# connecting speaker and mic to GSM SIM 900

I have a gsm module but unfortunately it doesnt have an output for mic and speakers. I need to integrate mic and speaker too. In my GSM module, there are male pins available for mic_P mic_N for microphone and spk_P spk_N but I dont know how to connect these to speakers and microphone. Does anyone have any idea about this? Please share.

I am attaching a pic of my gsm module:

• Quite often you can just connect MIC_P to the positive side of an electret microphone and MIC_N to the negative. Likewise with a small speaker or set of headphones. The module won't drive a large speaker. Check if there is a voltage across MIC_P and MIC_N. – pjc50 Jul 28 '15 at 17:44
• @pjc50 electret microphone... is it the normal microphone or something else? – anna carolina Jul 28 '15 at 17:46
• It's .. an electret microphone. It should be in the description in a parts catalog. – pjc50 Jul 28 '15 at 17:49

You can use electret microphone. Connect its positive to MICP & negative to MIC_N.
Alternatively, for testing purpose you can also use your headphone. Cut the headphone wire and you will find wires to connect with SPK_P SPK_N MIC_p MIC_N .