How can I make only bonded devices can write to my characteristic on nRF_5 chip?

[Mustafa]

I am developing an application with a single service that has a single characteristic with read and write operations.

I want to give the ability to writing to this characteristic to only bonded devices and not just any connected device.

I tried "signed write" option, but I couldn't write neither with a bonded device nor with a non-bonded device.

I know that this feature is possible in BLE, however, I can't implement it. Please, enlighten me.Thanks.

Note: I am using PCA 10028, sdk 12.2.0, s130 v 2.0.1, and I am using the default security settings in my project (following ble_app_tempelate example).

[Jørgen Kvalvaag]

Take a look at one of the BLE examples that utilize this behaviour. Eg in the ble_app_gls example:

If you look at the function record_access_control_point_char_add in ble_gls.c it is using the macro BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM() on attr_md.write field. Now only peers on encrypted links are allowed to write to this characteristic value.

[Mustafa]

Thank you for the great info.