Multilink example code

[Rekha]

Hi  i am using SDK15.2, nrf52832 board.

Which function is necessary to achieve multilink in example code. I dont understand how the central is connecting multiple peripherals at the same?

Please provide me some more details because i have the similar requirement to connect multiple peripherals at the same time.

Thanks,

Rekha

[Edvin]

Hello,

There is no single function that is used for this, but I suggest you check out the ble_app_multilink_central example found in:

SDK15.2.0\examples\ble_central\ble_app_multilink_central.

A few keywords that you should check out are:

NRF_SDH_BLE_CENTRAL_LINK_COUNT

BLE_DB_DISCOVERY_ARRAY_DEF (compared to BLE_DB_DISCOVERY_DEF in the non-multilink examples). 

Also note that you have the BLE_LBS_C_ARRAY_DEF. This will apply to any services that you use. You need to use an array instance instead of a single instance, to keep track of all the devices you are connected to.

Best regards,

Edvin

[Rekha]

Edvin said:

BLE_DB_DISCOVERY_DEF

Do i need to connect the devices first to make this ble_dbz-discovery function work? 

[Edvin]

Yes, you do.

I suggest that you start with the ble_app_multilink_central example, and switch the services lbs_c to whatever services you intend to use.

BR,

Edvin

[Rekha]

Thank you i followed example code to implement discovery module.

[Rekha]

But i still have my previous question unanswered.

I have array of MAC address to connect. which is the best way to connect all devices at the same time?

Thank you

Rekha 

[Edvin]

continue to scan even if you are connected to a device. 

Please look at how this is done in ble_app_multilink_central in ble_evt_handler -> BLE_GAP_EVT_CONNECTED.

if (ble_conn_state_central_conn_count() == NRF_SDH_BLE_CENTRAL_LINK_COUNT) // Connected to all devices
{
    bsp_board_led_off(CENTRAL_SCANNING_LED);    // all devices connected. Don't scan
}
else    //Not all devices connected. Restart scanning.
{
    bsp_board_led_on(CENTRAL_SCANNING_LED);
    scan_start(); //<-- Here. Start scan
}

[Rekha]

Hi 

After scan operation i have stored set of devices to connect.

currently scan will be stopped and i start connecting the MAC address which i already have with me.

Thanks

[Edvin]

Is that a question?

Yes. The scan will be stopped when you connect. If you want to connect to more devices after connecting to a device, you must start scanning again, as I tried to explain in my previous reply.

[Rekha]

Thank you for the details.

How does the links(connections) are tracked in multilink example code?

 Thanks

[Edvin]

Rekha said:

How does the links(connections) are tracked in multilink example code?

 What do you mean?

[Rekha]

since this example code is suggested for multiple connections, where are these multiple connections are being tracked in the code.