Adding CTE field

[Luke_123]

Hi,

I want to implement AoA feature for our BLE beacons. I understand that I should add a CTE field to the packet, and rest of the job will be done by the receiver. Please correct me if I am wrong.

how can I make sure that the CTE is being added to the ADV packets ? Can I use the nRF sniffer at the RX side to see the CTE field ?

[Sigurd]

Hi,

I want to implement AoA feature for our BLE beacons.

We have a sample for this here: 

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/direction_finding_connectionless_tx/README.html

https://github.com/nrfconnect/sdk-nrf/tree/main/samples/bluetooth/direction_finding_connectionless_tx

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/getting_started.html

[Luke_123]

Hi Sigurd,

We are using the solar beacon code for some reasons, and doing the changes as below:

NRF_RADIO->DFEMODE = RADIO_DFEMODE_DFEOPMODE_AoA;

NRF_RADIO->DFECTRL1 = 3 << RADIO_DFECTRL1_NUMBEROF8US_Pos | 1 << RADIO_DFECTRL1_DFEINEXTENSION_Pos;

What is the easiest way to test whether CTE is added or not on the receiver side ?

[Sigurd]

Luke_123 said:

What is the easiest way to test whether CTE is added or not on the receiver side ?

I tested with the sample direction_finding_connectionless_tx on a nRF52833-DK.

I used another nRF52833-DK with the nRF Sniffer, and saw this:

[Luke_123]

Hi Sigurd,

Thank you for your reply.

I see from your snapshot that you are doing an extended scanning with wireshark. can a legacy scanning detect CTE ?

#

Please see the output from my sniffer, I cant detect CTE. I have added CTE to legacy advertising packets. Do I need to do any change in the wireshark/nrfsniffer settings to see the CTE ?

[Sigurd]

Hi,

From the Technical Overview document found here,

https://www.bluetooth.com/bluetooth-resources/bluetooth-direction-finding/

page 19: "Connectionless direction finding makes use of Bluetooth periodic advertising and the CTE is appended to otherwise standard ADV_EXT_IND PDUs. "