Frequency split

[GaelDeuterioIII]

Hello, 
I have and audio source and i would need to divide it beetween two frequencies (<95Hz and >=95Hz).

Im trying this thing with a nRF52840 and i was looking at DSP libraries, but i don't understand where to start.
Do you have some advice on how i could achieve such task???
Thanks!

[ovrebekk]

Hi 

Which SDK are you looking to use?

The ARM CMSIS libraries include functions for running FIR and IIR filters, which allows you to do things such as high pass and low pass filters:
https://arm-software.github.io/CMSIS_5/DSP/html/group__groupFilters.html

The challenge is to generate the coefficients to use with the filters, in order to achieve the filter characteristics that you require. 

There is some information about this here, just be aware they link to a tool of their own at the bottom (which you have to pay for). 

A colleague of mine also pointed me to a set of Python tools to do coefficient generation for FIR filters, here and here. 

These are free to use, but probably not as user friendly as the applications you can buy. 

Best regards
Torbjørn

[GaelDeuterioIII]

Thanks for the all the info! 
I'll try what you suggested!