoothd[19968]: Current Time Service could not be registered
bluetoothd[19968]: gatt-time-server: Input/output error (5)
bluetoothd[19968]: Not enough free handles to register service
bluetoothd[19968]: Not enough free handles to register service


I've done plenty of googling and not finding anything useful, so I'm
hoping that someone here will have some insight.

Thanks, Neil

Re: Running bluez on Raspberry Pi

[Arman Uguray]

Hi Neil,

> On Sun, Apr 19, 2015 at 3:34 PM, Neil Martin <neil@vnp.com> wrote:
> I'm new to bluez and fairly green with Bluetooth in general.  I have
> built 5.30 on a Raspberry PI 2 running raspbian wheezy.  Here's the
> configure command that I used (arrived at by experimentation and
> Googling for various build problems I encountered):
>
> LDFLAGS=-lrt ./configure --disable-systemd --enable-experimental
> --enable-maintainer-mode
>
>
> The hci tools seem to work as expected.  Also btgatt-client works - I
> am able to connect to a BLE heart rate monitor and I see the HR
> related services.
>
>
> However, btgatt-server does not seem to do anything, but no errors
> reported either.  I'm running it like this:
>
> sudo ./btgatt-server -r
>
> and get this as the only output:
>
> Started listening on ATT channel. Waiting for connections
>
>
> I'm assuming that I should be seeing this advertising when I run
> hcitool lescan?  I don't see anything.  Also btmon shows no activity
> when I run btgatt-server.

Nope, btgatt-server doesn't configure anything related to advertising;
it simply sets up and attaches a GATT server to a listening L2CAP
socket on the ATT channel. So you need to set up advertising
separately, e.g. by running 'btmgmt advertising on' or 'btmgmt
add-adv'.

Note that you usually don't want to run btgatt-server while bluetoothd
is running since they will interfere with eachother.

>
>
> Additionally, if I try to run bluetoothd, I get the following output
> which doesn't look good!
>
>
> sudo ./bluetoothd -nE
>
> bluetoothd[19968]: Bluetooth daemon 5.30
> bluetoothd[19968]: Starting SDP server
> bluetoothd[19968]: Bluetooth management interface 1.7 initialized
> bluetoothd[19968]: Failed to obtain handles for "Service Changed" characteristic
> bluetoothd[19968]: Not enough free handles to register service
> bluetoothd[19968]: Error adding Link Loss service
> bluetoothd[19968]: Not enough free handles to register service
> bluetoothd[19968]: Not enough free handles to register service
> bluetoothd[19968]: Not enough free handles to register service
> bluetoothd[19968]: Current Time Service could not be registered
> bluetoothd[19968]: gatt-time-server: Input/output error (5)
> bluetoothd[19968]: Not enough free handles to register service
> bluetoothd[19968]: Not enough free handles to register service
>

We really need to clean these up. Basically bluetoothd fails to
register all the experimental local services since we changed the
internal plumbing to the new shared stack. Fwiw these are all plugins
that we are deprecating and the actual local GATT server will work
regardless.

Also, if you want the daemon running, I suggest using the GATT D-Bus
API for hosting your own services.

>
> I've done plenty of googling and not finding anything useful, so I'm
> hoping that someone here will have some insight.
>
> Thanks, Neil
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Thanks!
Arman

Re: Running bluez on Raspberry Pi

[Neil Martin]

Hi Arman,

Many thanks for the reply!

On Mon, Apr 20, 2015 at 5:29 PM, Arman Uguray <armansito@chromium.org> wrote:
> Hi Neil,
>
>> On Sun, Apr 19, 2015 at 3:34 PM, Neil Martin <neil@vnp.com> wrote:
>> I'm new to bluez and fairly green with Bluetooth in general.  I have
>> built 5.30 on a Raspberry PI 2 running raspbian wheezy.  Here's the
>> configure command that I used (arrived at by experimentation and
>> Googling for various build problems I encountered):
>>
>> LDFLAGS=-lrt ./configure --disable-systemd --enable-experimental
>> --enable-maintainer-mode
>>
>>
>> The hci tools seem to work as expected.  Also btgatt-client works - I
>> am able to connect to a BLE heart rate monitor and I see the HR
>> related services.
>>
>>
>> However, btgatt-server does not seem to do anything, but no errors
>> reported either.  I'm running it like this:
>>
>> sudo ./btgatt-server -r
>>
>> and get this as the only output:
>>
>> Started listening on ATT channel. Waiting for connections
>>
>>
>> I'm assuming that I should be seeing this advertising when I run
>> hcitool lescan?  I don't see anything.  Also btmon shows no activity
>> when I run btgatt-server.
>
> Nope, btgatt-server doesn't configure anything related to advertising;
> it simply sets up and attaches a GATT server to a listening L2CAP
> socket on the ATT channel. So you need to set up advertising
> separately, e.g. by running 'btmgmt advertising on' or 'btmgmt
> add-acv'.

Got it.  Thanks for pointing me at btmgmt - I wasn't aware of that tool.

I did try the btmgmt advertising commands without success and I wonder
if you could answer a few questions on this.

1) Seems like I needed to issue a 'btmgmt le on' before the 'btmgmt
advertising on' otherwise it fails.  Does that make sense?

2) What does  'btmgmt advertising on' do?  Is that command needed to
switch advertising on before issuing 'btmgt add-adv"?

3) I played around with the add-adv command and it spits out a message
if you give it params that it doesn't like.  That message contains an
example invocation, so I tried that.  Here's the command and the error
message:

sudo ./btmgmt add-adv -u 180d -u 180f -d 080954657374204C45 1
Add Advertising failed with status 0x01 (Unknown Command)

4) I also noticed that btmgmt has some other useful commands.  One in
particular that interested me was 'find-service'.  I get an error with
this too:

sudo ./btmgmt find-service -u 180d
Start Service Discovery failed: status 0x01 (Unknown Command)

Btw, 'btmgmt find' does work.


Now back to btgatt-server :)

Now I understand why I wasn't seeing any advertising; is it the case
that I should be able to connect to it using bggatt-client?  I tried
this from a different machine while running 'sudo ./btgatt-server
-rv':

sudo ./btgatt-client -i hci0 -d 5C:F3:70:65:CF:E6 -v
btgatt-client: Opening L2CAP LE connection on ATT channel:
src: 5C:F3:70:64:FB:97
dest: 5C:F3:70:65:CF:E6
Connecting to device... Failed to connect: Transport endpoint is not connected

>
> Note that you usually don't want to run btgatt-server while bluetoothd
> is running since they will interfere with each other.

I figured that might be the case.  Btw, I noticed when I cntrl C out
of bluetoothd that my bluetooth interface goes down.  Is that
expected?

I know that's a lot of stuff, but I'm hoping there might be a common
thread to the issues I'm hitting.

Thanks again!

Neil


>
>>
>>
>> Additionally, if I try to run bluetoothd, I get the following output
>> which doesn't look good!
>>
>>
>> sudo ./bluetoothd -nE
>>
>> bluetoothd[19968]: Bluetooth daemon 5.30
>> bluetoothd[19968]: Starting SDP server
>> bluetoothd[19968]: Bluetooth management interface 1.7 initialized
>> bluetoothd[19968]: Failed to obtain handles for "Service Changed" characteristic
>> bluetoothd[19968]: Not enough free handles to register service
>> bluetoothd[19968]: Error adding Link Loss service
>> bluetoothd[19968]: Not enough free handles to register service
>> bluetoothd[19968]: Not enough free handles to register service
>> bluetoothd[19968]: Not enough free handles to register service
>> bluetoothd[19968]: Current Time Service could not be registered
>> bluetoothd[19968]: gatt-time-server: Input/output error (5)
>> bluetoothd[19968]: Not enough free handles to register service
>> bluetoothd[19968]: Not enough free handles to register service
>>
>
> We really need to clean these up. Basically bluetoothd fails to
> register all the experimental local services since we changed the
> internal plumbing to the new shared stack. Fwiw these are all plugins
> that we are deprecating and the actual local GATT server will work
> regardless.
>
> Also, if you want the daemon running, I suggest using the GATT D-Bus
> API for hosting your own services.
>
>>
>> I've done plenty of googling and not finding anything useful, so I'm
>> hoping that someone here will have some insight.
>>
>> Thanks, Neil
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> Thanks!
> Arman