I have an original 3DR Pixhawk. I have been wondering for a while what am I doing wrong or are my expectations just misplaced with regard to getting help. If I face an issue what is the correct approach I should take to get support?
This is by no means a rant or any criticism of the level of support provided here. I just want to make sure that I am asking in the right place.
The reason I ask is because I have started a number of threads (questions) here but I hardly ever get any responses. Now I understand completely that as this is an open forum, no one is obligated to respond or provide help. So does that mean for every issue I should ideally raise a support ticket with 3DR?
What is the recommended and most efficient approach to getting help with an original 3DR pixhawk or APM for that matter?
Since you paid a premium for your hawk then yes open a ticket with 3DR. If "I" paid 200 dollars for a 100 dollar hawk I know "I'D" raise every issue no matter how trivial with the vendor as to me that is one of the reasons I would have even considered paying twice as much for a hawk.
Other resources do exist such as RCGroups which have a number of threads devoted to Hawks [not just 3DR hawks] and are quite active.
That said what "issues" are you having and please list them all here as these forums are really poor at being able to find or follow anything on.
Thanks for replying Craig.
Firstly my Config:
1. 650 Quad CF Frame
2. RotorGeeks 30A ESC BLHELI
3. 3DR Pixhawk & Wireless Telemetry
4. SunnySky 3108 720KV
5. DroTek M8N XL with Mag with the Ground plane provided by Drotek. (Wire soldered from Compass GND to Ground plane)
I'll list here the 4 issues I am facing:
1. Sometimes after a few good flights when I attempt a takeoff in stabilise I can see 2 motors visibly turning much slower than the other two. In this situation when if I proceed with the takeoff it always causes a flip. Also, when this happens the HUD also shows that the copter is not horizontal to the horizon. In reality the copter is on a perfectly flat and true surface. After having lost a number of props and damaged a GPS due to trial and error I eventually realised that I when I notice this behavior I need to abort the takeoff and perform an ACCEL calibration. This ALWAYS fixes the issue. Just to be safe I now perform an ACCEL calibration for every FIRST flight of the day. This approach has fixed the issue but I was never able to identify the root cause.
2. Performing a Compass Calibration does not work for me over wireless. Not I have the original 3DR Telemetry TX RX V2 (in the case). Over WIFI firstly the UI is extremely slow to update. However the main issue is that the points generated when I rotate the copter create a sphere at the extreme end of the RED axis as opposed to the center (intersection) of all the axis. As a result of this, I never catch 90% of the white dots and the Auto accept never occurs. Through trial and error I figured out that on a USB connection it works but still something strange happens.
Performing a compass calibration over USB initially (for the first 2 / 3) seconds behaves exactly the same as done over wireless. As in the points accumulate at the extreme end of one axis but then automatically they all reset to the center after a few seconds after which it works fine.
3. I have the Drotek M8N XL module with the ground plane soldered. The scatter graphs posted by CGS & by Thorsetn in this blog post Thorstens Blog show that with this exact same config I should get an x y scatter of just about 1M. However my x y scatter when I connect to ucenter is much higher.
4. Another question regarding the GPS whioch I posted to thorstens blog:
In order to fasten the ground plane to the alluminium mast I drilled a hole in round aluminium the base plate of the GPS Mast onto which the Drotek Ground plane is fastened using alluminium screws. The I soldered the GPS Ground to the Ground plane provided b yDrotek.
After doing these 2 things, very strangely I started getting offsets in excess of 600 on all 3 axis immediately after making this change. Assuming I had damaged the GPS module while soldering, I plugged another GPS in. (I had a spare same module) Once again I got similar offsets in excess of 500. This was all without the Main battery plugged in. Just powered using the mini USB cable so EMI shoukd not be an issue
Totally perplexed, I came to the conclusion that I had somehow magnetised the GPS mast baseplate during the drilling process. I unfastened the GPS leaving the wires connected and performed another calibration but this time by rotating only the GPS module in my hand. (Quad was stationary). The offsets I got were fantastic; all below 20.
What I have realed is the closer the actual GPS module is to the Ground plane; worse the offsets. Initially there was a gap of about 5mm between them and I was getting the horrible offsets. I have now increased the gap to about 20MM and I am back to 50's for the x & y axis and below 200 for the z axis. Any advise on this?
As Craig noted you might get answers over at RCGroups, might not. Sometimes your question may roll-off before the right person to answer comes along. Sometimes people get tired of answering the same questions over and over. Sometimes nobody knows.
As noted you paid for support so I would not be afraid to use it.
1. You should not have to recal the accelerometer.
2. Compass cal should work over the 3DR telemetry radios, I do it all the time.
3. Don't know.
4. Just to clarify the GPS has no offsets it is the compass. They are two different sensors and what you do to improve one might affect the other.
In general check to make sure you have no big power wires, like those that feed your ESC's near your flight controller. These big power wires can have magnetic fields which can interfere with your FC. You have something wrong in the problems in 1 and 2 and you either have a defective FC or you have interference problems or power problems. Many times people that complain about things working on USB but not battery have a power problem on battery. So check to make sure your voltage is clean and you are using a power module/ubec not power off an ESC bec.
1. Try checking the status pane of the HUD and see if the 2nd accel values are around 18000 (if so its a imu2 problem, which is fairly common).
2. Could be a reception issue, check the status link near the com/connect button and see what the link quality is.
3. That x/y scatter looks like mine does when I'm inside and there's something interfering with the GPS receiving. Is there something blocking the path to the sky or horizon?