Configuration of CTE data transmission and reception in low-power Bluetooth AOD mode using nrf5340dk

[xu shengxian]

This is the video of my configuration process.

I want to use nfr5340-dk to achieve the transmission and reception of CTE data in low-power Bluetooth AOD mode. I imported the code for wireless transmission and reception in the SDK and configured it according to the example provided on the official website, but I did not successfully receive CTE data. It may be due to some errors in the configuration process. Could you please help me check which step went wrong? During this transmission and reception process, I used two NFR5340-DKs, which come with a built-in Bluetooth antenna. I do not have an external antenna matrix, so is it because my antenna switching mode is wrong? If I don't have an external antenna matrix, how should I configure it? The following are the steps and results of configuring according to the configuration tutorial provided on the official website:

Bluetooth: Direction finding connectionless beacon

I didn't make any additional configurations, I just chose nrf5340dk as the development board

Bluetooth: Direction finding connectionless locator

1.To build this sample with AoD mode only, set OVERLAY_CONFIG to the overlay-aod.conf file.

2.To build this sample for nRF5340 DK, with AoD mode only, add content of overlay-aod.conf file to child_image/hci_ipc.conf file.

3.Result：Configured to only use AOD mode.

The result of programming the code onto the board

beacon:

locator:

Obviously, it did not receive the CTE data sent by the sender.

[xu shengxian]

[xu shengxian]

Hello, thank you very much for your help! But maybe I still need to ask some questions. Thank you in advance!

I saw a person on the Internet who encountered the same problem as me a few months ago.：(+) I cannot get AOA data in ncs2.4.0 sample: direction_finding_connectionless_rx - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

And you replied to him. I carefully read your communication. Finally, you did an experiment, saying that it was because he did not use the SWF cable, but I only saw successful examples:

1.Did you encounter my problem when you only used the PCB antenna with two boards instead of using the SWF cable?

[DEVICE]: 6E:A9:63:DD:76:95 (random), AD evt type 0, Tx Pwr: 127, RSSI -88  C:1 S:1 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 ms), SID: 255
[DEVICE]: 25:69:F1:44:7C:1E (random), AD evt type 3, Tx Pwr: 127, RSSI -72  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 ms), SID: 255
success. Found periodic advertising.
Creating Periodic Advertising Sync...ASSERTION FAIL [err == 0] @ WEST_TOPDIR/zephyr/subsys/bluetooth/host/hci_core.c:330
*** Booting Zephyr OS build v3.3.99-ncs1-1 *** -11
Starting Connectionless Locator Demo
Bluetooth initialization...failed (err -11)
success
Scan callbacks register...success.
Periodic Advertising callbacks register...success.
Start scanning...failed (err -11)
Waiting for periodic advertising...

2.If I use AOD mode, do I only need to connect the antenna array with SWF cable at the trasmitting end, and the receiving end only needs to use PCB antenna to create synchronization, and then the receiving end can access CTE data?

Looking forward to your reply! Thank you in advance for your help!

[Elfving]

xu shengxian said:

using my previous configuration, and connecting an antenna array to nrf5340dk through a UFL connector and configuring antenna switching mode can successfully achieve synchronization and receive CTE data?

Yes, using the correct antenna connector in J1 is what is stopping you from getting a connection there. Though as Paal in the chat here pointed out, I was wrong in calling it UFL, its SWF. 

If you are struggling with the same thing as the customer in the thread you are linking to, then the antenna connector is what is stopping you.

xu shengxian said:

1.Did you encounter my problem when you only used the PCB antenna with two boards instead of using the SWF cable?

I got the error that it doesn't sync and receive anything. Though I do not think I got err-11.

xu shengxian said:

2.If I use AOD mode, do I only need to connect the antenna array with SWF cable at the trasmitting end, and the receiving end only needs to use PCB antenna to create synchronization, and then the receiving end can access CTE data?

Yeah that sounds correct. For more info on Direction finding, I would recommend having a look at our whitepaper on it.

Regards,

Elfving