hi all, this is my first time on the forum so please let me know if anything i do/say is inappropriate/can be improved. thank you!
me and my friend have just flashed multiwii 2.3 into our hobbyking mega 2560 boards (i'm on a hexcopter, he's on a quadcopter). previously, he was using a kk2 board and i was previously using the same setup but on another firmware (not multiwii). both of us have expererienced a gradual loss in power after flying for around less than a minute to a couple of minutes. what happens is the copter requires more and more throttle to keep it in the air until eventually even at full power, the copter still descends to the ground
i am running mw 2.3 on a my tricopter too (using a arduino pro mini) to great results - flew for around half an hour yesterday and everything works great.
today i flashed mw 2.2 into my hexcopter and there is still the same problem. thus i am wondering if there is something that i'm doing wrong with the 2560 board
here are the details that i know:
- flies perfectly fine for the first minute/few seconds
- angle/self levelling mode is on throughout
- none of the motors or escs feel warm (i checked immediately after landing to be sure)
- checking from my phone (connected by bluetooth) the motor outputs seem to range from 1500~1700 when i give it full throttle (and it still descends)
does anyone else here have this problem? really hope to get my hexcopter up and flying again. thank you!
Hexcopter/quadcopter losing throttle power after awhile
Re: Hexcopter/quadcopter losing throttle power after awhile
Strange....
first thought is weak battery, but I assume that would have crossed your mind already, and it wouldn't fly on KK as well....
The 2560 boards are not really different from pro mini in setup
These might be obvious, but did you:
- calibrate ESC's ?
- set the transmitter so all RC values in GUI are from 1000 to 2000 (+/- 20). Centre should be at 1500 (+/- 5) ?
- is your #define MAXTHROTTLE at 1800 or higher (try 2000).
A few other, though less likely, possibilities.
- make sure baro is OFF for your test (you should not be able to arm, when baro is on).
- are your vibrations reasonably low ? ( but that should already show up immediately, not after a few minutes).
first thought is weak battery, but I assume that would have crossed your mind already, and it wouldn't fly on KK as well....
The 2560 boards are not really different from pro mini in setup
These might be obvious, but did you:
- calibrate ESC's ?
- set the transmitter so all RC values in GUI are from 1000 to 2000 (+/- 20). Centre should be at 1500 (+/- 5) ?
- is your #define MAXTHROTTLE at 1800 or higher (try 2000).
A few other, though less likely, possibilities.
- make sure baro is OFF for your test (you should not be able to arm, when baro is on).
- are your vibrations reasonably low ? ( but that should already show up immediately, not after a few minutes).
Re: Hexcopter/quadcopter losing throttle power after awhile
hi thanks for your reply!
nope wasn't a weak battery, i thought so too but it was on a fully charged battery (i had my battery voltage checker/alarm on it and made sure)
yup i have calibrated my escs again, no difference
i'm using a turnigy 9x transmitter, the values don't reach 1000 and 2000, more like 1050 and 1950 but i think that should suffice.
my maxthrottle is at the default (which i think is 1800 or 1850)
baro is confirmed to be off
vibrations are reasonably low
i think the problem here is that everything is fine for at least the first 10-20 seconds. i can lift off at a little over half throttle and pushing to full throttle gets the copter accelerating upwards. but when the problem starts, the copter starts to descend even at full throttle which i find really odd
nope wasn't a weak battery, i thought so too but it was on a fully charged battery (i had my battery voltage checker/alarm on it and made sure)
yup i have calibrated my escs again, no difference
i'm using a turnigy 9x transmitter, the values don't reach 1000 and 2000, more like 1050 and 1950 but i think that should suffice.
my maxthrottle is at the default (which i think is 1800 or 1850)
baro is confirmed to be off
vibrations are reasonably low
i think the problem here is that everything is fine for at least the first 10-20 seconds. i can lift off at a little over half throttle and pushing to full throttle gets the copter accelerating upwards. but when the problem starts, the copter starts to descend even at full throttle which i find really odd
Re: Hexcopter/quadcopter losing throttle power after awhile
OK....
1050 .. 1950 should be fine.... however, the lower the full throttle, the lower the motor power will be, but 1950 should be plenty.
I would still give it a try at 2000 maxthrottle, made a significant difference for me.
Did you check in MultiWiiCconf (gui), under the settings tab, if everything is correct there ?
before it starts to decent (while flying OK), what motor outputs do you get ?
did you try to enable / disable #define MEGA_HW_PWM_SERVOS ? Not sure if it will make a difference, but I'm out of ideas otherwise....
A few things you could try.
do your motors spin up properly when directly connected to a receiver, i.e. ESC plugged directly into the receiver, without the multiwii connected (but still using 1000 - 2000 throttle channel output) ?
1500-1700 should be more than enough to lift a quad/hex/anything.... at 2000 it should run flat out.
At approx what throttle position would it hover when using the KK2 ?
if it doesn't fly while at 1500-1700 us, then I'm starting to doubt if the ESC calibration is really performed succesful, hence the test directly from receiver.
How did you perform the ESC calibration ?, from MW, or using receiver (and at which endpoints on 9X ?)
These are the things I can think off....
If all else fails, you might want to get a fresh download of MW, and ONLY configure the basics (without baro, mag, GPS, etc). Just set your copter type, sensor board, and PPM receiver (if used) and try from there ......
1050 .. 1950 should be fine.... however, the lower the full throttle, the lower the motor power will be, but 1950 should be plenty.
I would still give it a try at 2000 maxthrottle, made a significant difference for me.
Did you check in MultiWiiCconf (gui), under the settings tab, if everything is correct there ?
before it starts to decent (while flying OK), what motor outputs do you get ?
did you try to enable / disable #define MEGA_HW_PWM_SERVOS ? Not sure if it will make a difference, but I'm out of ideas otherwise....
A few things you could try.
do your motors spin up properly when directly connected to a receiver, i.e. ESC plugged directly into the receiver, without the multiwii connected (but still using 1000 - 2000 throttle channel output) ?
1500-1700 should be more than enough to lift a quad/hex/anything.... at 2000 it should run flat out.
At approx what throttle position would it hover when using the KK2 ?
if it doesn't fly while at 1500-1700 us, then I'm starting to doubt if the ESC calibration is really performed succesful, hence the test directly from receiver.
How did you perform the ESC calibration ?, from MW, or using receiver (and at which endpoints on 9X ?)
These are the things I can think off....
If all else fails, you might want to get a fresh download of MW, and ONLY configure the basics (without baro, mag, GPS, etc). Just set your copter type, sensor board, and PPM receiver (if used) and try from there ......
Re: Hexcopter/quadcopter losing throttle power after awhile
one more thing.....
please try an eprom_clear. there have been a lot of instances, where strange behaviour was resolved after clearing the eprom....
Not trying to be rude, but is your battery really up to the task ?
I ask because you wrote you checked it with a voltage checker, but was that during flight, or after it landed ?
a weak battery might sag under load, and show good voltage again after you stop.
If it flies fine, using the same battery, on KK2, that would rule it out also, but that's not clear from your replies....
The behaviour you describe really sounds like weak battery, thats why I ask again to be 100% sure.
please try an eprom_clear. there have been a lot of instances, where strange behaviour was resolved after clearing the eprom....
Not trying to be rude, but is your battery really up to the task ?
I ask because you wrote you checked it with a voltage checker, but was that during flight, or after it landed ?
a weak battery might sag under load, and show good voltage again after you stop.
If it flies fine, using the same battery, on KK2, that would rule it out also, but that's not clear from your replies....
The behaviour you describe really sounds like weak battery, thats why I ask again to be 100% sure.
Re: Hexcopter/quadcopter losing throttle power after awhile
hi thanks for the long reply! really detailed
i will try to put 2000 max throttle tomorrow, but currently i dont think it'll affect anything if it flies fine for the first half a minute or so. the settings are all correct, i can get it to fly from anything from 10 seconds to more than a minute before it starts to descend
i get somewhere around the same motor outputs. they jump around alot and my girlfriend was the one reading out the motor outputs but they all seem to be in the 1500-1700 range.
have not tried #define MEGA_HW_PWM_SERVOS but if all else fails maybe i'll try that..
yup all motors spin up properly... i previously used megapirate (kk2 was my friend's quad) it hovered around 60% throttle. esc calibration's ok as far as i know (if not it wouldnt be flying properly at first)
esc calibration performed from receiver, at my current endpoints of 9x (1050 and 1950, cant rmbr the exact percentage. probably 120%)
actually am planning to try mw2.3 again tomorrow without anything, see if it works. currently the only thing active other than the gyro/acc is the gps. i dont use the baro at all (cause i was suspecting it was causing the problem)
how do i do an eprom_clear? that sounds useful to do to be honest
no worries, battery is up to the task, i have flown with it previously many times. i checked it after it landed (cant check it during flight) but from my experience a weak battery will cause the low voltage alarm to go off if the voltage sags too far below (my alarm is set to go off at 3.5V) but anyway for reference i'm using a turnigy nano-tech 4000mah 3s 35c battery and the battery comes down cool/mildly warm (unlike if i push it too hard e.g. full throttling alot to make it climb quickly)
i will try to put 2000 max throttle tomorrow, but currently i dont think it'll affect anything if it flies fine for the first half a minute or so. the settings are all correct, i can get it to fly from anything from 10 seconds to more than a minute before it starts to descend
i get somewhere around the same motor outputs. they jump around alot and my girlfriend was the one reading out the motor outputs but they all seem to be in the 1500-1700 range.
have not tried #define MEGA_HW_PWM_SERVOS but if all else fails maybe i'll try that..
yup all motors spin up properly... i previously used megapirate (kk2 was my friend's quad) it hovered around 60% throttle. esc calibration's ok as far as i know (if not it wouldnt be flying properly at first)
esc calibration performed from receiver, at my current endpoints of 9x (1050 and 1950, cant rmbr the exact percentage. probably 120%)
actually am planning to try mw2.3 again tomorrow without anything, see if it works. currently the only thing active other than the gyro/acc is the gps. i dont use the baro at all (cause i was suspecting it was causing the problem)
how do i do an eprom_clear? that sounds useful to do to be honest
no worries, battery is up to the task, i have flown with it previously many times. i checked it after it landed (cant check it during flight) but from my experience a weak battery will cause the low voltage alarm to go off if the voltage sags too far below (my alarm is set to go off at 3.5V) but anyway for reference i'm using a turnigy nano-tech 4000mah 3s 35c battery and the battery comes down cool/mildly warm (unlike if i push it too hard e.g. full throttling alot to make it climb quickly)
Re: Hexcopter/quadcopter losing throttle power after awhile
Hmmmm.... very strange....
eprom_clear is a program in arduino.
you select it from file / examples / eprom / eprom_clear
then you simply compile and download it to your controller (make sure you have your board type and com port set correctly).... after download, it will just take a few seconds to clear the eprom.
After that is done, download your multiwii software again, and it should come up with default settings. Adjust where needed and fly again.
You really got me puzzled what might be causing this.... perhaps someone else has an idea ?
Regarding the ESC calibration. you're right, if calibration is far-off, it wouldn't fly from the beginning. But I'm thinking, perhaps they are calibrated such that they will only reach full power at (let's say) 2200 us. MW will never output anything over 2000 (or 1800, or whatever you set in maxtrottle). so it MIGHT be just enough when the battery is still fully charged, but as it drains, and the voltage drops slightly, it might start to come down.
Do the motors reach full rpm (same as when testing on the receiver, one by one), after you arm your copter, and (while holding it firmly), give it a rapid full throttle ? (beware you fingers !!!).
What board did you set in arduino ? It should be set as 'arduino mega 2560 or mega ADK'. Other boards might seem to work, but could possibly cause timing issues.
please keep us informed if you find anything....
eprom_clear is a program in arduino.
you select it from file / examples / eprom / eprom_clear
then you simply compile and download it to your controller (make sure you have your board type and com port set correctly).... after download, it will just take a few seconds to clear the eprom.
After that is done, download your multiwii software again, and it should come up with default settings. Adjust where needed and fly again.
You really got me puzzled what might be causing this.... perhaps someone else has an idea ?
Regarding the ESC calibration. you're right, if calibration is far-off, it wouldn't fly from the beginning. But I'm thinking, perhaps they are calibrated such that they will only reach full power at (let's say) 2200 us. MW will never output anything over 2000 (or 1800, or whatever you set in maxtrottle). so it MIGHT be just enough when the battery is still fully charged, but as it drains, and the voltage drops slightly, it might start to come down.
Do the motors reach full rpm (same as when testing on the receiver, one by one), after you arm your copter, and (while holding it firmly), give it a rapid full throttle ? (beware you fingers !!!).
What board did you set in arduino ? It should be set as 'arduino mega 2560 or mega ADK'. Other boards might seem to work, but could possibly cause timing issues.
please keep us informed if you find anything....
Re: Hexcopter/quadcopter losing throttle power after awhile
alright so i just did an eprom_clear and flashed mw2.2 in and the hex works!! maybe when i went from 2.3 to 2.2, the eprom got messed up or something..
anyway so on 2.2 it works great, the problem's totally gone. same for my friend, he didnt need to clear his eprom though just flashing to 2.2 got his quad up and working.
board etc everything has been set correctly, i suspect this might be a bug with the atmega board/mw2.3/gps combination? i'm not too sure but i'm just glad it's working now and i'll probably stick to 2.2 till a later version works...
in the meantime the 2 problems i'm facing are 1) magnetic inteference from motors and 2) random yawing of the copter (like major yaw, i've had it do 180 degrees or more yaw, usually to the left) if anyone has any thing to chip in on these 2 items would really appreciate it!
anyway so on 2.2 it works great, the problem's totally gone. same for my friend, he didnt need to clear his eprom though just flashing to 2.2 got his quad up and working.
board etc everything has been set correctly, i suspect this might be a bug with the atmega board/mw2.3/gps combination? i'm not too sure but i'm just glad it's working now and i'll probably stick to 2.2 till a later version works...
in the meantime the 2 problems i'm facing are 1) magnetic inteference from motors and 2) random yawing of the copter (like major yaw, i've had it do 180 degrees or more yaw, usually to the left) if anyone has any thing to chip in on these 2 items would really appreciate it!
Re: Hexcopter/quadcopter losing throttle power after awhile
OK, good to here it is (at least partly) solved....
Magnetic interference is something we need to live with.... try to locate your compass as fat as possible away from wiring (esp high current motor / battery wires). I've put my compass on a little wooden stick, away from the rest. Sometimes a few cm's is all it takes to remove the problem.
More difficult though when the compass is part of the MW controller board.... Perhaps putting the entire board higher up might improve it.
If it is working on 2.2, there is no reason it wouldn't work on 2.3. MW 2.3 is a very stable version, so I would say give it a go.... I've used it since the day it was released (also ATmega with GPS, two different controller boards, two different GPS types 1x MTK / 1x ublox)
random yawing can come from the compass being affected by power wiring, but it may also be caused by too much yaw gain.... try reducing yaw P a lot (I had to reduce it by more than half). And leave compass off when testing.
Magnetic interference is something we need to live with.... try to locate your compass as fat as possible away from wiring (esp high current motor / battery wires). I've put my compass on a little wooden stick, away from the rest. Sometimes a few cm's is all it takes to remove the problem.
More difficult though when the compass is part of the MW controller board.... Perhaps putting the entire board higher up might improve it.
If it is working on 2.2, there is no reason it wouldn't work on 2.3. MW 2.3 is a very stable version, so I would say give it a go.... I've used it since the day it was released (also ATmega with GPS, two different controller boards, two different GPS types 1x MTK / 1x ublox)
random yawing can come from the compass being affected by power wiring, but it may also be caused by too much yaw gain.... try reducing yaw P a lot (I had to reduce it by more than half). And leave compass off when testing.
Re: Hexcopter/quadcopter losing throttle power after awhile
Once the power starts to drop noticeably land and disarm, arm again and see if the power has been restored.
By disarming and arming again it will clear internal flight data, so if its software related you should see the power restore (I think).
By disarming and arming again it will clear internal flight data, so if its software related you should see the power restore (I think).
Re: Hexcopter/quadcopter losing throttle power after awhile
I had a similar problem after I mis-connected some of the connections to the rx. It would not develop enough power in any mode to lift off. 
Checked everything, couldn't get it to work. Found this thread, cleared EEPROM, recalibrated ESCs, reloaded MultiWii, recalibrated accel and mag, and viola, it works!
Checked everything, couldn't get it to work. Found this thread, cleared EEPROM, recalibrated ESCs, reloaded MultiWii, recalibrated accel and mag, and viola, it works!
Re: Hexcopter/quadcopter losing throttle power after awhile
Exact same problem:
Throttle is seriously diminished after a few seconds of flight, with not enough power to fly.
It's not the battery, and I'm not using BARO mode
same issue on multiwii 2.1, 2.3, and 2.2. I tried clearing the EEPROM, with no effect. The only thing I haven't done is re-calibrated the ESCs, but I don't see how that could have any impact on the signal coming from the controller.
Does Multiwii have some kind of safety landing mode, where it will diminish power in case of some malfunction?
Throttle is seriously diminished after a few seconds of flight, with not enough power to fly.
It's not the battery, and I'm not using BARO mode
same issue on multiwii 2.1, 2.3, and 2.2. I tried clearing the EEPROM, with no effect. The only thing I haven't done is re-calibrated the ESCs, but I don't see how that could have any impact on the signal coming from the controller.
Does Multiwii have some kind of safety landing mode, where it will diminish power in case of some malfunction?
Re: Hexcopter/quadcopter losing throttle power after awhile
Alright, it might be the battery...
Ordered slightly higher capacity batteries with a much higher C rating. If those don't work, I'll be back here hoping for more hints
Ordered slightly higher capacity batteries with a much higher C rating. If those don't work, I'll be back here hoping for more hints
Re: Hexcopter/quadcopter losing throttle power after awhile
Florentin wrote:Alright, it might be the battery...
Ordered slightly higher capacity batteries with a much higher C rating. If those don't work, I'll be back here hoping for more hints
Do you have Ez-GUI on phone & either BT or 3DR links? You can do performance test under actual load using EZ-GUI. Fully charge battery & hover in still conditions. Hover should draw approx. 10A on a IKg quad with a 2.2AH 3 cell Lipo & run for approx. 6 minutes before low voltage alert (10.5V).
EZ-GUI will report the battery voltage. If voltage is dropping rapidly & you are not getting close to 6minutes then battery capacity is diminished. A Lipo degrades if run down repeatedly below 30% & even if treated correctly will only last approx. 200 Charge/discharge cycles before requiring replacement.
If battery checks out OK, then lack of power in my experience is usually caused by excessive vibrations. These vibrations are detected by the Gyro/ACC which tries to correct for them & cuts power. Get quality composite or CF props & accurately balance then mount on good quality prop adapters.