Having a lot of fun learning Mission Planner 1.3.12 with my new IRIS+ (loaded the latest AC 3.2 version a few days ago).
One thing I notice is that when I add a DO_CHANGE_SPEED command, two columns appear for the m/s speed setting (see attached screen capture). Has anyone else observed this little glitch? In any event, I guess there is probably no harm in entering the desired speed in both fields.
Note: In AC3.1.2 (and earlier) versions the speed change will only take effect after the current navigation command (i.e. waypoint command) completes. From AC3.2 onwards the vehicle speed will change immediately. Also note that in AC3.2 the speed parameter will be in the SECOND COLUMN, not the first column as in previous releases as shown in the screenshot above (this is to match the official MAVLINK protocol)
Perfect, thanks! (it was an auto WP survey grid that did populate the second speed column shown in the graphic).