Write with Response request from multiple clients/mobile apps

[Minatel]

Hi all!

Is that possible to identify witch client/mobile app is associated with the write request?

Lets assume that my device can handle multiple mobile applications (on same mobile phone) writing on the same characteristics and I need to provide the proper answer to each app. To avoid getting the wrong readout I would like to synchronize the read request event with the write request for each mobile app.

Example: If app "A" writes "123456" I need to read "654321" and if app "B" writes "ABCDEF" I need to read "FEDCBA"

I need to avoid the scenario that the app "A" and "B" send write requests almost at the same time reading the wrong data, like app "A" reading "FEDCBA" instead of "654321".

I hope to be clear on my problem!

Thanks in advanced!

[Kenneth]

Hi, you should receive a BLE_GATTS_EVT_WRITE for each write, and then you can at the same time check the actual connection handle by: uint16_t conn_handle = p_ble_evt->evt.gatts_evt.conn_handle;

[Minatel]

Thanks Kenneth!

I got how to do in a different way but I still need more datils how to do that.

I need to return a error code on WRITE RESPONSE if the received data is wrong. I can manage this on READ RESPONSE but I cant on WRITE.

When I do a sd_ble_gatts_rw_authorize_reply command using status = BLE_GATT_STATUS_ATTERR_WRITE_NOT_PERMITTED; I got the error NRF_ERROR_INVALID_PARAM.

Can you give a clue on how to do that?

Thanks!

[Kenneth]

The status code looks good, have you checked that you follow the description for the api call:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v6.1.1/group___b_l_e___g_a_t_t_s___f_u_n_c_t_i_o_n_s.html#ga6de7aea3a870669e1d869b047de95545 

[Minatel]

Hi Kenneth!

I've followed this example and I got the same error message.

https://github.com/NordicSemiconductor/Nordic-Thingy52-FW/blob/master/source/ble_services/ble_uis.c

Regards,

Pedro

[Kenneth]

It seems you are looking at a decent example that show usage, so I am not sure if I have any other suggestion than to provide an example here that I can look at if you are not able to solve it. There is also this case (related to buffering, but the handling of the event may still be of use):

https://devzone.nordicsemi.com/f/nordic-q-a/35875/flow-control-over-the-bluetooth-link-central---peripherial-for-uart-example