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Visitor II
March 15, 2019
Question

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

  • March 15, 2019
  • 2 replies
  • 1304 views

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

    This topic has been closed for replies.

    2 replies

    ST Employee
    March 15, 2019

    ​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

    0690X00000881P5QAI.png

    RN.304Author
    Visitor II
    March 15, 2019

    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.?

    ST Employee
    March 15, 2019

    ​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.304Author
    Visitor II
    March 15, 2019

    Thanks for the Input Eleon.

    RN.304Author
    Visitor II
    March 18, 2019

    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.