Voice Call with MC7304

I’m trying to do a voice call and play some audio to the phone line with MC7304 minicard. The firmware version i use supports voice.

So what do I do:
Place call from modem to my phone using ATD command, this part works fine

Then trying to get some voice in my phone, or in my laptop. I suggested it could work by itself, because mc7304 should register as usb-audio device, but it doesn’t work. I hear nothing in phone or in my laptop. Ok, I would by happy to just play some audio file to my phone. I’m trying to use !AVAUDIO command, as described in documentation.

Here is the listing:

AT!AVAUDIO=1,1,some path in my pc disc

and nothing happens.

I tried with different file settings and even with wrong file path. It says OK and nothing happens. I suppose i have to use the file path not in my disc, but in memory of modem , but i don’t know how to transfer files to modem.

So what am I doing wrong? How in general we can send and get audio data in voice call?

I think you have to use audacity tool in this case. Just Google for audacity tool.

PFA the attached steps to work on audacity tool



Thanks for your help. We managed to make it work with audio.

One more question. Is USSD service supposed to work for MC7304?

We are trying to get USSD balance using *100# USSD-service.

We have tried At+CUSD command with different combination of params:


with or without double quotes for the second argument, with or without third argument.

It either says OK and we get no response message with balance, or it says and we get +CME ERROR: retry operation.

So is it supposed to work and which syntax is right for CUSD Command?

The selected attachment does not exist anymore.

try this
dropbox.com/s/aan3akxjsri51 … .docx?dl=0

Thanks, I can download it.