[NUC505] Fast Fourier Transform Using M4 DSP

[chhsieh3]

• Application: This sample code uses FFT to get main frequency from Line-in.
• BSP Version: NUC505 Series BSP CMSIS V3.02.000
• Hardware: NuTiny-EVB-NUC505 V1.6

This sample code uses NUC505 internal codec and gets audio data from LINE IN. Use CMSIS DSP library to do Fourier analysis. Users can hear the sound from LINE IN by connecting the headphones. In the sample code, only the right channel audio is analyzed, the sampling frequency is 8000 Hz, and the data length is 16 bits. The number of samples for FFT is 1024. Decreasing the number of samples reduces the computation time, but the resolution is worse. The user can set the volume threshold according to the VolTH parameter.

You can download the sample code at https://www.nuvoton.com/resource-downlo ... 1102163850