My VoIP experience in Freerunner

Benjamin Deering ben_deering at
Wed Aug 31 01:51:05 CEST 2011

This is the first I have heard of removing the case screws to reduce 
echo.  Has this worked for anyone else?
On 08/29/2011 03:13 PM, Paul Fertser wrote:
> Hi,
> Thanks for sharing the valueable info :)
> Tiago Bortoletto Vaz<tiago at>  writes:
>>   • I was not able to have default Freerunner headset working on an
>>   acceptable quality. Help will be very welcome.
> I think the voip-handset state file is supposed to be used with the
> handset (i.e. builtin mic and speaker) rather than with the
> headset. You'd need to study the routing diagram[1] to see what
> changes are needed to get a voip-headset setup.
> To check if it's working, you can simply load the statefile and then
> use ``arecord'' to record a sample file, scp it to your PC and check
> the levels and quality. Then scp some other known to be good file from
> PC to FR and use ``aplay'' to check the playback quality.
> Also, make sure you're not CPU-bound. As s3c2442 lacks an FPU, you
> probably should avoid codecs that require floating point operations,
> and also probably you might need to disable echo cancellation and/or
> silence detection.
> Be warned though, afaict the FR case (especially if you have both
> screws properly secured, i personally use my device without those for
> several years without any issues) provokes echo, so you might need to
> find an acceptable way (yet-to-be-discovered hardware mod or software)
> to do echo cancellation.
> [1]

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