Warning #1: an issue has been found with Tower's Pause button which can cause the vehicle to fly to an old position if the vehicle has not sent a position update to Tower in some time.
Warning #2: Copter-3.3.2 fixes a bug found in Copter-3.3.1's desired climb rate initialisation which could lead to a sudden momentary drop when switching from Stabilize or Acro to AltHold, Loiter or PosHold.
Warning #3: Copter-3.3.2 fixes an issue found in Copter-3.3.1 which could lead to hard landings in RTL or AUTO if the WPNAV_SPEED_DN was set too high (i.e. >400 or 4m/s) and/or the WPNAV_ACCEL_Z was set too low (i.e. <100 or 1m/s/s).
Warning #4: a bug was found in Copter-3.3 which could cause a sudden crash if you abort a Take-off initiated from a ground station. Video description is here. The bug is fixed in Copter-3.3.1 so we recommend upgrading.
Note #1: AC3.3-rc8 corrected a long standing bug in the HDOP reporting. HDOP values will appear about 40% lower than previously but this does not actually mean the GPS position is better than before.
Note #2: if upgrading from AC3.2.1 the vehicle's accelerometer calibration needs to be done again.
Note #3: set SERIAL2_PROTOCOL to "3" and reboot the board to enable FrSky telemetry like in previous versions.
Note #4: the wiki will be updated over the next few weeks to explain how to use the new features
Copter-3.3.1 is available through the mission planner. The full list of changes vs AC3.2.1 can be see in the ReleaseNotes and below are the most recent changes since AC3.3.
Sadly this version (and all future versions) will not run on the APM2.x boards due to CPU speed, flash and RAM restrictions.
Changes from 3.3:
1) Bug fix to prevent potential crash if Follow-Me is used after an aborted takeoff
2) compiler upgraded to 4.9.3 (runs slightly faster than 4.7.2 which was used previously)
Changes from 3.3-rc11:
1) EKF recovers from pre-arm "Compass variance" failure if compasses are consistent
Changes from 3.3-rc10:
1) PreArm "Need 3D Fix" message replaced with detailed reason from EKF
Changes from 3.3-rc9
1) EKF improvements:
a) simpler optical flow takeoff check
2) Bug Fixes/Minor enhancements:
a) fix INS3_USE parameter eeprom location
b) fix SToRM32 serial protocol driver to work with recent versions
c) increase motor pwm->thrust conversion (aka MOT_THST_EXPO) to 0.65 (was 0.50)
d) Firmware version sent to GCS in AUTOPILOT_VERSION message
3) Safety:
a) pre-arm check of compass variance if arming in Loiter, PosHold, Guided
b) always check GPS before arming in Loiter (previously could be disabled if ARMING_CHECK=0)
c) sanity check locations received from GCS for follow-me, do-set-home, do-set-ROI
d) fix optical flow failsafe (was not always triggering LAND when optical flow failed)
e) failsafe RTL vs LAND decision based on hardcoded 5m from home check (previously used WPNAV_RADIUS parameter)
Thanks for your testing!
Replies
With 3.3.2 or 3.2.1 I didn't have the same problem.
No gps problem until armed and after 1 minute flight.
The cabling is not very good. It is better to have them tighten together to the platform, not spread in the air. Use braided shields to have proper cable runs.
To protect the GPS from the inferences can use aluminum foil glued below the GPS body(all the black lower body.
Thanks Randy and all the team for the hard work!
Many Thank's Randy for all you and your team esfford. :)
I have had a few near collisions with buildings in Loiter mode, as the GPS has a glitch. I took it out in a clear area to test for this and it did it there. I have included the log file, and you can see at about 5:10, several things go crazy with EKF readings. If you turn on "use map" you will see that it was nearly back to me in the south west corner of the flight, and it takes off to the north west for about 30 feet, then comes back. This is very disturbing and will keep me from using this system until we know what is causing it.
I also have noticed that if the temp is below 50 degrees, Pixhawk reports that it has bad accelerometer health and inconsistent compass, until I warm it, then I have to keep it powered or it starts this again. It seems to work fine at room temp, and I am calibrating it regularly.
This is on a new Pixhawk, with Copter V3.3.3-rc2
I hope these are known issues with a solution.
Thanks,
Rick
2016-02-20 12-11-22.bin
I bought a new uBlox GPS unit from 3DR and replaced the cables to it, and started completely over setting up with the latest firmware and I am still getting these temporary deviances in perceived position. This is terrifying in that it is very dangerous to me and anyone around me. It also does this while flying missions, so when it recovers from its problems, it gives up on the mission it is running and decides to land, so now I can't rely on it for anything. I seriously think this is a problem with the Pixhawk. This is on a real Pixhawk from 3DR, that is a replacement for the one that had a known defect, but couldn't be replaced until after that one destroyed my quad. Fortunately, nobody was hurt in that one. This is just as dangerous. Can Randy or someone please look at my data and tell me if I am right? Suggesting that I buy more new equipment is not really what I'm looking for with this issue, either.
Do you have a camera or video equipment near? Can you share a photo how your gps is attached? perhaps that helps.
Here is a picture and you can see it up on the 3DR tower. I have used this configuration for a long time without this issue.
These are all excellent suggestions that I will be following up on and implementing, but if you look at the logs, it is just chugging along smoothly, then it instantly drops many of its satellites, so its position appears to change. These interferences could affect things, but they are pretty constant, so I'm not sure it would suddenly see a lot of interference all at once. I will know more as I go through these steps, though. Thanks for the excellent suggestions.
I want to follow up on this, in regard to my Pixhawk having abrupt changes in course when in GPS modes. Based on analysis of logs and suggestions for different configuration and some shielding, it now has much better performance. The copter now has the 1.3GHz vtx antenna on the bottom, with foil shielding on the video signal lines and covering the single-board camera. The logs now still show drops in number of sats and peaks in HDOP that look similar in shape to before, but the numbers are better, so it doesn't seem affected by them. Number of sats was high of 13 with drops to 9, now highs of 15 with drops to 13. HDOP was normally .8 with spikes up to 1.2 and now levels out to under .7 with spikes up to a max of .8. Thanks to Andy, Derek, Vesselin, Ivan, Cala, and DG for the diagnostics and excellent suggestions. My confidence is much higher with this platform now. It takes a village...
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