Miscellaneous questions about s110 soft device

Question

-- When a ble peripheral starts advertising and then receives a BLE_GAP_EVT_CONNECTED event, the stack stops advertising automatically right? 
 -- When you get BLE_GAP_EVT_CONNECTED and the connection parameters aren't OK (i.e. is_conn_params_ok returns false), then a timer is started. What is supposed to happen during this timer's period? It is the timeout that triggers the sending of a message to the master via sd_ble_gap_conn_param_update. Then, the master will should respond with a BLE_GAP_EVT_CONN_PARAM_UPDATE event at which point you can re-evaluate the connection parameters. I guess I don't understand what the timers are doing here. Why not just send call sd_ble_gap_conn_param_update right away without waiting?

Ole Morten · Accepted Answer

Yes, when you get connected advertising will be stopped automatically with version 6.0.0 and earlier. 
 A Central device will often do a service discovery right after connection, but if the connection interval is long, such discovery will take a long time. Often, a device will not be usable from the Central devices applications before the service discovery is finished. Hence, to make sure the discovery finishes as soon as possible, and that the Peripheral becomes usable as fast as possible, it's often desirable to keep a short connection interval for the service discovery and then only request a longer interval afterwards. There is no way to get an event when service discovery is finished, so instead we just use a timer to delay the request for some time, which should be sufficient. If it is too long, the only downside is that the average current consumption will go up marginally. 
 For details on the connection parameter update procedure, I'd actually recommend you to take a look at the Bluetooth specification . It's described in Volume 3, Part C, Section 9.3.9.