P Waypoint

http://ardupilot-mega.googlecode.com/svn/ArduPilotMegaImages/missionplanner2.PNG

Instructions

You can enter waypoints and other commands (see below for the full list). In the dropdown menus on each row, select the command you want. The column heading will change to show you what data that command requires. Lat and Lon can be entered by clicking on the map. Altitude is relative to your launch altitude, so if you set 100m, for example, it will fly 100m above you.

Note that if the "Absolute Alt" box is checked, the altitude used will be altitude above sea level, NOT altitude above your launch position. If that box is unchecked, ALT will be relative altitude, so 100m will be 100m above your "home" altitude, or where you're probably standing.

Default Alt is the default altitude when entering new waypoints. It's also the altitude RTL (return to launch) mode will fly at if you have "Hold Default ALT" checked; if you don't have that checked, your aircraft will try to maintain the altitude it was at when you switched on RTL.

Verify height means that the Mission Planner will use Google Earth topology data to adjust your desired altitude at each waypoint to reflect the height of the ground beneath. So if your waypoint is on a hill, if this option is selected the Mission Planner will increase your ALT setting by the height of the hill. This is a good way to make sure you don't crash into mountains!

Once you are done with your mission, select "Write" and it will be sent to APM and saved in EEPROM. You can confirm that it's as you wanted by selecting "Read"

You can save multiple mission files to your local hard drive by selecting "Save WP File" or read in files with "Load WP File".

Basic waypoint commands

A mission file is a little intimidating to the human eye, but is a powerful scripting language for the autopilot. (Again, remember that the GCS will soon take care of all of this for you. You shouldn't have to see it yourself for long!).

You can have as many commands as you want, ranging from pre-programmed ones to ones that you can create. Here are some common ones:

• {NAV_WAYPOINT n/a, alt, lat, lon}
• {NAV_TAKEOFF pitch, target altitude}
• {NAV_LAND n/a, alt, lat, lon}
• {DO_JUMP waypoint, n/a, repeat count, n/a} Goes to that waypoint and resumes mission there. Set repeat count to any number greater than 1 to do it that many times. or to -1 to do it forever. Good for looping missions.

In the screenshot above, I've planned a mission that starts with an autotakeoff to 20m attitude, the three waypoints at 100m, ending with one that sets up a landing pattern. Finally an autoland finishes the mission at 0m altitude.

Note: When you're using the Jump command, remember that waypoint logic can be a bit confusing. A waypoint command means "start heading to this WP", not "wait until you get to this WP." So, for example, if you put a "Jump to WP1" command in-between WP4 and WP5, the aircraft will never get to WP5. That's because once it starts heading in the direction of WP5, it then executes the next command, which is the jump, and that takes priority. So in that instance, if you want the aircraft to hit WP5, you'd create a fake WP6 and issue the Jump command after that.

You can read more about auto landing and takeoff here.

A full guide to MAVLink command syntax is in the appendix here.

Tips

• Prefetch: You can cache map data so you don't need Internet access at the field. Click the Prefetch button, and hold down Alt to draw a box to download the selected imagery of a location.
• Grid: This allows you to draw a polygon (right click) and automatically create waypoints over the selected area. Note that it does not do "island detection", which means if you have a big polygon and a little one inside of that, the little one will not be excluded from the big one (see this for more). Also, in the case of any polygon that partialy doubles backs on itself (like the letter U), the open area in the center will be included as part of the flyover.
• Setting your home location to the current location is easy, just click "Home Location" above where you enter your home location, and it will set your home location to the current coordinates.