https://devzone.nordicsemi.com/f/nordic-q-a/116269/ncs2-6-1-idle-threadThe CPU runs the main thread every 3 seconds, and for the remaining time, it enters the idle thread. However, after entering the idle thread, it doesn’t save power. But if I directly call the function shown in the image, it can enter power-saving modeen-USTelligent Community 13Tue, 12 Nov 2024 10:21:00 GMThttps://devzone.nordicsemi.com/thread/510065?ContentTypeID=1Tue, 12 Nov 2024 10:21:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f3c08a81-8647-49f2-85f4-1727bf6a881eKenneth<p>If you need the accuracy of the high frequency crystal, then the application need to start&nbsp;the hfclk when the accuracy is needed, and then stop it when it&#39;s no longer needed.</p> <p>Kenneth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/510037?ContentTypeID=1Tue, 12 Nov 2024 08:21:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7d0f022d-ef51-4a57-b6a1-6b2c23c3487calbert<p>sorry , because I enabled the high-frequency crystal oscillator at startup</p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1731399567068v1.png" alt=" " /></p> <p>Do I need to manually enable the high-frequency crystal oscillator, or can it automatically turn on when needed, such as during UART transmission and reception?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/509850?ContentTypeID=1Mon, 11 Nov 2024 10:53:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ec7a4f02-e764-41e7-9f46-5f0b5ce27706Kenneth<p>Check out:&nbsp;<br /><a href="https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/test_and_optimize/optimizing/power_general.html">https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/test_and_optimize/optimizing/power_general.html</a>&nbsp;</p> <p>If you still have problems, would be nice if you can specify you what measure, this may give some indication of the problem. Make sure to power cycle the board before measuring current.</p> <p>Kenneth</p><div style="clear:both;"></div>