I have a basic question regarding a basic area. Interrupts! But without any good specification and how the OS work and good example how to do this I need to push for the obvious. So if you use an BLE stack and want to subscribe for an IO interrupt where you can registered a hook to be called when the interrupt occur, How do you do it? I have looked at GPIOTE, APP_GPIOTE, NRF_GPIO, APP_BUTTON but I never get any event even if the IO change level. I do not want to use any polled system or use any tick or timers. Pure INT as it should be used. Any advice!