Peripheral device: Keep advertising during connection

[CY]

Hi ,

The device required to keep advertising during the connection established.

It is human interface device which mean it is peripheral device as well.

I would like to know whether there is any sample I could take as reference for the structure.

Or it is possible to keep the keyboard_sample for development? If yes, which API or function I should integrate?

In further, I would like to know is it possible to proceed connectable advertisement.

Currently, I just understand that is possible to do non-connectable advertisement.

Thanks.

[Jimmy Wong]

HI,

I did the example (https://github.com/jimmywong2003/nrf5-bond-with-2nd-central-example).

You can find the details in the readme (LINK).

It uses 2 peripheral roles on the device.

[CY]

Hi Jimmy,

Thanks for the reply. But it seem a little be different from my requirement.

Based on your program, it seems that it is still need to interrupt the host A then start advertising again to connect with host B. It is pretty much like the multiperipheral_keyboard does.

However, the mechanism I would like to achieve is keep the advertise function during the device is still connecting with the host A.

You can imaging that it is a keyboard with beacon service.

Thanks.

[Sigurd]

Take a look at the ble_app_multiperipheral example. It will continue to advertise also after connecting to the first central.

[CY]

Hi Sigurd, 

May I know could it support connectable advertisement? I know it might interrupt the connection with first central.

So the next question is "Is it possible to connect with 2 centrals at the same time?"

(The development is based on SDK15.2)

Thanks.

[Sigurd]

CY said:

May I know could it support connectable advertisement?

 Yes, that is supported. You can have 20 concurrent connections.

CY said:

So the next question is "Is it possible to connect with 2 centrals at the same time?"

Yes, you do connectable advertising and device #1 connects. After device #1 connects, you start connectable advertising again, and device #2 connects.

[CY]

Hi Sigurd,

I have viewed the sample and found that it doesn't use peer manager.

However, the peer manager, whitelist and bond are used in keyboard sample.

Thus, I would like to know if I remove the function will it cause any effect to the HID service?

Besides that, I also found out the structure of advertising_init (on_adv_evt) and advertising_start is different from keyboard and multi-peripheral sample.

Could you give me some guide, which parts are necessary to add in the keyboard sample to support multi-peripheral sample?

Thanks.

[CY]

Is it possible to proceed the different service for each host? 

For instance, run HID service with host A and run HRS service with host B at the same time?

[Sigurd]

CY said:

Thus, I would like to know if I remove the function will it cause any effect to the HID service?

 You should keep the Peer Manager if you are developing a HID keyboard.

CY said:

Could you give me some guide, which parts are necessary to add in the keyboard sample to support multi-peripheral sample?

I don't have a guide for this, but start by setting NRF_SDH_BLE_PERIPHERAL_LINK_COUNT and NRF_SDH_BLE_TOTAL_LINK_COUNT in sdk_config.h to 2. You should then replace:

NRF_BLE_QWR_DEF(m_qwr);                                             /**< Context for the Queued Write module.*/

with

NRF_BLE_QWRS_DEF(m_qwr, NRF_SDH_BLE_TOTAL_LINK_COUNT);                          /**< Context for the Queued Write module.*/

 in qwr_init(), replace

err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init_obj);

with

    for (uint32_t i = 0; i < NRF_SDH_BLE_TOTAL_LINK_COUNT; i++)
    {
        err_code = nrf_ble_qwr_init(&m_qwr[i], &qwr_init_obj);
        APP_ERROR_CHECK(err_code);
    }

Add the ble_conn_state Connection state module, and call 

ble_conn_state_init(); in your service init code.

Add the on_connected() and on_disconnected() functions found in  ble_app_multiperipheral to your keyboard project.

CY said:

For instance, run HID service with host A and run HRS service with host B at the same time?

Yes, it's possible. But note that the service attribute table is shared, so a master/central has potentially access to both services.