Orca
Links
frequency counter using RP2040 - https://iosoft.blog/2023/08/21/picofreq_python/
2 channel A/D (stackable) - https://community.element14.com/products/roadtest/rv/roadtest_reviews/1582/sound_measurement_an
6 channel ADC - https://www.pishop.us/product/6-channel-esp32c3-adc-hat/
Pair RPi to Android - https://bluedot.readthedocs.io/en/latest/gettingstarted.html