BLE nrf52832 SDK11 characteristic update with every read operation

[anuja]

I am using Nrf52832 sdk 11.I want to update the value of characteristic on every read operation from my andriod phone. I want that on every ble_gatts_evt_read: should give me new value whatever i feed through code. How should i implement ble_gatts_read to update the characteristic value with passkey implemented.

[endnode]

Sorry but that doesn't make sense. GATT Read (not Read Request) doesn't invoke any event on GATT Server side so the serve doesn't know you read the value and so it hardly can determine when to change it internally. Use Read Request or Write/Notify architecture.

[Petter Myhre]

Sounds like read request with authorization is what you are looking for, see this MSC.

You need to enable authorization for the characteristic value. See this.

[anuja]

Thanks peter but for this MSC which data structure should be implemented.will ble_gatss_rw_authorize_request work? so that on every read of characteristic the value should be updated.?

[Petter Myhre]

If you set ble_attr_md.rd_auth = 1; for the characteristic value that you want to support authorization, you should get a BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST event every time it is read. Then you have to reply to the event with sd_ble_gatts_rw_authorize_reply().