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AIROC™ Bluetooth Forum Discussions

HTerm1
Employee
Employee
5 sign-ins First like given First reply posted

Hi there,

I'm trying use a external microphone with my CYW208xx (CYW920819EVB-02) . The output of the mic is a PDM signal. Now I set the GPIO  to PDM_IN 0  and connected the data line from the mic. My question now is:

Is there any documentation on how to use the PDM interface with Modus Toolbox? I would like to know the following things.

  • What functions do I use to start the "recording" ? 
  • How do I change the sampling rate ?
  • How can I output the filtered samples ?

"The CYW208xx accepts a ΣΔ-based one-bit pulse density modulation (PDM) input stream and outputs filtered samples at either 8 kHz or 16 kHz sampling rates."

(I found the wiced_bt_audio_record.c and pdm_aud_record.c but both include wiced_bt_audio_record.h which i can not find. )

thank you in advance !

1 Solution
AnjanaM_61
Moderator
Moderator
Moderator
First comment on KBA 5 questions asked First question asked

Hi @HTerm1 

Our Bluetooth chips supports only I2S / PCM interface to use A2DP/HFP profiles for audio streaming. 

Regards,
Anjana

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3 Replies
AnjanaM_61
Moderator
Moderator
Moderator
First comment on KBA 5 questions asked First question asked

Hello @HTerm1 

We do not have PDM library support for 208xx devices. 

Please refer to the Technical brief doc for supported &  unsupported features & example codes. 

https://community.infineon.com/t5/Resource-Library/AIROC-Bluetooth-SDK-3-2-Technical-Brief/ta-p/3319...

Regards,
Anjana

HTerm1
Employee
Employee
5 sign-ins First like given First reply posted

Thank you for your reply !

I'm trying to implement a Bluetooth microphone.  I'd like to use a external digital microphone (output PDM) combine it with a MCU+ Bluetooth chip and send/stream the recording to a smartphone, so I can listen to the recorded sound.

Which chip would you recommend for such a audio application?

Thank you in advance, BR

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AnjanaM_61
Moderator
Moderator
Moderator
First comment on KBA 5 questions asked First question asked

Hi @HTerm1 

Our Bluetooth chips supports only I2S / PCM interface to use A2DP/HFP profiles for audio streaming. 

Regards,
Anjana

0 Likes