Bluetooth 5.0 spec based command (LE Advertising Extension) not recognized by nRF52840-PDK BT chip controller.

[Anupam Roy]

Hi,

 I have recently purchased a nRF52840-Preview DK board with the purpose to test Bluetooth 5.0 Specification based features like LE advertising Extension and LE 2M PHY etc. I am using RPI3 board as host PC with bluez upstream stack - 5.48 and underlying Bluez kernel. And in nRF52840 board, I have flashed hci_uart Zephyr based utility to communicate with BT controller. Now, when I try to check the LMP supported command, I see that Controller does not support LE Advertising Extension or LE 2M PHY related commands. I also tried to fire LE Advertising Extension command like LE Set Extended Advertising Parameters command using hcitool utility (utility to send command directly to Chip HCI from Host SW stack) to check how the chip responds. The result is, Chip does not recognize the command and reports Command Complete event with error status as Unknown HCI command. Kindly help! I am completely stuck due to this. How to test BT 5.0 features using this board?

BR,

-Anupam Roy

[Keton]

Zephyr is a separate BLE stack different from Nordic supported Softdevices and SDK. BLE 5.0 works with nRF SDK14.2 and S132 from Nordic without any problems. As for Zephyr their web pages and forums are better place to ask Zephyr related questions.

[Anupam Roy]

Hi Keton,

 Thanks for quick reply. Actually this is first time, i am using a Nordic Product & I understand that Zephyr could be different from Nordic Supported SoftDevices. However, I am bit confused here. As I said, I am not using Zephyr BLE stack, BLE stack in use in this scenario is running in my Host RPI3 raspbian board which uses Bluez stack. I am only using Zephyr RTOS for UART communication with nRF52840 board, that's all. For that purpose, I have uploaded a hci_uart tool in nRF52840 board just to send HCI commands.

For the sake of clarity, I should tell you that i am assuming BT Chip Firmware is already flashed in nRF52840 board by default by Nordic. Hence, I am assuming that when i send HCI commands from my RPI3 Host to nRF52840 SOC, the Firmware in the SOC will return all supported commands supported by Chip firmware provided by Nordic for this board, and I expected to see BT 5.0 spec based commands in output result. Am I missing something? Kindly throw some light!

[Keton]

Nordic chips come from factory blank. Unless you are using custom board with desired firmware flashed by the manufacturer on it you'll have to flash nRF52 chip. What's on the nRF52 dictates how it works and the capabilities. So you'll need to upload Zephyr HCI firmware if you want to use Zephyr stack and your nRF SDK app+Softdevice if you want to use Nordic stack. nRF is general purpose microcontroller and requires application that translates HCI commands to BLE stack API calls. This is not a typical application and AFAIK Nordic doesn't support this out of the box (they have their own protocol).

I'm not familiar with Zephyr. I wasn't able to establish BLE connection using their HCI example code and BlueZ. Standard BLE 4.0 scanning worked ok though.

[Anupam Roy]

Hello Keton,

 I see. I think now I am getting your point a bit more clearly. What you are basically trying to say is..nRF52840 board will require chip firmware from Nordic to expose BT 5.0 capabilities, and that firmware is in the form of some softdevice, right? Actually I am completely new to the SoftDevice concept.I think that at least one thing is clear now that the current firmware or application running in my SOC is not supporting BT 5.0 commands.

Anyways, after taking your opinion, and by doing some google search, I came across something called s140 softdevice which seems to be applicable for nRF52840 board. Looks like I need to erase the Zephyr based hci_uart from my SOC and then upload this s140 thing to the SOC to expose BT 5.0 features. Am I right? And by the way, Could you please share some guide about how to flash this softdevice thing to my nRF52840-PDK SOC from Windows PC?

Much Thanks in Advance!