Yeah, basically the XBee sends back everything that an ordinary plane would be showing the pilot on all the various dials - location, airspeed, altitude, attitude, heading, waypoint number, etc. The two main reasons for this are that we UAV builders are an inquisitive bunch and we like to see how our toy is behaving, and also that data can help you see how well it's doing, and spot errors before they cause problems, and if you decide to take over and fly manually you know what the plane is doing, so you're not jumping in blind. Also, it lets you plot the flights in Google Earth or something similar, so you can see where you flew and compare it to where you wanted to fly. If you don't want your UAV to send back all that data, then you don't need the XBee - I don't think it has the necessary bandwidth to handle video of much quality. If you want good-quality video relay, then something like that Range Video transmitter is what you want. Plus, the Range Video OSD can overlay telemetry data on the video, so you still get that data (although it'll be live only; pretty sure you can't log it that way).
"Tuning ArduPilot for your aircraft
Despite what you may have heard, there are no plug-and-play autopilots in the world ;-) Even the best autopilots need to be tuned for different airframes, configurations and use patterns, and doing so is a bit of a black art. ArduPilot is distributed tuned for a standard EasyStar in low wind conditions, and you should be able to use it pretty much as is for that. But just as every RC plane requires a little trimming to fly well, you'll find that your autopilot may peform better if you tweak various settings.
Our recommendation is that while you're first setting up ArduPilot for your aircraft, you do NOT use it to control the throttle. Rather than connecting the ESC through the ArduPilot, connect it straight to your RC receiver as usual. That way you can control the throttle manually while ArduPilot is controlling stabilization and navigation. The main reason for this is that it's very difficult to tune aircraft in the wind, especially if the throttle settings are not sufficient to make headway (when the aircraft is heading into the wind with a insufficient throttle setting, its ground speed may drop to zero, which will confuse the GPS navigation, which is based on ground speed). Manually keep the throttle high enough to make headway into the wind, and you'll find it much easier to observe and tweak stabalization and navigation gains.
For aircraft other than the EasyStar, you'll definitely need to change setting to get acceptable performance. Over time, we'll release additional [airframe].h settings files for other aircraft, starting with the EasyGlider, SuperStar EP and Funjet. Community members will no doubt share files for their own aircraft and over time this tuning process will get easier.
[The ArduPilot 2.3 code does not use the D term in the PID, so you only need to modify the P (proportional) and I (integrator terms). You can learn more about PID theory here.]
Here are some general guidelines on modifying the PID gain settings in Appendix 2:
First, the best way to set up stabilization is to do so in Fly-By-Wire mode. Disconnect the GPS on the ground, and then when you switch the autopilot on in the air, it will simply stabilize your RC controlling. Try it with your hands off the stick and then see how it recovers from rolls and pitching.
A general rule of thumb is to increase the proportional term until the plane starts to wing rock (roll) or porpoise (pitch), then reduce the P term to half that value. Then increase the I term until sufficient stability is achieved.
You can start with the default settings in the EasyStar.h file, but if you really want to optimize the autopilot for your aircraft and not overcontrol it. We recommend you start from very low values and build up. For example P=0.1 and I=0. And then increase P slowly until you see better response (.1).
Next, you can test navigation by trying RTL (Return to Launch) mode. This is the default mode for the up position of your RC transmitter's toggle switch. Point your plane away from you and switch into auto. It should return to you and circle overhead. Try from various directions, so you can see how the plane handles navigation into the wind, downwind, and crosswind. If everything checks out, you're ready to try waypoints."
Replies
"Tuning ArduPilot for your aircraft
Despite what you may have heard, there are no plug-and-play autopilots in the world ;-) Even the best autopilots need to be tuned for different airframes, configurations and use patterns, and doing so is a bit of a black art. ArduPilot is distributed tuned for a standard EasyStar in low wind conditions, and you should be able to use it pretty much as is for that. But just as every RC plane requires a little trimming to fly well, you'll find that your autopilot may peform better if you tweak various settings.
Our recommendation is that while you're first setting up ArduPilot for your aircraft, you do NOT use it to control the throttle. Rather than connecting the ESC through the ArduPilot, connect it straight to your RC receiver as usual. That way you can control the throttle manually while ArduPilot is controlling stabilization and navigation. The main reason for this is that it's very difficult to tune aircraft in the wind, especially if the throttle settings are not sufficient to make headway (when the aircraft is heading into the wind with a insufficient throttle setting, its ground speed may drop to zero, which will confuse the GPS navigation, which is based on ground speed). Manually keep the throttle high enough to make headway into the wind, and you'll find it much easier to observe and tweak stabalization and navigation gains.
For aircraft other than the EasyStar, you'll definitely need to change setting to get acceptable performance. Over time, we'll release additional [airframe].h settings files for other aircraft, starting with the EasyGlider, SuperStar EP and Funjet. Community members will no doubt share files for their own aircraft and over time this tuning process will get easier.
[The ArduPilot 2.3 code does not use the D term in the PID, so you only need to modify the P (proportional) and I (integrator terms). You can learn more about PID theory here.]
Here are some general guidelines on modifying the PID gain settings in Appendix 2:
First, the best way to set up stabilization is to do so in Fly-By-Wire mode. Disconnect the GPS on the ground, and then when you switch the autopilot on in the air, it will simply stabilize your RC controlling. Try it with your hands off the stick and then see how it recovers from rolls and pitching.
A general rule of thumb is to increase the proportional term until the plane starts to wing rock (roll) or porpoise (pitch), then reduce the P term to half that value. Then increase the I term until sufficient stability is achieved.
You can start with the default settings in the EasyStar.h file, but if you really want to optimize the autopilot for your aircraft and not overcontrol it. We recommend you start from very low values and build up. For example P=0.1 and I=0. And then increase P slowly until you see better response (.1).
Next, you can test navigation by trying RTL (Return to Launch) mode. This is the default mode for the up position of your RC transmitter's toggle switch. Point your plane away from you and switch into auto. It should return to you and circle overhead. Try from various directions, so you can see how the plane handles navigation into the wind, downwind, and crosswind. If everything checks out, you're ready to try waypoints."
ArduPilot Main Page
Everything you need for a complete setup
ArduPilot Manual
I think the GPS for range video or Remzibi is IN ADDITION to the GPS used for ArduPilot.
At this point in time. This may change, but I'm not sure.
easystar_ardupilot_parts_list.xls