Bluetooth Setting Changes when mainly using app core

[Paul M.]

Hello,

I am using the nrf5340. My project is quite large but running on the app core just fine.

Now, I have the problem that I want to adjust some BLE settings, like tx Power, connection intervall ecc. As I have read here, it is said that bluetooth is generally handled using the net core.

I cannot build my project on the netcore however since it is to large and needs a lot of periphery which is not trivial to access using the net core apparently. Also, I have not found a easy example or documentation on how to send data from the app to the net core (I thought of doing so, so I have all the periphery communication and processing on the app core, send the data to the net core and have the netcore transmit the data via ble).

My question now is: would that really be the best process to do so? My basic example on which I started building my project was the peripheral uart example, which does not seem to use the net core for bluetooth at all.

Thanks in advance,

Morandell Paul

[Paul M.]

I have some further issues implementig the CONFIG_BT_CTLR_TX_PWR_ANTENNA or gernerally the 

BT_CTLR_TX_PWR configs, it says that it needs the BT_CTLR dependency, however, if I introduce CONFIG_BT_CTLR into my prj.cong I get building errors. I now just removed the BT_CTLR depency in the Kconfig file. It now still requests the choice BT_CTLR_TX_PWR dependency. How can i select such a choice in the prj.conf?

[Einar Thorsrud]

Hi,

The dependencies is that the controller must be the SoftDevice controller (i.e. not the Zephyr controller which is what you get with BT_LL_SW_SPLIT). This is the default so you don't need to think about that. If you started with a Bluetooth sample, you just need to add that specific config. If you have done other changes try reverting them.

[Paul M.]

After doing that, I do not get any further warning regarding the dependencies. However, the tx power does still not change. It is always the power I put into default. Meaning, if I remove the BT_CTLR dependency and call CONFIG_BT_CTLR_TX_PWR_MINUS_40=y in my prj.conf it still stays at the 3 dbm set as default.

Further, how can I change the advertisment and connection intervals?

Thanks very much

[Paul M.]

Ok manged to chenge the advertisment interval by using 

#define BT_LE_ADV_CONN_SLOW BT_LE_ADV_PARAM(BT_LE_ADV_OPT_CONNECTABLE, \
				       BT_GAP_ADV_SLOW_INT_MIN, \
				       BT_GAP_ADV_SLOW_INT_MAX, NULL)

for my bt_le_adv_start function.

Still struggleing to change the connection interval dynamically

[Einar Thorsrud]

The connection interval is decided by the central. However, the peripheral can request a connection parameter update with a different set of connection parameters, including interval. Use bt_conn_le_param_update() to initiate a connection parameter update procedure for a current connection.