Hello, I am working on characteristics tutorial.(our service.c) And I succeeded in notifying characteristic from nordic to android. The methods I used to notify characteristic update are timer_handler and update_characteristic. ok. that's fine. However, I don't know how nordic is aware of characteristic changed, when android sets value. How can nordic know the change in its characteristics? Is there any event handler that controls my problem? If you let me know, I guess I can finally succeed in data transfer. (While searching on Google, I found that nus_data_handler is a solution, but I think it is not fit to my example. ) Thank you.