AoA Tag Sample Application

This repository contains an example Tag application for use with u-blox C211 Bluetooth Direction Finding Anchor. It is intended to be flashed on the u-blox C209 Tag which comes bundled with a C211 in the XPLR-AOA-1 and XPLR-AOA-2 kits.

Getting the code

This repo uses Git submodules: make sure that once it has been cloned you do something like:

git clone repo_url --recursive

Or if you aleady cloned normally:

git submodule update --init --recursive

Setup

Building with SeS

• Download nRF Connect

• In nRF Connect go to Toolchain Manager and install it.

• Open the Toolchain Manager and download nRF Connect SDK 1.5.

• After download click Open IDE.

• In Segger Embedded Studio go to File -> open nRF connect SDK project.

• Select the cloned project folder (likely named c209-aoa-tag unless other was specified when cloning).

• Select the ubx_evkninab4_nrf52833 inside u-blox-sho-OpenCPU/zephyr folder as the board config.

• After SeS loaded the project you can build and flash.

Building with command line

• Open nRF Connect and open Toolchain Manager
• Right next to the "nRF Connect SDK v1.5.0" you have a dropdown, click "Open bash". This step is not required, but it will set up the necessary environment variables for you.
• cd to project folder
• west build -b ubx_evkninab4_nrf52833
• west flash
• west flash only should be enough for building + flashing after that, specifying the board is only needed on the first build.

Adding the CTE to advertise packets

Unfortunately this application does not yet utilize the brand new Direction Findning API in Zephyr as that was just released. This application will in the near future make use of the official BLE Direction Finding APIs. But for now the step below is required to enable the CTE on all advertisement packets. Replace NrfConnectPath\v1.5.0\zephyr\subsys\bluetooth\controller\ll_sw\nordic\hal\nrf5\radio\radio.c with the file zephyr_patch\radio.c.
To see what is changed refer to file radio_diff.patch. You can also apply the changes in radio_diff.patch.

Release vs. Debug build

The prj.conf is split into multiple files, first there is prj_base.conf and that contains all common config for both release and debug. Then there are prj_debug.conf and prj_release.conf, these contain configurations specific to debug or release, for example compiler optimization level and logging config. By default a debug build is made, to build release run west build -p -b ubx_evkninab4_nrf52833 -- -DRELEASE.

Running on other boards

This sample application primarily supports the u-blox C209 application board bundled together with the u-blox C211 in the XPLR-AOA-1.

However getting it up and running on other boards which either use NINA-B4 module (like NINA-B4-EVK) or a bare NRF52833 should only be a matter of selecting the appropriate board file.

Building the application to use with OpenCPU DFU Bootloader

C209 boards come pre flashed with a DFU bootloader. To build a binary that is compatible with that the CONFIG_FLASH_BASE_ADDRESS needs to be changed. If the pre-flashed bootloader has been erased or overwritten then flash the dfu_bootloader/mbr_nrf52_2.4.1_mbr.hex and dfu_bootloader/nrf52833_xxaa_bootloader.hex using using J-Flash Lite/nrfjprog or similar tool to restore it. See the following complete steps to build and flash.

• In menuconfig change "Flash Base Address" from 0x0 to 0x1000 (or uncomment CONFIG_FLASH_BASE_ADDRESS=0x1000 in prj_base.conf)
• Re-Run CMAKE and re-build
• Copy the zephyr.bin file from build/zephyr folder to dfu_bootloader.
• In dfu_bootloader run nrfutil pkg generate --hw-version 52 --sd-req 0x00 --application-version 0 --application zephyr.bin app.zip
• To enter DFU mode when an application is flashed hold down SWITCH_2 and click reset.
• In dfu_bootloader run nrfutil dfu serial -pkg app.zip -p COMXXX -b 115200 -fc 1
• Now the module will be flashed. It's also possible to keep the "Flash Base Address" to 0x1000 and develop as usual and flashing with SeS or west as it will flash the application on the correct address and it will be started by the open bootloader.

nrfutil executable for flashing with OpenCPU DFU Bootloader can be downloaded from here: https://github.com/NordicSemiconductor/pc-nrfutil/releases

Using the Sensors on the C209

The C209 application board comes with some sensors. Study src/production.c for example how to get data from the sensors.

Using the application

Please review the user guide for more details on how to use the XPLR-AOA-1 and XPLR-AOA-2 kits.

More information about the hardware kits

For more information about the hardware kits as well as ordering information, please visit the XPLR-AOA-1 product page and XPLR-AOA-2 product page.

License

The software in this repository is Apache 2.0 licensed and copyright u-blox with the following exceptions:

• The zephyr_patch/radio.c which is under SPDX-License-Identifier: Apache-2.0

In all cases copyright, and our thanks, remain with the original authors.