(TECH) How to connect microphone to GSM Breakout

What is the minimal configuration, how to connect working audio, meaning line out to amplifier and elecret microphone to the module?

I am but perplexed from RePhone Audio module and Linkit module, how to connect.

How should one connect E_INT4 and ACCDET?

Thank you

I am still fighting connecting electret microphone to GSM Breakout.

The connection partly works is following:
working_schema.png

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?

The audio will not come out unless you also have the microphone connected. It took me days and 3 earbuds to figure out. What you can do is build an electret microphone circuit powred by 3.3 volts an 1k ohm resistor.

For where the signals come out you will have to plug in a cheap earbud with bluetooth and with a scope pind the signals. Geraly with the linkit TRRS audio socket pointing to the right the third pin on the edge of the board is the audio output. The microphone is above that one and the third pin back.

you must have the plug inserted for it to work, i might be wrong . you will have to test for output if plug not in socket. i was experimenting but nothing would work then. Hope it helps some.

ljay0778