https://devzone.nordicsemi.com/f/nordic-q-a/68050/how-to-enter-into-deep-sleep-modeHi, I have interfaced the nRF52832 with temperature sensor via i2c(MAX30205 temperature sensor) . I am advertising only when it become low temperature( setting the threshold ) using ble_app_beacon 1. To check the threshold i am using time, every oneen-USTelligent Community 13Fri, 06 Nov 2020 10:04:59 GMThttps://devzone.nordicsemi.com/thread/278744?ContentTypeID=1Fri, 06 Nov 2020 10:04:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2245854d-c9a2-4b46-97e1-62f6ac78bb6dEdvin<p>Hello,</p> <p>The sensor is an I2C sensor? so it will output a signal (actively) when the threshold is reached? Or do you need to trigger the read from the nRF?</p> <p>If you need to trigger this, and you trigger it from a timer interrupt, you need to use system on sleep, because the timer&#39;s can&#39;t run in system off mode.&nbsp;</p> <p>If it gives an interrupt on it&#39;s own, you can go to system off mode, and enable one of the pins (the sda pin, for example) as a wakeup pin.</p> <p></p> <p>Best regards,</p> <p>Edvin</p><div style="clear:both;"></div>