GPS Hold issues

Droider

Drone Enthusiast
So been flying loads this weekend.. doing the flight school over and over.
BUT.. when I have GPS hold and Alt hold on for the best part of the flight towards the end of the battery, and I need to check at what voltage, the GPS hold starts going haywire.
The MK seems to jump from one location to another not a steady drift as at the beginning of the flight..

Ay ideas?
 

RTRyder

Merlin of Multirotors
So been flying loads this weekend.. doing the flight school over and over.
BUT.. when I have GPS hold and Alt hold on for the best part of the flight towards the end of the battery, and I need to check at what voltage, the GPS hold starts going haywire.
The MK seems to jump from one location to another not a steady drift as at the beginning of the flight..

Ay ideas?

You got me on this one, I've never had mine do anything like that, but then again I rarely if ever let the batts get to less than about 35% charge so maybe it does get wonky on low voltage. What voltage are your packs at when this happens, or how many mAh are you putting back in after a flight ?

Ken
 

Bartman

Welcome to MultiRotorForums.com!!
daveit might be unrelated to your problem but check the security of the 6 wire cable from the FC to the navi board. mine has vibrated loose twice and now has a quik tie holding it in place.off for the night....back tomorrowbart
 

Crash

Defies Psychics
So been flying loads this weekend.. doing the flight school over and over.
BUT.. when I have GPS hold and Alt hold on for the best part of the flight towards the end of the battery, and I need to check at what voltage, the GPS hold starts going haywire.
The MK seems to jump from one location to another not a steady drift as at the beginning of the flight..

Ay ideas?

The GPS in consumer products is not that accurate. What accuracy do you expect? Feet? Meters?

Reality is that it will be accurate to 15 feet either way most of the time. Below is an MK when sitting on a table.
View attachment 146

Maybe there's something else going on, but the first thing to check would be what the GPS is telling the bird to do.
 

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Droider

Drone Enthusiast
Thanks for the input. There is a definite change toward the end of the flight. Like the battery power is maybe not enough for the GPS / Nav board to do the calculations quick enough... I will analyse the flight log and see how many satellites it has lock on when it starts.. Ill also try and film it.
Typical flying weather is prefect this morning, not a cloud, or a whisper of wind.. frost covering the ground.. GGGrrrrrr I have to go to work!
 

Crash

Defies Psychics
I don't think low battery would do it. The bird will loose power to the motors well before the processors that run at 5V shut down.

Below is a procedure I posted at mk.us to access the GPS unit on an MK. Maybe it will help you see what's happening.
BTW, It works with the older firmware but I have not tried with the latest updates.

Download and install U-Center from here:
http://www.u-blox.com/en/evaluation-tools-a-software/u-center/u-center.html

Make a connection to MK with MK-Tool.
Open MKGPS screen
Hold Alt while clicking exit. This puts GPS in debug mode.
Close Mk-Tool

Open U-Center
Click Receiver - Port - Pick correct com port.
Click Baud Rate - Pick 57600
 

Droider

Drone Enthusiast
Thanks Crash... how would we ever survive with out the global knowledge the internet provides.. Ill check it out ASAP but work at the moment is manic so Ill keep you posted on how I get on with it

Thanks again

Dave
 

Droider

Drone Enthusiast
So here we have it. about six mins in and the bird is all over the place.. It nearly barrel rolled at one point..

This is a video of it happening..

 
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Bartman

Welcome to MultiRotorForums.com!!
Dave,
do you have an extra channel with a slider or knob of some sort that you can assign GPS gain to? doing so allows you to adjust the gain during the flight and I've found it to be extremely helpful for adjusting the GPS to different wind conditions during a flight. the motion your multi-rotor is making looks like the toilet-bowl syndrome that guys mention sometimes and i've seen it myself with mine when i change altitudes and get changing wind patterns. being able to adjust the GPS gain usually solves the problem.
Bart
 


Bartman

Welcome to MultiRotorForums.com!!
in MK Tool assign a POTI to GPS gain (I think its under NAVI 2 maybe?) and then a channel to the POTI you used. the channel on your transmitter needs to have a slider or knob to be able to adjust it and start the flight with it about 2/3 of max and then adjust it up or down to see if things improve.
give it a go and see if it helps.
bart
 

Droider

Drone Enthusiast
For some reason after 5 and a half mins in to the flight the wobbles occur, no matter what the wind is doing. After stepping back and checking my flight log I discovered what is causing the wobbles. The micro SD card. With out it plugged in I can fly the whole pack as stable as I think you can get in both GPS hold and ALT hold 10 mins approx.

As soon as I plug in the micro SD card the problem re occurs at around 5 and a half mins in to the flight. I have not tried a different sd card yet but it may be that the cheapo 64mb ex-phone sd card cannot keep up with the data stream.. any thoughts?
 

Crash

Defies Psychics
For some reason after 5 and a half mins in to the flight the wobbles occur, no matter what the wind is doing. After stepping back and checking my flight log I discovered what is causing the wobbles. The micro SD card. With out it plugged in I can fly the whole pack as stable as I think you can get in both GPS hold and ALT hold 10 mins approx.

As soon as I plug in the micro SD card the problem re occurs at around 5 and a half mins in to the flight. I have not tried a different sd card yet but it may be that the cheapo 64mb ex-phone sd card cannot keep up with the data stream.. any thoughts?

That is pretty interesting. This is a problem that I would post on the .de international forum to get Holger's attention. It appears to be a bug or bad programming that they need to fix in the navi code. There is no way that writing a log entry should interfere with flight. Please double check though and make sure the problem is repeatable.

Cheap SD cards are typically counterfeit, fake, defective or relabeled. But that's the new ones. I don't know if the Chinese were also screwing with the 64mb cards. But I would not bet against it.

There is software that can check the cards. I believe it's on this site somewhere: http://www.chucklohr.com/808/
 

Droider

Drone Enthusiast
Hi Crash

I am working away on mobile broadband so loads of cruising on thr tinternet is not a great option.. All I can say is it was a micro SD card that came with a Nokia N70 mobile phone. IT DOES HAPPEN ONLY when I have the card plugged in.. I am not a subscriber to wiki.de site other wise I would spend more time surfing than flying! I would love to have the time but unfortunately I dont and I find this forum the best for concentrated feed back and can keep track of the posts where other sites have to much traffic for me to keep up with...
 

Crash

Defies Psychics
Hi Crash

I am working away on mobile broadband so loads of cruising on thr tinternet is not a great option.. All I can say is it was a micro SD card that came with a Nokia N70 mobile phone. IT DOES HAPPEN ONLY when I have the card plugged in.. I am not a subscriber to wiki.de site other wise I would spend more time surfing than flying! I would love to have the time but unfortunately I dont and I find this forum the best for concentrated feed back and can keep track of the posts where other sites have to much traffic for me to keep up with...

The .de forum is the only place that the developers of the navi code will learn of the problem and fix it. I would make a post but it's second hand info. They would want to hear it from the horse's mouth and maybe even inspect the card. Or maybe you can email your MK supplier so they can contact Germany.


Here's info to check cards: http://sosfakeflash.wordpress.com/2...standard-in-detecting-usb-counterfeit-drives/
 
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Droider

Drone Enthusiast
The .de forum is the only place that the developers of the navi code will learn of the problem and fix it. I would make a post but it's second hand info. They would want to hear it from the horse's mouth and maybe even inspect the card. Or maybe you can email your MK supplier so they can contact Germany.


Here's info to check cards: http://sosfakeflash.wordpress.com/2...standard-in-detecting-usb-counterfeit-drives/

Crash.. can you link me to the relevant MK forum and Ill post it up... weather pants here today for flying. I could not find the app for checking the card but I will go buy a new one today and test it.
 


Droider

Drone Enthusiast
Ta.. will post up tomorrow.. had a bummer day with high wind and poor weather.. been to recce some places for tomorrow if the weather is good, otherwise Ill be sat on forums again!
 

zorba

Member
I just tested mine. Here are the results....


Warning: Only 3813 of 3815 MByte tested.
Test finished without errors.
You can now delete the test files *.h2w or verify them again.
Writing speed: 10.1 MByte/s
Reading speed: 21.9 MByte/s
H2testw v1.4
 

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