Before I dig into sending data over BLE I want to confirm a few things.

Am I correct to assume writing to Serial1 sends data over Bluetooth, and Serial1.Read() will read any incoming bluetooth bytes?

What methods are there to confirm a connection is made, or disconnect occurred?

As much as I've done Bluetooth stuff on arduino boards, I've never seen any indications in code which tell whether a device is connecting or disconnecting.

I could be wrong in CBT case tho, but something tells the serial will not get any events by default from BLE chip.

tho let's wait for someone, who knows more about Arduino stuff, to answer.