https://devzone.nordicsemi.com/f/nordic-q-a/37830/wakeup-from-sleep-with-gpio-not-resetI would like to put a nrf51822 device into system sleep (not off) mode and wake it up (not reset) with a GPIO transition from high to low. I used SDK(nRF5_SDK_12.2.0_f012efa) and the project： nRF5_SDK_12.2.0_f012efa\examples\ble_peripheral\ble_app_uarten-USTelligent Community 13Tue, 28 Aug 2018 12:49:23 GMThttps://devzone.nordicsemi.com/thread/146117?ContentTypeID=1Tue, 28 Aug 2018 12:49:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:478d9835-10b2-4140-8fe2-9d5f7b3ef8c5Bj&#248;rn Kvaale<p>Do you want to put the system in system on low power mode (see the nrf51822 <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf51/dita/nrf51/pdflinks/51822_ps.html?cp=3_4_0">product specification</a> doc for more info)?</p> <p><a href="https://devzone.nordicsemi.com/f/nordic-q-a/36475/nrf52832-go-system-off-low-power-mode-and-wakeup-by-gpio">This devzone case</a> should also be helpful, even though it is based on the 52832 &amp; not the 51822 (much of the power management has remained the same). The ble_app_uart code already calls power_manage() inside the main function, which calls <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s130.api.v2.0.1/group___n_r_f___s_o_c___f_u_n_c_t_i_o_n_s.html?cp=3_7_2_1_0_2_7_2_0#ga11d88d38ac99fb72cde74c9385d36433">sd_app_evt_wait()</a>. sd_app_evt_wait() puts the nrf51 into system on low power mode. You can then wake the chip using GPIOTE interrupts. <a href="https://devzone.nordicsemi.com/f/nordic-q-a/17333/nrf51822--gpiote-interrupt-for-wakeup-with-softdevice">This case</a> might also be helpful.</p><div style="clear:both;"></div>