Multilink example code

RE: Multilink example code

Edvin — Wed, 08 May 2019 13:06:09 GMT

Ok. I see.

Depending on what service you have, it is the service handler of that service. In an unmodified ble_app_multilink_central, which uses the lbs (led button service), this would be the lbs_c_evt_handler() in main.c.

An event will be triggered when one of the connected boards pushes a button. This event is BLE_LBS_C_EVT_BUTTON_NOTIFICATION.

Note that it is the same event for all devices, but you can see in the message that is printed in the log:

NRF_LOG_INFO("Link 0x%x, Button state changed on peer to 0x%x",
            p_lbs_c_evt->conn_handle,
            p_lbs_c_evt->params.button.button_state);

So a message could be: "Link 0x2, Button state changed on peer to 0x1", which means that the device with connection handle 2 pressed the button.

So you use the connection handle, conn_handle, to determine which device that sent the message, and depending on what characteristic you have, the data will be found in that characteristic.

RE: Multilink example code

Rekha — Wed, 08 May 2019 10:40:00 GMT

Hi Edvin,

Sorry if my question was not clear.

[quote userid="26071" url="~/f/nordic-q-a/45324/multilink-example-code/185914"]Do you mean where you can see if any of the devices that are connected sends a message,[/quote]

Yes i meant this.

Thanks

RE: Multilink example code

Edvin — Wed, 08 May 2019 10:36:23 GMT

What do you mean by "being tracked"? Do you mean where you can see if any of the devices that are connected sends a message, or how you can send messages to a specific device? How you connect to the devices, or how to know when the devices are disconnected?

Basically, the SoftDevice (BLE stack) handles all of the connections, so you will not notice anything, unless something happens, such as a connection event, disconnection event, or if someone sends a message.

RE: Multilink example code

Rekha — Wed, 08 May 2019 09:52:18 GMT

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

RE: Multilink example code

Edvin — Wed, 08 May 2019 08:39:42 GMT

[quote user="Rekha"]How does the links(connections) are tracked in multilink example code?[/quote]

What do you mean?

RE: Multilink example code

Rekha — Tue, 07 May 2019 11:58:56 GMT

Thank you for the details.

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

Thanks

RE: Multilink example code

Edvin — Tue, 07 May 2019 07:57:05 GMT

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.

RE: Multilink example code

Rekha — Tue, 07 May 2019 07:16:08 GMT

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

RE: Multilink example code

Edvin — Tue, 07 May 2019 07:04:58 GMT

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
}

RE: Multilink example code

Rekha — Tue, 07 May 2019 06:23:11 GMT

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

RE: Multilink example code

Rekha — Tue, 07 May 2019 06:20:52 GMT

Thank you i followed example code to implement discovery module.

RE: Multilink example code

Edvin — Thu, 28 Mar 2019 13:32:48 GMT

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

RE: Multilink example code

Rekha — Thu, 28 Mar 2019 09:17:26 GMT

[quote userid="26071" url="~/f/nordic-q-a/45324/multilink-example-code/178117"]BLE_DB_DISCOVERY_DEF [/quote]

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

RE: Multilink example code

Edvin — Mon, 25 Mar 2019 13:23:13 GMT

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