How to prevent ble_app_UART that implements pairing from connecting to ble_app_uart_c that does not implement pairing

[morita]

Module: nRF52832

Implemented pairing for ble_app_UART (NUS).
However, I can connect with ble_app_uart_c, which does not have pairing implemented.
Please tell me how to prevent the ble_app_UART that implements pairing from being connected to ble_app_uart_c that does not implement pairing.

[Einar Thorsrud]

Hi,

Bonding/pairing is a step that happens after connection, and there is no way to know beforehand if the peer supports bonding/pairing or not. The best you can do is probably to try to pair/bond early, and disconnect immediately if that is not an option. You should of corse also ensure that the security parameters of the characteristics that you want to protect are such that they cannot be accessed without pairing/bonding.

[morita]

Thank you for your answer.
Sorry for the late reply.
What I want to do is only allow connections to the ble_app_uart_c that is paired.
If it is ble_app_uart_c that implements pairing, it will not be connected if it is not paired.
s there only a way to disconnect after connecting?

[Einar Thorsrud]

Hi,

Aha, so you have an existing bond, and only want to allow the bonded device to connect? If so, that is very standard, and the concept of whitelisting in Bluetooth is for this exact use case. Then you start advertising with a whitelist which only includes the bonded peer, and only that will be allowed to connect. Any other connection attempts will be ignored by the Bluetooth stack.

You can refer to for instance the ANCS example to see how whitelisting is used.

[morita]

Thank you very much.
Problem solved.