Adding a microphone to the GBZ?

[Mewcancraft]

Hi there!

So, I've been reading up on the USB DAC situation, and I came across a schematic posted by Kilren:



I noticed though, that the usual DACs used on the forums here (Sabrent or the like) have an unused microphone jack, as can be seen in the schematic above. This got me thinking: I remember there being quite a few games for Nintendo DS which used microphone input, so ... why not integrate it into a GBZ?

Is there any reason why this hasn't been done? Am I wrong in thinking a mic could just be added by using the unused 3.5mm on the DAC?

[McGyver]

Is this feature supported by Retropie?

[Mewcancraft]

From what I've read, it used to be a sketchy topic about a year ago, though I can't find anything on what's since happened, exactly.

This github page mentions that currently, DS games requiring microphones will crash. However, let's say this gets patched in the future, or even that I'd like to use the microphone in a browser (given that it's a hypothetical multi-purpose system): would it be possible to use the aforementioned 3.5 mm connections, and how?