How to use 3,5mm 3-pol Microphone-connectors?

Hi guys,

after successfully installing my cirrus audio logic card on my Rasp. Pi 2, I' m now trying to connect one of my old microphones with a 3,5 mm 3-pol-connector to the sound card. Is it even possible?

I know the sound card has onboard microphones - they are working, but I need to use a wired microphone for my project. I already tried smartphone-headset on the 4-pol headset plugin (black). The headset-microphone worked, but is very very very very quit.

I now tried to use one of my old 3,5 mm 3-pol wired microphones in the lineIN (pink plugin). But I am not able to get a signal.

I thing I missed some information - but the cirrus dokumentation of the sound card wasn't able to solve my problem. The whole 3- and 4-pol thing is very confusing.......

spambake over 9 years ago

Unfortunately information for the Cirrus card is scattered all over the place. Did you try the Record_from_lineIn_Micbias.sh script? It provides a bias to power the microphone and boosts the signal to a better level. You can change the various volume levels in the scripts to suit.

To make full use of the line in port you would probably need to solder up your own plug. The Cirrus schematic shows the configuration for the various ports.

For the Line In:
Tip = Left
Ring = Right
Sleeve = Ground

The four pole headset port uses the CTIA/AJH standard.
Starting at the tip:
Tip = Left
Ring = Right
Ring = Ground
Sleeve = Mic
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Former Member over 9 years ago in reply to spambake

yea I tryed it - didn't worked

I think my next try will be to solder on the 4-pol headset connector
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spambake over 9 years ago in reply to Former Member

The various cheap electret microphone capsules seem to work well. A couple of us are using the Panasonic WM-61a clones, but most any should do just fine. Just use shielded cable and follow the polarity.
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Former Member over 9 years ago in reply to spambake

and do you use them with the headset or line-in connection?
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Former Member over 9 years ago in reply to Former Member

okay ...guess what ...i didn't pushed the 3,5 mm 3pol hard enough in the line in....
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