BLE connection create parameters and connection parameters questions

[PingISTL]

Dear support

I am developing a generic central application intended to connect any BLE devices which is connectable. So I need to figure out which parameters are needed and make the them configurable. In Central multilink sample, there are two sets of parameters shown below:

	struct bt_conn_le_create_param create_param = {
		.options = BT_CONN_LE_OPT_NONE,
		.interval = INIT_INTERVAL,
		.window = INIT_WINDOW,
		.interval_coded = 0,
		.window_coded = 0,
		.timeout = 0,
	};
	struct bt_le_conn_param conn_param = {
		.interval_min = CONN_INTERVAL,
		.interval_max = CONN_INTERVAL,
		.latency = CONN_LATENCY,
		.timeout = CONN_TIMEOUT,
	};

The first one is create_param, and second one is conn_param, I read some explanation about the conn_param, but never find anything on create_param, could someone explain to me please? is INIT_INTERVAL and INIT_WINDOW important to make connection? shall I make it changeable by user?

Thank you.

Ping

[Menon]

Both conn_param and create_param are BLE connection parameters. You can find both here. create_param is just Initializing the parameters for the connection .You can establish a connection without this function

About the parameters in the function create_param,

interval: how long to wait between each scan, i.e after a scan is over and before the next scan starts.

window: How long the scan should be for.

timeout: This timeout determines the timeout from the last data exchange till a link is considered lost.

And both interval_coded and window_coded works the same as interval and window but for long range connection. You can use the default values as shown here. An if you check the sample central_multilink you can see INIT_INTERVAL and INIT_WINDOW are the values set in the specific applications. 

Kind Regards,

Abhijith