send MAV_CMD

[tommynanny]

hi, this might be a really silly question but I am trying to use golang to communicate with SITL at TCP port 5760 (docker). With gomavlib provided examples, I can pick up the mavlink message (heartbeat, battery, etc) from sitl, but I was wondering how I could send out MAV_CMD to sitl to instruct it to do certain tasks; commands such as
MAV_CMD_NAV_WAYPOINT
MAV_CMD_NAV_RETURN_TO_LAUNCH
MAV_CMD_NAV_TAKEOFF
MAV_CMD_NAV_LAND
I am very new to mavlink, any advice would be really appreciated!

[aler9]

Hello, in order to send commands, you have to follow the procedure described here:

https://mavlink.io/en/services/command.html

Therefore:

node.WriteMessageAll(&ardupilotmega.MessageCommandLong{
    TargetSystem: ID,
    TargetComponent: ID,
    Command: ardupilotmega.MAV_CMD_NAV_TAKEOFF,
})

In order to fill TargetSystem and TargetComponent, you have to listen for heartbeat message and find the system ID and component ID of your SITL drone.