Not able to receive data from built-in microphone on ArduCAM Pico4ML-BLE

Question/Issue: Not able to receive data from built-in microphone on ArduCAM Pico4ML-BLE

Project ID: 298644

**Context/Use case: I am trying to measure the flow rate of water using sound with the ArduCAM Pico4ML-BLE but when using the uf2 file deployed for RP2040, the built-in microphone doesn’t seem to work.

I have also tried to use the Data Forwarder but I get the error “Failed to get information off device No valid sensor readings received from device. Note that the data forwarder can only auto-detect frequencies >2Hz. You can override the frequency via --frequency.”

I am now trying to deploy as a C++ library but can’t wrap my head around how I could get the raw features from the microphone.**

Hi @william.chen,

Please see this note about the ArduCam Pico4ML board: https://docs.edgeimpulse.com/docs/development-platforms/officially-supported-mcu-targets/raspberry-pi-rp2040#using-with-other-rp2040-boards. Specifically, the microphone on that board is not supported by the official Edge Impulse firmware. You will need to use the Arduino RP2040 Connect if you wish to use the microphone driver built by Edge Impulse, or you will need to write your own microphone driver.