Use PCM port of M66

Hello. I have module “Quectel M66” I want to use it to transmit voice signals during calls over PCM. I used the command “AT CHFA = <4>” to switch the signal to the PCM channel, but the call over the PCM channel still failed. I wonder if Quectel M66 supports calls over PCM? Looking forward to receiving your help. Thanks!

Has anyone done and know about this problem please help me.

please use the below command to set up the PCM
for description of these command please refer the page no 48 and 49 of the attached pdf.

Also please help to share the current firmware version of the module, you can check it using ATI command.Quectel_M66_R2.0_Hardware_Design_V1.0.pdf (906.7 KB)


Thank you rahul.mahakalkar!
Let me check. If have any problems I will ask you.

hello rahul,
what type of pcm signal does m66 supports? i read the m66 hardware design document and i connected m66 module to esp32 i2s peripherals and managed to make an sinus continues alarm like beep.
but when i convert an mp3 to 16 bit raw pcm data with ffmpeg like this

ffmpeg -i input.mp3 -f s16le -acodec pcm_s16le output.raw

and then convert it to an .h file with xxd command like

xxd -r output.raw >> file.h

int_16 array and write the contents to pcm with esp32 i only get noise, what im doing wrong?

in one document i read that for ucxx series its possible to connect an external tlv320aic3104 to module and it can accept i2s input and pcm output.
so is it possible that i use this codec for m66 pcm audio?