da02f6a39b
Create platforms/zephyr/hci.py with definitions of vendor HCI commands to read and write TX power. Add documentation for how to prepare an nRF52840 dongle with a Zephyr HCI USB firmware application that includes dynamic TX power support and how to send a write TX power vendor HCI command from Bumble.
1.7 KiB
:material-memory: ZEPHYR PLATFORM
Set TX Power on nRF52840
The Nordic nRF52840 supports Zephyr's vendor specific HCI command for setting TX power during advertising, connection, or scanning. With the example HCI USB application, an [nRF52840 dongle](https://www.nordicsemi.com/Products/Development- hardware/nRF52840-Dongle) can be used as a Bumble controller.
To add dynamic TX power support to the HCI USB application, add the following to
zephyr/samples/bluetooth/hci_usb/prj.conf and build.
CONFIG_BT_CTLR_ADVANCED_FEATURES=y
CONFIG_BT_CTLR_CONN_RSSI=y
CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y
Alternatively, a prebuilt firmware application can be downloaded here: hci_usb.zip.
Put the nRF52840 dongle into bootloader mode by pressing the RESET button. The
LED should pulse red. Load the firmware application with the nrfutil tool:
nrfutil dfu usb-serial -pkg hci_usb.zip -p /dev/ttyACM0
The vendor specific HCI commands to read and write TX power are defined in
bumble/vendor/zephyr/hci.py and may be used as such:
from bumble.vendor.zephyr.hci import HCI_Write_Tx_Power_Level_Command
# set advertising power to -4 dB
response = await host.send_command(
HCI_Write_Tx_Power_Level_Command(
handle_type=HCI_Write_Tx_Power_Level_Command.TX_POWER_HANDLE_TYPE_ADV,
connection_handle=0,
tx_power_level=-4,
)
)
if response.return_parameters.status == HCI_SUCCESS:
print(f"TX power set to {response.return_parameters.selected_tx_power_level}")