An Arduino Nano is charged with running the show, capturing audio via its analog-to-digital converter. A sensitivity pot enables the input level to be set appropriately. From there, a Fast Fourier ...

Arduino notes it only supports 3.3V input and outputs (I/Os) and should not be used for connecting to 5V signals. Finally, the Nano 33 BLE Sense is available for $29.50 and comes with a range of ...