I am still fighting connecting electret microphone to GSM Breakout.
The connection partly works is following:
This works only when AU_VIN0_N connected between R1 and R2 (strange), not working when connected with 1k to MICBIAS0 only.
I looked to the Audio module, but there is AU_VIN0_N connected to the GND, and this configuration does not work for me. There is strange electret microphone with 3 outputs (I have only 2).
I looked also to LintIt Assist 2502A schema, where MIC is connected to AU_VIN0_{N,P} with 2.5k resistors to MICBIAS0 and GND and this circuit did not work for me either.
What would be the correct wiring?