I had a full afternoon of test flights this weekend, with mostly encouraging results. I flew ArduPilots (with uBlox) on the EasyStar (rudder and elevator), EasyGlider (ailerons and elevator) and SuperStar (a high-wing trainer with ailerons and elevator). The good news is that the default easystar.h config file will fly both the EasyStar and SuperStar pretty much out of the box. Navigation isn't as tight as it would be after you tune the settings, but it works.
I also flew a GWS Formosa with AttoPilot. Stabilization worked fine, but the plane kept descending in automode, requiring a manual takeover before it hit the ground, so I've got a message into Dean to see what's wrong.
With ArduPilot one weird issue showed up. With the EasyStar, altitude hold didn't work. The plane kept rising and rising, requiring me to eventually switch into manual. But altitude worked great with the EasyGlider and SuperStar, with an identical setup and code. Odd. We're trying to diagnose this, but one thing that may be meaningful is that altitude readings aren't showing up in the Ground Station software (it just shows 0, regardless of the vertical position of the plane). Maybe a bum uBlox module? Some strange code bug? Not sure....
I don't see any effected while flying my EZ* either in cloudy or clear day now. I have enlarge my rudder. Change radius limit to 80m, get best flight results until now with v2.3.1 code. But with v2.4 I get FULL throttle all the time. Maybe have some bugs with airspeed sensor code.
uBlox from DIYdrones store are programmed to only lock in 3D mode (no 2D)... So if you seee the nice blue LED is because you have enough sats for 3D mode. If i bind several times my easystar the altitude problem disappears, but then for no reason (in another day) the problem comes backs, weird..
Can the ublox give you a valid lock with only 3 satellites? Some GPS units can be configured to give a "2D lock", assuming the WGS-84 geoid altitude as the fourth sphere. That could explain the behavior, and why it might not repeat.
I've got some more diagnostics to do. On the Superstar, with the exact same Autopilot hardware and code, the altitude shows up fine in the ground station. But not with the EasyStar. I tried changing all sorts of settings in the altitude and pitch PIDs configurations, but it made no difference. The throttle stays at one setting (possibly the max) and the plane keeps climbing. Meanwhile, the EasyGlider and SuperStar with the same hardware (actually the EasyGlider doesn't have a pitot tube, but they're otherwise the same) handle altitude fine.
I'm working with Jordi on this. We'll figure it out....
Comments
I'm working with Jordi on this. We'll figure it out....