PX4-Autopilot/docs/en/mavlink/mavlink_profiles.md

MAVLink Profiles

A MAVLink profile (also called a mode) defines a set of messages that can be streamed by default on a MAVLink channel and their rates.

This section lists the profiles, and explains how they can be used and extended.

Available Profiles

The available profiles (in source-code declaration order) are:

• Normal (MAVLINK_MODE_NORMAL): Set of messages for a GCS.
• Onboard (MAVLINK_MODE_ONBOARD): Set of messages for a companion computer on a fast link (such as Ethernet).
• Gimbal (MAVLINK_MODE_GIMBAL): Messages for a gimbal. Note this also enables message forwarding.
• External Vision (MAVLINK_MODE_EXTVISION): Messages for offboard vision systems.
• External Vision Minimal (MAVLINK_MODE_EXTVISIONMIN): Messages for offboard vision systems on slower links.
• OSD (MAVLINK_MODE_OSD): Set of messages for an OSD system.
• Magic (MAVLINK_MODE_MAGIC): No messages streamed by default. Used when configuring streaming dynamically via MAVLink.
• Custom (MAVLINK_MODE_CUSTOM): Same as MAVLINK_MODE_MAGIC.
• Config (MAVLINK_MODE_CONFIG): Set of messages for configuration interface, sent at higher rates. This is used, for example, to send the MAVLINK_MODE_NORMAL message set via USB to a GCS.
• Iridium (MAVLINK_MODE_IRIDIUM): Streams HIGH_LATENCY2 message to an iridium satellite phone.
• Minimal (MAVLINK_MODE_MINIMAL): Minimal set of messages for use with a GCS on a poor telemetry link.
• Onboard Low Bandwidth (MAVLINK_MODE_ONBOARD_LOW_BANDWIDTH): Set of messages to be streamed to a companion computer for re-routing to a reduced-traffic link, such as a GCS.
• Low Bandwidth (MAVLINK_MODE_LOW_BANDWIDTH): Reduced message set for low bandwidth links.
• uAvionix (MAVLINK_MODE_UAVIONIX): Messages for a uAvionix ADS-B beacon.
• Distance Sensor (MAVLINK_MODE_DISTANCE_SENSOR): Streams distance sensor data at unlimited rate.

:::tip The profile defines the default messages and rates. A connected MAVLink system can still request the streams/rates it wants using MAV_CMD_SET_MESSAGE_INTERVAL. :::

To find the exact messages in each profile, search for configure_streams_to_default (or the above profile names) in mavlink_main.cpp.

Assigning Profiles to Ports

MAVLink Peripherals explains how to set up a port for communicating over MAVLink. This uses the concept of an abstract MAVLink instance which is then assigned to a serial port.

The profile associated with a particular MAVLink instance is set using the associated MAV_X_MODE parameter:

• MAV_0_MODE
• MAV_1_MODE
• MAV_2_MODE

There are also dedicated profile parameters for ports that are not configured via MAVLink instances:

• USB_MAV_MODE: Profile for the USB port (used when MAVLink is set or detected on USB).
• MAV_S_MODE: Profile for the internal SOM (System on Module) to FMU communication channel, used on boards where the FMU and companion computer are co-located on the same module.

Note that not all profiles can necessarily be set on these ports.

Adding Messages to a Profile

You can add messages to a profile in appropriate case switch in the Mavlink::configure_streams_to_default(const char *configure_single_stream) method (see mavlink_main.cpp).

If you're testing with a GCS over USB you might add the message to the MAVLINK_MODE_CONFIG case using the configure_stream_local() method. For example, to stream BATTERY_STATUS_DEMO at 5 Hz:

	case MAVLINK_MODE_CONFIG: // USB
		// Note: streams requiring low latency come first
		...
		configure_stream_local("BATTERY_STATUS_DEMO", 5.0f);
        ...

See Streaming MAVLink Messages for a more detailed example.