Couldn't occur the BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST event

[Alice]

Hi,

I'm using the nRF5_SDK_12.0.0_12f24da and S132 on nRF52832. I do the multilink based on the ble_app_multilink_central example. When it has connected to the peripheral,the peripheral will send a connection parameter update request to the center. I have set a breakpoint at BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST event ,but the center wouldn't run to the BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST event , so the center couldn't update the connection parameter. Is there anyother thins I need to do?

It's sure that the peripheral has send a connection parameter update request to the center.

[run_ar]

Are you sure you actually sent a connection parameter update request from the peripheral? Can you check with a sniffer to see what is happening?

[Alice]

Yes, I'm sure. But it's ok now. I have changed the connection timeout to 5s, if I don't use 5 second as the connection timeout, it's ok. I try 3s,4s and 6s and so on, it's ok. But I donn't know why.

[run_ar]

If you look at conn_params_negotiate on the peripheral you can see that not all parameters are checked. And that we won't send a conn param update request if the parameters is within the max/min settings (see is_conn_params_ok).

The multilink central will call sd_ble_gap_conn_param_update on any ble_gap_evt_conn_param_update_request (see on_ble_central_evt)

So changing the connection timeout won't trigger a update, but if you change the max/min values on the peripheral it will (or you need to modify the test in is_conn_params_ok to also check the timeout value).