Idea: Audio-in and audio-out on same connector

[Ole Tange]

It has been discussed on the list that it might be useful to have
connector for line-in. So far I have found that the price would be too
high, as the device will then have to have yet another connector. But
then I wondered: Would it be possible to use the same physical
connector?

I have never seen a device where the same connector could act as both
audio-in and audio-out, but my logic says that it should be possible
in theory: When in audio-out mode the line will be controlled by a ADC
and when in audio-in mode it will be controlled by a DAC. It would
rarely make sense to have the ADC and the DAC be active at the same
time.

Is there a physical limitation I am not aware of?

/Ole
-- 
http://www.linuxtogo.org/gowiki/OpenMoko/ideas/AudioInAudioOutOn1Connector