| .. _bluetooth_direction_finding_connectionless_tx: |
| |
| Bluetooth: Direction Finding Periodic Advertising Beacon |
| ######################################################## |
| |
| Overview |
| ******** |
| |
| A simple application demonstrating the BLE Direction Finding CTE Broadcaster |
| functionality by sending Constant Tone Extension with periodic advertising PDUs. |
| |
| |
| Requirements |
| ************ |
| |
| * nRF52833DK board with nRF52833 SOC |
| * antenna matrix for AoD (optional) |
| |
| Building and Running |
| ******************** |
| |
| This sample can be found under :zephyr_file:`samples/bluetooth/ |
| direction_finding_connectionless_tx` in the Zephyr tree. |
| |
| By default the application supports Angle of Arrival and Angle of Departure |
| mode. |
| |
| To use Angle of Arrival mode only, build this application as follows: |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/bluetooth/direction_finding_connectionless_tx |
| :host-os: unix |
| :board: nrf52833dk_nrf52833 |
| :gen-args: -DOVERLAY_CONFIG=overlay-aoa.conf |
| :goals: build flash |
| :compact: |
| |
| See :ref:`bluetooth samples section <bluetooth-samples>` for common information |
| about bluetooth samples. |
| |
| Antenna matrix configuration |
| **************************** |
| |
| To use this sample with Angle of Departure enabled, additional GPIOS configuration |
| is required to enable control of the antenna array. Example of such configuration |
| is provided in :zephyr_file:`samples/bluetooth/direction_finding_connectionless_tx/boards/ |
| nrf52833dk_nrf52833.overlay`. |
| |
| :zephyr_file:`samples/bluetooth/direction_finding_connectionless_tx/boards/ |
| nrf52833dk_nrf52833.overlay` is a device tree overlay that provides information |
| about which GPIOS should be used by Radio peripheral to switch between antenna |
| patches during CTE transmission in AoD mode. At least two GPIOs must be provided |
| to enable antenna switching. GPIOS are used by Radio peripheral in order following |
| indices of :code:`dfegpio#-gpios` properties. The order is important because it |
| affects mapping of antenna switch patterns to GPIOS (see `Antenna patterns`_). |
| |
| Antenna patterns |
| **************** |
| The antenna switch pattern is a binary number where each bit is applied to |
| a particular antenna GPIO pin. For example, the pattern 0x3 means that antenna |
| GPIOs at index 0,1 will be set, and following are left unset. |
| |
| This also means that, for example, when using four GPIOs, the patterns count |
| cannot be greater than 16 and maximum allowed value is 15. |
| |
| If the number of switch-sample periods is greater than the number of stored |
| switch patterns, then the radio loops back first pattern. |
| |
| To successfully use Direction Finding Beacon with AoD mode enabled provide |
| following data related with owned antenna matrix design: |
| |
| * provide GPIO pins to :code:`dfegpio#-gpios` properties in |
| :zephyr_file:`samples/bluetooth/direction_finding_connectionless_tx/boards/nrf52833dk_nrf52833.overlay` |
| file |
| * provide default antenna that will be used to transmit PDU :code:`dfe-pdu-ant` |
| property in |
| :zephyr_file:`samples/bluetooth/direction_finding_connectionless_tx/boards/nrf52833dk_nrf52833.overlay` |
| file |
| * update antenna patterns in :cpp:var:`ant_patterns` array in |
| :zephyr_file:`samples/bluetooth/direction_finding_connectionless_tx/src/main.c`. |
