I have been working on the problem of echo in GSM calls and I seem to
have boiled the issue down to a hardware problem. There is I think the
possibility there is a mechanical problem with the case design where
audio from the handset speaker ends up entering the handset mic far
too
easily causing echos.
I suspect this issue also affects GTA01, its just no-one used that
as a
phone much.
I have attached the private email thread that occurred to lead up to
this issue. It would be useful if more people had ideas.
Graeme
did you try using your A5 as a phone?
If someone else calls you on your Neo, and talks to you, do they hear
an echo of themselves?
We have found the Neo to produce quite a bit of echo.
Sean Chiang thinks it's a hardware problem.
Can you look into this and let me know what you think?
Thanks and Best Regards,
Wolfgang
On Mar 2, 2008, at 7:51 PM, Graeme Gregory wrote:
On Sun, 2 Mar 2008 09:24:57 +0800
Wolfgang Spraul <[EMAIL PROTECTED]> wrote:
Graeme -
did you try using your A5 as a phone?
If someone else calls you on your Neo, and talks to you, do they
hear an echo of themselves?
We have found the Neo to produce quite a bit of echo.
Sean Chiang thinks it's a hardware problem.
Can you look into this and let me know what you think?
Thanks and Best Regards,
Wolfgang
Hi, I haven't made a phone call yet.
Sean could you send me the .state files you used, just in case they
have been tuned differently that the one in monotone repo.
Graeme
Guys I don't know what your use cases are so it is your call.
well, at least we find out the ugly truth now.
Let's QUICKLY converge on a set of use cases as the default, plus some
'diffs' / 'modifications' for special use cases.
I don't even like the idea of two statefiles (monotone + svn)? Why
that?
Please do not put a second set into svn.
The one in monotone can become the Openmoko gold standard. If it's not
right for someone, let's start the discussion.
****----> And please from now on send unified diff snippets against
the monotone gold standard around!!! <-----*****
So other people can understand what you are trying to CHANGE, rather
than just seeing your huge new statefiles.
Wolfgang
On Mar 3, 2008, at 3:28 AM, Graeme Gregory wrote:
On Sun, 2 Mar 2008 22:41:23 +0800
Wolfgang Spraul <[EMAIL PROTECTED]> wrote:
Ouch. .state files.
We have way too many .state files flying around as e-mail
attachments.
Please no more!
Can we get a definitive and working set of .state files into a
central repository?
Please DO NOT SEND .STATE FILES AS ATTACHMENTS ANYMORE!!!
This is totally confusing and we will never ever converge on a
working set like that.
As a worst case I think unified diff snippets against mainline are
acceptable :-)
Wolfgang
I have been treating the statefiles stored in monotone as the golden
standard.
I would be happy to move these to svn if that is easier for guys in
Taiwan to make use of. I know they do a lot of work outside of
monotone.
Guys I don't know what your use cases are so it is your call.
Graeme
http://svn.openmoko.org/trunk/src/target/audio/
-Sean Chiang
Graeme already put it in
https://svn.openmoko.org/trunk/src/target/OM-2007.2/misc/alsa-state-files/fic-gta02
So Sean removed the `audio' folder and let's use the ones under misc.
Regards,
John
On Mar 4, 2008, at 11:58 AM, John Lee wrote:
On Tue, Mar 04, 2008 at 11:35:06AM +0800, Sean Chiang wrote:
HI! Graeme,
http://svn.openmoko.org/trunk/src/target/audio/
-Sean Chiang
Graeme already put it in
https://svn.openmoko.org/trunk/src/target/OM-2007.2/misc/alsa-state-files/fic-gta02
So Sean removed the `audio' folder and let's use the ones under misc.
Regards,
John
On Mar 4, 2008, at 6:37 PM, Graeme Gregory wrote:
On Tue, 04 Mar 2008 11:35:06 +0800
Sean Chiang <[EMAIL PROTECTED]> wrote:
HI! Graeme,
http://svn.openmoko.org/trunk/src/target/audio/
alsa state files for gta02 are now here.
I think I have solved the echo in gsmhandset.state, I have also
routed
the DAC to handset speaker for this state so phone beeps etc still
get
routed to user.
You will need a kernel later than 4153 for these states to apply as I
found an upstream bug in codec driver which is now fixed.
Let me know how you get on with the states.
Graeme
On Tue, 04 Mar 2008 11:35:06 +0800
Sean Chiang <[EMAIL PROTECTED]> wrote:
HI! Graeme,
http://svn.openmoko.org/trunk/src/target/audio/
alsa state files for gta02 are now here.
I think I have solved the echo in gsmhandset.state, I have also
routed
the DAC to handset speaker for this state so phone beeps etc still
get
routed to user.
You will need a kernel later than 4153 for these states to apply as I
found an upstream bug in codec driver which is now fixed.
Let me know how you get on with the states.
Spoke too soon, retested on my hardware this morning with a totally
fresh build and the echo is still there. Not sure why I didn't hear it
last night but phoning yourself isn't the best strategy so maybe I
just
missed in.
Graeme
Too much sound is making its way round the case from speaker to
microphone. I had the speaker volume turned down last night and echo
no
longer happens if you do this.
control.4 {
comment.access 'read write'
comment.type INTEGER
comment.count 2
comment.range '0 - 127'
iface MIXER
name 'Speaker Playback Volume'
value.0 88
value.1 88
}
Is the control to play with. Im not sure if there is anything you guys
can do hardware wise? Surround speaker with padding or something?
I don't really have a good setup here to test this stuff.
Graeme
On Mar 4, 2008, at 7:49 PM, Graeme Gregory wrote:
On Tue, 4 Mar 2008 11:44:21 +0000
Graeme Gregory <[EMAIL PROTECTED]> wrote:
Spoke too soon, retested on my hardware this morning with a totally
fresh build and the echo is still there. Not sure why I didn't hear
it
last night but phoning yourself isn't the best strategy so maybe I
just missed in.
Sorry flooding you with emails I think I found the cause and why I
thought I had solved it.
Too much sound is making its way round the case from speaker to
microphone. I had the speaker volume turned down last night and echo
no
longer happens if you do this.
control.4 {
comment.access 'read write'
comment.type INTEGER
comment.count 2
comment.range '0 - 127'
iface MIXER
name 'Speaker Playback Volume'
value.0 88
value.1 88
}
Is the control to play with. Im not sure if there is anything you
guys
can do hardware wise? Surround speaker with padding or something?
I don't really have a good setup here to test this stuff.
Graeme
