Many serial (UART) ports on a Pixhawk board can be fully configured via parameters: e.g.:
- 在其他端口上运行 MAVLink ，或更改流消息
- 设置双 GPS
- 启用在串口上运行的传感器，例如某些 距离传感器 。
Some ports cannot be configured because they are used for a very specific purpose like RC input or the system console (
The following functions are typically mapped to the same specific serial ports on all boards, and are hence mapped by default:
- MAVLink 被映射到
Telem 1端口，端口的波特率为 57600 (对于遥测模块)。
- GPS 1 (gps driver) is mapped to the
GPS 1port with a baudrate Auto (with this setting a GPS will automatically detect the baudrate - except for the Trimble MB-Two, which requires 115200 baudrate).
- MAVLink is mapped to the Ethernet port using
MAV_2_CONFIGon Pixhawk devices that have an Ethernet port.
All other ports have no assigned functions by default (are disabled).
The port mappings above can be disabled by setting MAV_0_CONFIG, GPS_1_CONFIG, and MAV_2_CONFIG to Disabled, respectively.
All the serial drivers/ports are configured in the same way:
- Set the configuration parameter for the service/peripheral to the port it will use.
Configuration parameter names follow the pattern
*_CFG (QGroundControl only displays the parameters for services/drivers that are present in firmware).
At time of writing the current set is: GPS_1_CONFIG, GPS_2_CONFIG, ISBD_CONFIG, MAV_0_CONFIG, MAV_1_CONFIG, MAV_2_CONFIG, MODAL_IO_CONFIG, MSP_OSD_CONFIG, RC_PORT_CONFIG, TEL_FRSKY_CONFIG, TEL_HOTT_CONFIG, UXRCE_DDS_CFG, SENS_CM8JL65_CFG, SENS_LEDDAR1_CFG, SENS_SF0X_CFG, SENS_TFLOW_CFG, SENS_TFMINI_CFG, SENS_ULAND_CFG, SENS_VN_CFG, RC_CRSF_PRT_CFG, MXS_SER_CFG, UWB_PORT_CFG, DSHOT_TEL_CFG
- Reboot the vehicle in order to make the additional configuration parameters visible.
- Configure module-specific parameters (i.e. MAVLink streams and data rate configuration).
The GPS/Compass > Secondary GPS section provides a practical example of how to configure a port in QGroundControl (it shows how to use
GPS_2_CONFIG to run a secondary GPS on the
TELEM 2 port).
# Deconflicting Ports
Port conflicts are handled by system startup, which ensures that at most one service is run on a specific port. For example, it is not possible to start a MAVLink instance on a specific serial device, and then launch a driver that uses the same serial device.
At time of writing there is no user feedback about conflicting ports.
# Configuration Parameter Missing from QGroundControl
QGroundControl only displays the parameters for services/drivers that are present in firmware. If a parameter is missing, then you may need to add it in firmware.
PX4 firmware includes most drivers by default on [Pixhawk-series](../flight_controller/pixhawk_series.md) boards. Flash-limited boards may comment out/omit the driver (at time of writing this only affects boards based on FMUv2).
You can include the missing driver in firmware by enabling the driver in the default.px4board config file that corresponds to the board (opens new window) you want to build for. For example, to enable the SRF02 driver, you would a the following line to the px4board.
An easier method would be using boardconfig which launches a GUI where you can easily search, disable and enable modules. To launch boardconfig type
make <vendor>_<board>_<label> boardconfig
You will then need to build the firmware for your platform, as described in Building PX4 Software.