nrf51822 password on characteristic

[Foxek]

Good evening. I write a project on nrf51822 in which there are a number of services with a set of characteristics (write and read). I need to limit access to some characteristics with a password. Is it possible?

[endnode]

You can do whatever you want on APP layer so if you define protocol on top of that Characteristic and implement some password verification the it will work. On BLE level you have only Security Manager methods which restrict access to certain (G)ATT objects as per link (encrypted/unencrypted) status but that is global for the link and GATT Server, you cannot make it more granular and define some additional PINs or passwords for each object...

[endnode]

It's higher layer so whatever you consider as "authenticated" to perform (G)ATT action which is requested by the stack that it will be. Good thing: you can do whatever you want. Bad thing: you need to be damn sure what you are doing, you are on your own.