Write Characteristic only when Paired

[Joao Dullius]

NCS 2.1.0 / nRF52840-DK

Hello,

I have a single write characteristic on my service:

BT_GATT_SERVICE_DEFINE( custom_srv,

                        BT_GATT_PRIMARY_SERVICE(BT_UUID_CUSTOM_SERVICE),

                        BT_GATT_CHARACTERISTIC( BT_UUID_ADV_PERIOD_CHRC,

                                                BT_GATT_CHRC_WRITE_WITHOUT_RESP,

                                                BT_GATT_PERM_WRITE,

                                                NULL, on_write, NULL),

                        );

How do I set that this characteristic can be only written if there is an active pairing with the device?

In other words, I want user to only be able to write characteristic if security level is 3 or above.

[Joao Dullius]

Got it. I was able to achieve the required behavior by changing from BT_GATT_PERM_WRITE to BT_GATT_PERM_WRITE_AUTHEN.

Follow-up question:

- Can I make a characteristic only visible to paired devices?