https://devzone.nordicsemi.com/f/nordic-q-a/26278/nrf-51822-low-power-modeHi All, I&#39;m new to nrf51822. I&#39;m developing a battery powered device using the Nordic ble_app_uart_s110_pca10028 peripheral example program. I&#39;m glad to inform you my core program is working successfully. But now i&#39;m facing a problem, I want to implementen-USTelligent Community 13Fri, 03 Nov 2017 06:11:25 GMThttps://devzone.nordicsemi.com/thread/103434?ContentTypeID=1Fri, 03 Nov 2017 06:11:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0eadfd88-b415-43b5-9ad3-18a6af6a8cf8Sujith K Sudhakaran<p>Thank you.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/103433?ContentTypeID=1Thu, 26 Oct 2017 13:15:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5ebc62d7-ba29-4f3a-91b1-64ddcd09d2d9Sigurd<p>Hi,</p> <p>When the SoftDevice is enabled, you can use the <code>sd_power_system_off()</code> function to go to sleep(System OFF mode).</p> <p>When in System OFF mode, the device can be woken up through one of the following signals:</p> <ol> <li>The DETECT signal, optionally generated by the GPIO peripheral</li> <li>The ANADETECT signal, optionally generated by the LPCOMP module</li> <li>The SENSE signal, optionally generated by the NFC module to “wake-on-field”</li> <li>A reset</li> </ol> <p>A solution could then be to configure the pin that the switch uses as sense input(wake-up source):</p> <pre><code>nrf_gpio_cfg_sense_input(PIN NUMBER, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW); </code></pre> <p>Note that when the system wakes up from System OFF mode, it gets reset</p> <p>You can aslo find examples on how to wakeup from system on and system off mode on this <a href="https://github.com/NordicSemiconductor/nrf51-powerdown-examples">GitHub page</a>.</p><div style="clear:both;"></div>