BLE params on nRF53

[Mehdi]

Hi,

Based on peripheral uart sample code on nRFConnect SDK 1.8, I'm developing a custom BLE application
under nRF5340 using VSCODE though nrfConnect extension.

In order to accelerate the data throughput, I'm trying to change the maximum throughput
by setting CONFIG_BT_CTLR_DATA_LENGTH_MAX to 251 on prj.conf and set the desired data length through bt_conn_le_data_len_update API.

Based on the Throughput example, I realized that CONFIG_BT_CTLR_DATA_LENGTH_MAX  params are associated to the network core of nRF53 so it should not be set on the project configuration file of the application core.

So :

1. How can I include CONFIG_BT_CTLR_DATA_LENGTH_MAX in the network core?
2. I want to know if connections interval, PHY and MTU Should be associated with the network core?
3. is there any way to change MTU on runtime instead of using menuconfig?

Best regards,

Mehdi.

[dejans]

Hi Mehdi, 

1. For nRF5340-DK, the additional configuration options for the network core such as CONFIG_BT_CTLR_DATA_LENGTH_MAX are taken from the "child_image" directory. 
    Please have a look at multi-image-builds and configuration of the child image.
   There is an example of the configuration file inside change_image folder in nrf\samples\bluetooth\throughput\child_image\hci_rpmsg.conf.
2. Yes, these parameters are related to the bluetooth controller and they should be associated with the network core
3. Menuconfig is the place where you set your MTU value. However, you can change this on runtime by using bt_gatt_exchange_mtu function. You can read more on the developer page exchange MTU.

Best regards,
Dejan