nRF52832 clock frequency keeps changing randomlyhttps://devzone.nordicsemi.com/f/nordic-q-a/64692/nrf52832-clock-frequency-keeps-changing-randomlyI&#39;ve got an application that reads MP3 files from an SD card, decodes them and outputs audio data to a codec via I2S. The codec is clocked by MCLK generated by the nRF. The boards do not have a 32768 Hz crystal. The 32 MHz crystal is present. NRF_SDH_CLOCK_LF_SRCen-USTelligent Community 13Tue, 11 Aug 2020 09:25:44 GMTRE: nRF52832 clock frequency keeps changing randomlyhttps://devzone.nordicsemi.com/thread/263982?ContentTypeID=1Tue, 11 Aug 2020 09:25:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cdac3715-58ec-4565-9f4d-e6baa82b8dcfhaakonsh<p>You can always turn the HFXO (crystal) off whenever you don&#39;t need it.&nbsp;</p><div style="clear:both;"></div>RE: nRF52832 clock frequency keeps changing randomlyhttps://devzone.nordicsemi.com/thread/263961?ContentTypeID=1Tue, 11 Aug 2020 08:44:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:38cfdcf1-e6fd-4b4a-b720-d9b792580e9aTurbo J<p>The NRF Bluetooth chips switch from HFINT to HFCLK (crystal) and back automatically.</p> <p>When using softdevice, you can keep the HFCLK running by</p> <p><pre class="ui-code" data-mode="c_cpp">sd_clock_hfclk_request();</pre></p> <p>It will consume a bit more power, but you need the HF clock running anyway for UART and I&sup2;S.</p><div style="clear:both;"></div>