How to filter out the target AoA tag

[Tom.Fu]

Hi Support Team

If the advertising packet of the AoA tag is structured like the screenshot below, can the Nordic's direction finding locator filter out the target tag by the information circled by the red box in the below screenshot and the user can parse out these information on the Application Layer? We would like to filter out target tags and get their CTE for the location calculating. Many thanks.

[Hieu]

Hello Tom,

Unfortunately, all the people who work on this topic is out of office today. However, they will return next week, and will help you soon.

Our apology for the inconvenience.

Hieu

[Tom.Fu]

Hi Hieu

Got it and many thanks for assistance. 

[Simonr]

Hi

The format you refer to seems like the format Quuppa uses. Since they use a proprietary solution for Direction Finding, we don't think this AoA packet format will be compatible with our receiver code. Since the data you refer to here is in the payload section, the filtering must be done on the application layer here, something the Bluetooth compliant AoA solution does on a lower level, so I'm afraid this will not be straight forward. You can try contacting Quuppa about this, but I'm not sure you'll be able to get anywhere.

Best regards,

Simon

[Tom.Fu]

Hi

Glad to see your reply, because of this is our first time to learn the AoA solution.

Our goal is to get the advertise packet, read the payload and filter out the target tag by the information circled by the red box in the previous screenshot and get the CTE. Is it possible? 

And below are my questions after I research the receiver code.

Is the payload section of the received advertisement stored in buffer the below screenshot refer to?

And the payload is also structured like the screenshot below? if so, could I get the information circled by the red box in the previous screenshot for the target tag filtering?

I find that there's some filter option provided in the code, does these options must be considered if use the filter on the application layer mentioned above?

 

[Simonr]

Hi

Tom.Fu said:

Our goal is to get the advertise packet, read the payload and filter out the target tag by the information circled by the red box in the previous screenshot and get the CTE. Is it possible? 

Are you using a Quuppa AoA tag and an nRF52833 with the Nordic implementation of the receiver here? If so I don't think that will be possible, no. 

If you're new to Direction Finding I would recommend reading our white paper on Direction Finding here to get more insight into the process.

Yes, the advertising data is stored in this buffer if I'm not mistaken. Regarding the advertising packet, that's not how Direction finding packets are working I'm afraid. In the Bluetooth solution of Direction Finding, the advertiser and receiver will agree on synchronized advertising, that will then allow the advertiser to send a continuous tone extension with the Direction Finding data that the receiver will receive as IQ data. Once received, the receiver will need to convert this raw IQ data into vector form to be reviewed correctly. 

We don't have any specific sample code showing this, but you can check out this page for information on the various formulas used to translate IQ data between polar and rectangular form. 

I do not see how the filters are relevant here, and I don't think you need to worry about these for now.

Best regards,

Simon