How to give response after app read characteristics

[mo]

Hi The problem is that when app read one of my characteristics I want to realize which characteristic is read with an event?

[endnode]

You should get GATTS (GATT Server) event and in event data you should see which (G)ATT handle was targeted. Or do you encounter some specific problem during this flow?

[bjorn-spockeli]

You will not get an event when a peer reads a characteristic unless you require read authorization(this is set when you add the characteristic). You should then get the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST event.