I recently repurposed an old laptop screen (from a Dell XPS L502x) as external monitor, and then made the built-in webcam work without too much fuss.
The camera module also has an embedded microphone, and I'd like to see if I can make that work as well.
I was naively expecting an analogue signal all the way to the sound card. However, the two wires for the microphone seem to be carrying a digital signal, one being DMIC-CLK1/2
and the other GPIO0 / DMIC-1/2
. They were connected to pins 46 and 2 respectively on a Realtek ALC665.
I tried figuring out whether there was any recognizable standard for this microphone's signal, but I couldn't make much sense of the docs.
So what is the communication format/standard/protocol of this microphone? Can I turn this microphone into something usable? Convert the signal back to analogue, maybe? Or will it work out of the box if I just make it a jack cable and connect it to my mic in? Would this work with another Realtek "HD Audio Codec" card only?
Here is a picture of the full webcam module:
The back displays the name of the module, "HannStar J QCM20Q-1" but no luck finding documentation online, only offers for used parts.
From left to right the main structures on the front side are:
- a big coil, L3
- a small chip, U2, with "ETF" and some dots written on it
- a partly peeled-off sticker with some product numbers
- the orifice of the microphone
- some metal cover I can't remove
- the webcam lense
- the connector (7 wires, with two mass) above some test points
- a chip with "cFeon F10-100GIP" written on it, apparently this is a memory chip.
Back and front have same top/bottom and opposite left/right, so the microphone is where "PAD L1" is on the back.
Side notes and references, in case it's useful:
My current hardware is a Realtek ALC889 sound card, in a Supermicro X9SCV-Q motherboard that seems to only have two front panel jacks for all audio connectors.
I haven't been able to find schematics for this motherboard.