nRF52811 Direction Finding (AoA) Where should I start?

RE: nRF52811 Direction Finding (AoA) Where should I start?

ColinC — Mon, 11 May 2020 08:15:56 GMT

Hi all,

I attended the Nordic Tech Tour webinar and was referred to this forum to ask for sample code regarding BLE AoA. Do you have any updates yet?

best regards,

Colin

RE: nRF52811 Direction Finding (AoA) Where should I start?

Dmitry — Sat, 12 Oct 2019 17:47:21 GMT

Nobody will give you a working solution, it depends on your array configuration and other factors. Here are two good articles from competitors:

http://dev.ti.com/tirex/content/simplelink_academy_cc2640r2sdk_2_30_02_00/modules/blestack/ble_aoa/ble_aoa.html

https://www.silabs.com/documents/public/presentations/ew-2018-understanding-advanced-bluetooth-angle-estimation-techniques-for-real-time-locationing.pdf

RE: nRF52811 Direction Finding (AoA) Where should I start?

xsdata — Sat, 12 Oct 2019 11:51:42 GMT

Hey Dmitry,

Thanks for inputs.

Any reliable logic / formula available to convert the array data into angle?

RE: nRF52811 Direction Finding (AoA) Where should I start?

Simonr — Fri, 11 Oct 2019 07:48:58 GMT

Hi guys

Dmitry is absolutely correct. We don't have any software examples for direction finding as of yet.

Thanks a lot for a great suggestion on how to get started on your own though Dmitry!

Best regards,

Simon

RE: nRF52811 Direction Finding (AoA) Where should I start?

Dmitry — Thu, 10 Oct 2019 17:31:09 GMT

Hi,

unfortunately there's still no support in SDK for direction finding... you have to write everything by yourself. Study the Bluetooth 5.1 Core Specification Vol 6 Part B and nRF52811 Product Specification chapter 6.14.12 - there's all information you need.

I would recommend to start from simple - first, write an app for a beacon to send an advertising packet with constant tone extension, then set up your board in AoA mode to receive I/Q samples and dump them to debug console as csv data that you can visualize, for example, in Excel to enjoy nice charts :) I can say that it's not too complex to set things up, everything works as expected at low level, the challenge is to interpret the data from your array and convert them to angle with reliable results, especially with indoor case.