Bluetooth: Direction Finding Central and Peripheral Sample Code

[mgl]

When working with the direction finding central code, would we need to have the antenna array connected to the central development kit and then have another kit running the regular Bluetooth: peripheral sample code? I am working with the nrf5340 development kits and u-blox ANT-B10 antenna array board. I am also having trouble finding the correct connector for the antenna array board. Any help would be greatly appreciated. 

[Elfving]

Hi,

You are right on track.

Use the antenna connector J1, right at the end of the DK, above the logo.

 

For more on how direction finding works, I hope you've seen the WP on it. Though note that there might be some discrepancies between what the WP states and how the BT SIG spec defines its function, since the WP is mainly focused on the HW capabilities on the nRFs.

Regards,

Elfving

[mgl]

I understand that I need to use the antenna connector J1 but what part do I need to make this connection?

[Elfving]

mgl said:

And would I need to flash any code on the antenna array board and power it?

Well yes you would have to power it. And I assume you do not need to flash anything to it.

Though I am not sure about the specifics here. It would be best to check this with the docs from u-blox.

mgl said:

Would an nrf5340 be compatible for the tag with the antenna array having the nrf52833?

Yes, given that the u-blox solution follows the spec.

Regards,

Elfving

[mgl]

Which antenna array are you using above? Does it work for AoA solutions? I’m being told that the u-blox ANT-B10-00C is not made for developing third-party solutions so it wouldn’t work even though the Nordic website says any antenna array would work. 

[Elfving]

mgl said:

I’m being told that the u-blox ANT-B10-00C is not made for developing third-party solutions

Great. I'm interpreting that is it following the spec, and providing the default AOA solution.

mgl said:

Which antenna array are you using above?

What do you mean by "above" here?

Regards,

Elfving

[mgl]

Are you saying that the u-blox ANT-B10-00C should work while u-blox is saying it wouldn’t work for my application of indoor tracking?

[Elfving]

I am not sure if I understand. Does ublox say that  ANT-B10-00C wouldn’t work for my application of indoor tracking?

They know their products better than I do. 

What I was trying to say in that previous response of mine, was that if you require a cable for the antenna array, get the correct one. Though as it turns out, it looks as if the ublox product doesnt require one, since the NRF and the antenna looks to be on the same board.

Regards,

Elfving

[mgl]

That’s what I was told yesterday. However, today they are saying that all the ANT-B10-00C needs is a host board that can handle the UART connection and associated pins in the ANT-B10-00C interface. Would the nrf5340 be able to handle this?

[Elfving]

Hmm... yeah I guess so.

Did they say anything about what the onboard NINA-B411 helped out with BLE-wise? I guess it could be that it does not.

Regards

[mgl]

This is what I've been told, "The ANT-B10 antenna board has a NINA-B4 module with an nRF52833 chip inside that does the angle calculations. It then outputs the angles as AT events over the UART, so you need a host that can take care of the angles and do the processing. This host can be for example an STM32 or other MCU, it does not need to have Bluetooth AoA capability." 

[Elfving]

Ah I see. Yeah the NRF53, along with all other nRFs, do use UART.

You can connect this to an nRF53 with no problem. For more on how to continue this, you can for instance have a look at our DevAcademy course on UART, or a UART sample on how to work with it.

Regards,

Elfving

[mgl]

Would you happen to know how I could connect lab cables to the ANT-B10-00C? That is currently what I am having issues with as the antenna array board connections aren't originally set up to make UART connections since it has the 20-pin header.