Frequency splithttps://devzone.nordicsemi.com/f/nordic-q-a/79122/frequency-splitHello, I have and audio source and i would need to divide it beetween two frequencies (&lt;95Hz and &gt;=95Hz). Im trying this thing with a nRF52840 and i was looking at DSP libraries, but i don&#39;t understand where to start. Do you have some advice on howen-USTelligent Community 13Thu, 02 Sep 2021 06:55:33 GMTRE: Frequency splithttps://devzone.nordicsemi.com/thread/327706?ContentTypeID=1Thu, 02 Sep 2021 06:55:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0b06d9b8-dc2b-4c50-b7b7-4facf8e6f41aGaelDeuterioIII<p>Thanks for the all the info!&nbsp;<br />I&#39;ll try what you suggested!</p><div style="clear:both;"></div>RE: Frequency splithttps://devzone.nordicsemi.com/thread/327573?ContentTypeID=1Wed, 01 Sep 2021 11:17:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d5b5d757-bc59-4a28-b579-a9a60aafba2fovrebekk<p>Hi&nbsp;</p> <p>Which SDK are you looking to use?</p> <p>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:<br /><a href="https://arm-software.github.io/CMSIS_5/DSP/html/group__groupFilters.html">https://arm-software.github.io/CMSIS_5/DSP/html/group__groupFilters.html</a></p> <p>The challenge is to generate the coefficients to use with the filters, in order to achieve the filter characteristics that you require.&nbsp;</p> <p>There is some information about this <a href="https://community.arm.com/developer/ip-products/system/b/embedded-blog/posts/an-introduction-to-digital-filtering-with-arm-microcontrollers">here</a>, just be aware they link to a tool of their own at the bottom (which you have to pay for).&nbsp;</p> <p>A colleague of mine also pointed me to a set of Python tools to do coefficient generation for FIR filters, <a href="https://docs.scipy.org/doc/scipy/reference/signal.html">here</a> and <a href="https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.firwin.html#scipy.signal.firwin">here</a>.&nbsp;</p> <p>These are free to use, but probably not as user friendly as the applications you can buy.&nbsp;</p> <p>Best regards<br />Torbjørn</p><div style="clear:both;"></div>