How to Interface MEMS Microphone to BlueNRG-2..? Is it Either Using IO pints or ADC.? Can anybody share the reference?

[RN.304]

I need to connect Microphone to BlueNRG-2 and How Can I interface with the Chip.?

[Eleon BORLINI]

​hi, it depends on the microphone you are using. If the mic is analog (differential or single ended like MP23ABS1), you have to interface it to ADC pins (ADC1 and ADC2 --> OUTP and OUTN). If the mic is digital (e.g. MP34DT05-A) you can directly connect it to PDM interface (IO1x and IO2x pins --> CLK and DATA)

Because of it's a 10bit ADC, if you are interest to a good SNR I suggest you to use a digital microphone.

Regards

[RN.304]

Dear Eleon,

Thanks for the input and yes I am using digital MIC. so I can connect directly to any IOx pin which has PDM functionality as per the GPIO table right.?

[Eleon BORLINI]

​yes, you're right. You can use IO pins in Serial2 mode that support PDM (up to 2 mics per line, if working in stereo mode). Regards

[RN.304]

Thanks for the Input Eleon.

[RN.304]

Hi Eleon,

High speed clock can be 16MHz or 32MHz which one would you recommend..? form the EVM i can see they have used 32MHz and any recommended crystal Part for the same.

Thanks

Rajesh.

[Eleon BORLINI]

hi Rajesh, if you want to use the internal clock, you are limited to the internal high-speed ring oscillator 16MHz, but I agree with you to use the external 32MHz clock.