When I switch into RTL mode APM immediately cuts my throttle to zero. My Sky Fun Jet does a beautiful job of gliding back to launch and circling, but the throttle never comes back on. I am guessing that APM cuts the throttle to descend, but shouldn't it power back up before reaching the ground? It's almost as if the commanded altitude is below ground level. Perhaps my cruise airspeed is set to low (10 ft/s) and the throttle is cut in an effort to slow down? I bumped it up to 15 ft/s but have not had a chance to try flying again yet. Any suggestions?
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on Saturday i flew at last with success. Stabilization and RTL worked perfect even in really strong wind.
Here is my setup:
aircraft is high-wing, 2m wings span, very stable one.
APM of version 1.02, MTK16, no changes in APM code, except GPS configuration in APM_config.h, no additional sensors, just APM + OILPAN 2.0 + MTK16.
I had no waypoints set yet, just wanted to test stabilization and RTL. Anyway Saturday event wasn't without problems. First flight was terrible - i even didn't try to switch on RTL because stabilization didn't work. After switching on the stabi, airframe started make big waves. It was high enough so i just only guess the elevator went to its max (pulled). After i landed switch off/on, got locked home and flew again, stabilization worked perfect. I had not yet stabilization system installed on my models, but this works great - no wavering just straight flight.
I flew farther from me (500 meters) then i switched to RTL and aircrat returned to me ;o). I repeated this maneuver 3 times (against the wind, down the wind) and it worked still perfect.
But i had problems with log - the log is enabled but after my flights in the CLI i got unpleasant message from APM - no logs available, even if i the logs enabled (all). I erased and enabled logs bot nothing is recorded. Have somebody hint on it?
Next weekend - i try auto mode and if there will be more free time, i try to load APM 2.011 (or latest one, if there will be more recent).
i retraced some of my steps too. i also noticed that my stabilize mode is not working. i switch to stabilize and the servos throw to max. the only thing i changed was added the battery monitoring code. so i commented out the battery monitoring code and reset and reloaded. now stabilize works. i switch to RTL and the plane throttles up while on the ground. its too windy to fly so i will report back later. maybe my post will have a clue to the problem.
Thanks
I really need to sit down and methodically record the steps that I make. I am a software tester by profession, as such this sort of thing comes naturally, but I just don't have the time to spend on the APM that I would like. Maybe a few hours a month, that's it. As a result I have to make multiple steps which doesn't make things easy to trace. Anyway, enough of the excuses.
Regarding versions - I have had this "no throttle" problem ever since I started working with APM - This was back in October last year, so I guess v1.0. It was still in beta for sure. Every so often, you'll make a few tweaks to config.h, write it to the APM (Almost universally, I stick to Arduino for this) and pabaa...! Switch to any mode other than manual, and your throttle stick does nothing. Even modes where some semblance of airspeed needs to be maintained (RTL, Auto etc) there is no motor.
I am running a MTK GPS. The firmware - good question. It's as it was delivered from the DIY drones store last October. The only other off-board sensor is the DIY drones supplied airspeed sensor. Arduino was v21 when I started out now 22 IIRC. For reference I upgraded to APM 2.0 and had the same problem creep up.
My radio is perhaps a slightly left-field choice - I use Sanwa Airtronics radios (in the case of my APM equipped Skyfun it's an RDS8000 2.4 unit with matching 8ch Sanwa Airtronics Rx. I guess most people use Futabas or cheapo Hobbyking kit.
One thing I have noticed though is that the Mission Planner does some bizarre stuff. Keeps telling me my port is potentially in use / cannot read or write to the board sometimes. When it does read from APM, some of the field continue to display "Loading". I've given up on the mission planner until I'm happy it's not screwing my APM software or config. I justify this in that I made a read from APM of four waypoints, modified them slightly then wrote them back to APM. After this and this alone, my elevator was reversed in any mode other than manual. Utterly bizarre. I did a factory reset and re-config'd the radio to no avail. Only a re-write of the software via Arduino could fix it.
Similarly, I had it fly a mission last weekend. Worked great. I landed, performed a reset of the APM, launched and when I switched to Auto, the APM simply tried to fly the thing into the deck...! It tried to follow the waypoints, but at what altitude I don't now - sure as heck wasn't the 100m agl I had programmed and successfully run 5 minutes previously.
Anyway, I digress. I promise to be more methodical in my approcha from now on (yes, it means I cannot advance as quick) but if it helps find this bug it's well worth it...!
Please let me know what othe rinfo I can supply. More than happy to help, even if my time is somewhat limited.
I have had this same problem numerous times. The only thing I can pin it down to it sometimes the mission planner screws things up. Generally, no amount of resetting / factory config will sort it. Re-programming the firmware to the device via Arduino usually solves it for me.
Yes, the throttle should come back on when the aircraft is at the requested altitude and speed. Your cruise airspeed is indeed very low for a Skyfun. I'd set it to at least 3x that, and ideally 5x.
Replies
Guys,
on Saturday i flew at last with success. Stabilization and RTL worked perfect even in really strong wind.
Here is my setup:
aircraft is high-wing, 2m wings span, very stable one.
APM of version 1.02, MTK16, no changes in APM code, except GPS configuration in APM_config.h, no additional sensors, just APM + OILPAN 2.0 + MTK16.
I had no waypoints set yet, just wanted to test stabilization and RTL. Anyway Saturday event wasn't without problems. First flight was terrible - i even didn't try to switch on RTL because stabilization didn't work. After switching on the stabi, airframe started make big waves. It was high enough so i just only guess the elevator went to its max (pulled). After i landed switch off/on, got locked home and flew again, stabilization worked perfect. I had not yet stabilization system installed on my models, but this works great - no wavering just straight flight.
I flew farther from me (500 meters) then i switched to RTL and aircrat returned to me ;o). I repeated this maneuver 3 times (against the wind, down the wind) and it worked still perfect.
But i had problems with log - the log is enabled but after my flights in the CLI i got unpleasant message from APM - no logs available, even if i the logs enabled (all). I erased and enabled logs bot nothing is recorded. Have somebody hint on it?
Next weekend - i try auto mode and if there will be more free time, i try to load APM 2.011 (or latest one, if there will be more recent).
Thanks
Erik
Hi Chris,
I really need to sit down and methodically record the steps that I make. I am a software tester by profession, as such this sort of thing comes naturally, but I just don't have the time to spend on the APM that I would like. Maybe a few hours a month, that's it. As a result I have to make multiple steps which doesn't make things easy to trace. Anyway, enough of the excuses.
Regarding versions - I have had this "no throttle" problem ever since I started working with APM - This was back in October last year, so I guess v1.0. It was still in beta for sure. Every so often, you'll make a few tweaks to config.h, write it to the APM (Almost universally, I stick to Arduino for this) and pabaa...! Switch to any mode other than manual, and your throttle stick does nothing. Even modes where some semblance of airspeed needs to be maintained (RTL, Auto etc) there is no motor.
I am running a MTK GPS. The firmware - good question. It's as it was delivered from the DIY drones store last October. The only other off-board sensor is the DIY drones supplied airspeed sensor. Arduino was v21 when I started out now 22 IIRC. For reference I upgraded to APM 2.0 and had the same problem creep up.
My radio is perhaps a slightly left-field choice - I use Sanwa Airtronics radios (in the case of my APM equipped Skyfun it's an RDS8000 2.4 unit with matching 8ch Sanwa Airtronics Rx. I guess most people use Futabas or cheapo Hobbyking kit.
One thing I have noticed though is that the Mission Planner does some bizarre stuff. Keeps telling me my port is potentially in use / cannot read or write to the board sometimes. When it does read from APM, some of the field continue to display "Loading". I've given up on the mission planner until I'm happy it's not screwing my APM software or config. I justify this in that I made a read from APM of four waypoints, modified them slightly then wrote them back to APM. After this and this alone, my elevator was reversed in any mode other than manual. Utterly bizarre. I did a factory reset and re-config'd the radio to no avail. Only a re-write of the software via Arduino could fix it.
Similarly, I had it fly a mission last weekend. Worked great. I landed, performed a reset of the APM, launched and when I switched to Auto, the APM simply tried to fly the thing into the deck...! It tried to follow the waypoints, but at what altitude I don't now - sure as heck wasn't the 100m agl I had programmed and successfully run 5 minutes previously.
Anyway, I digress. I promise to be more methodical in my approcha from now on (yes, it means I cannot advance as quick) but if it helps find this bug it's well worth it...!
Please let me know what othe rinfo I can supply. More than happy to help, even if my time is somewhat limited.
Thanks for the continued support.
Rup