https://devzone.nordicsemi.com/f/nordic-q-a/20763/can-i-put-my-nrf51822-in-sleep-modehai in my application i am using nrf51822 . i have connected some sensors with the mcu. and i am collecting values from the sensors and this values are updated to the service data in every seconds. so can i put my nrf51822 into sleep between each updatingen-USTelligent Community 13Fri, 24 Mar 2017 08:09:49 GMThttps://devzone.nordicsemi.com/thread/81069?ContentTypeID=1Fri, 24 Mar 2017 08:09:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:00795d9f-2718-469c-8539-721490b2721dJ&#248;rgen Holmefjord<p>Hi,</p> <p>There are two sleep modes in the nRF51822; <a href="http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.1.pdf#page=44">System OFF and System ON mode</a>. System OFF mode is the deepest sleep mode, requiring a reset, GPIO signal or LPCOMP signal to wakeup. You can put the device into this mode by setting <code>NRF_POWER-&gt;SYSTEMOFF = 1;</code> if not using a softdevice, or by calling <code>sd_power_system_off()</code> if a softdevice is used.</p> <p>System ON mode will wake up on any event from periherals, like RTC, timer, radio etc. You can enter system ON mode by calling <code>__WFE()</code> if not using softdevice, or <code>sd_app_evt_wait()</code> if softdevice is used.</p> <p>If you look in the examples in the SDK, most of them have a endless loop in main calling <code>__WFE()</code> or <code>sd_app_evt_wait()</code> to put the chip in sleep mode as soon as other tasks are done.</p> <p>Best regards,</p> <p>Jørgen</p><div style="clear:both;"></div>