BT headset on Qtopia how?

Brad Midgley bmidgley at gmail.com
Tue Aug 12 07:34:23 CEST 2008


Guys

fwiw, it's only system audio that was half-duplex, and only on the
neo1973. the freerunner is supposed to have a nextgen codec without
the limitation.

I believe everything is connected via pcm. It would be unusual to do
it with i2s.

The main stumbling block for me was the fact that the alsa labels for
mixer controls did not match with the wolfson specs. It was too
confusing to figure out what switches to throw to get audio routed, so
I couldn't really debug the mixer settings that didn't work. That may
be different now.

There is a plan b, to route audio through the cpu (hci routing).
That's how voice bluetooth audio works on desktop machines. This burns
the battery faster and introduces delay over pcm routing. Switching to
this mode requires a reset on the bt chip, so it's not convenient
enough to choose it on a per-connection basis.

On Mon, Aug 11, 2008 at 10:41 PM, Rod Whitby <rod at whitby.id.au> wrote:
> Jim Morris wrote:
>> Without full schematics showing how the BT chip is connected to the Codec, and without the BT chips
>> docs, I cannot proceed. Depending on whether the BT chip puts out PCM or I2S it may or may not work
>> according to Wolfson, unless external circuitry has been added.
>
> Does http://downloads.openmoko.org/schematics/GTA02/ help at all?

-- 
Brad




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