https://devzone.nordicsemi.com/f/nordic-q-a/81959/osmessageget-main_msgbox-oswaitforever-with-respect-to-cpu-sleepnRF52832, SD 132, RTOS, SDK13 Can anyone let me know how CPU will do when waiting for a message like below? evt = osMessageGet(main_msgBox, osWaitForever); //wait for q box forever If CPU is running actively and waiting for a message, howen-USTelligent Community 13Tue, 23 Nov 2021 13:02:41 GMThttps://devzone.nordicsemi.com/thread/340343?ContentTypeID=1Tue, 23 Nov 2021 13:02:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:28ba47a1-0271-4a15-9199-93081b29dec9Jared<p>Hi,</p> <p>If there is nothing else to do then usually RTOS will switch over to the IDLE thread. For example in <a href="https://www.freertos.org/low-power-tickless-rtos.html">FreeRTOS </a>you can set the CPU into low power mode when it runs the IDLE thread and the IDLE hook function.&nbsp;&nbsp;</p> <p>regards</p> <p>Jared</p><div style="clear:both;"></div>