Cellular radio module voice call


I bought cellular radio module, I connected a microphone into the “mic” and the headphones into the “speaker”, making a voice call, you will hear the voice of the receiver but he did not hear me, I tried to change the microphone but not heard.
Is the card defective?


I do not think anyone tested this feature in this forum. I would check the schematics and check with seeed, the company who made this module.

I connected Audio out from the audio module and played some wav files over the cellular module… Sound came trough to my phone. Maybe it don’t have mic amp on board…try playing audio from an MP3 player or something like that, connect headset jack from MP3 player to mic input on cellular module. You should be able to hear audio then (we did).

I also tried to connect “music module” speaker to “cellular module” mic and in the phone can not hear anything.

you hear voice in the headphones, but not in the phone receiver.
voice of phone receiver is heard in the headphones.

SMS work fine, sending and receiving.

Today I received the card in place of the defective one and the new one works fine.

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@ luca_santoro - Good to hear that we were able to resolve your issue, thanks for the update!