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I am attempting to do some real-time audio processing using the Pi Pico. I know that a MEMS microphone can be connected and used for this purpose (see here and here). However, I need to use an analog microphone that runs through an XLR cable to an ADC preamp and out into a USB format. Is connecting this to the Pi Pico possible and how could I go about this? Could I skip the preamp and connect the mic directly to the ADC pins of the Pi Pico? Or is there some expansion board that would support connecting a USB mic directly to the Pico? Bonus if you could help me understand how I2S would fit into this picture, if at all. Thanks!

fishfinder
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    You need USB host code to handle USB devices, maybe https://github.com/hathach/tinyusb. The signal level of a mic is probably too low for an ADC pin. I think you would need an analog preamp. (Some protective circuitry for your input pins is also recommended.) – Bodo Nov 21 '22 at 15:36
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    This might help: *Create a USB Microphone with the Raspberry Pi Pico* - Sandeep Mistry 2021may20 https://www.hackster.io/sandeep-mistry/create-a-usb-microphone-with-the-raspberry-pi-pico-cc9bd5 – tlfong01 Nov 22 '22 at 03:04
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    Thanks. I read through this page, but it is specifically about connecting analog and PDM mics to the Pico and transferring that data using USB, whereas I would like the Pico to itself accept a USB input. I think this is the concept of USB host referenced in the top comment. – fishfinder Nov 22 '22 at 16:19
  • Or this might help: How to use Rpi python to control *PCM1802 24-bit HiFi stereo ADC and MAX4466 microphone amplifier*, Asked 2 years, 10 months ago Modified 1 year, 8 months ago Viewed 3k times https://raspberrypi.stackexchange.com/questions/107778/how-to-use-rpi-python-to-control-pcm1802-24-bit-hifi-stereo-adc-and-max4466-micr – tlfong01 Nov 23 '22 at 06:56

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So you would need to be a USB host and support UAC2. The driver that the raspberry pi pico has is tiny USB and that currently doesn't support UAC2 in host mode. You can be a device, so you could be a mic. But there's not drivers to have a usb mic connect to the raspberry pi pico currently.

used_up_user
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