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
M8N config
Sorry Leon, but the .ubx file didnt work out.
You need to save it as .txt (ublox ucenter , menu tools -> GNSS Configuration -> GNSS to file
please
Will do (once I get in to work ;) )
I agree that they vary in quality. I've had a very bad one and my current one (RCTimer) is excellent.
I suspect the drift is down to the velocity noise which is supposed to be worse on these units. I think well designed attennas make a difference here, but net is that with patchy coverage performance will be worse than some of the older units.
YMMV :)
I can corroborate good experience with the RCTimer M8N. In fact I just ordered a few more. cheers.
I've got two copters with them now. One is from HK, and the other is from readytoflyquads. The mini M8Nv2.
HK gets a few more sats, but I think that's due to the layout of my copter (650 vs 250).
Both have the same behavior. Great in the clear sky, but jumps around more than previous GPS when lower to the ground.
It's raining now, so probably not a good time to get a log.. But, I can certainly make one. I simply have to arm it outside and let it sit stationary, and we can see MP thinks it's drifting all over.
I'm not all that concerned, since it's ok high in the air. Maybe I'm expecting too much, and am unlucky that my flying/testing ground has a few trees.
I've had very good results with the M8N on both a copter (3.3 rc5) and a fixed wing (3.3.0). My quad loiters with (at max) a 50cm drift in any direction.
I have experienced the drift you describe above, but only when I've been inside or amongst tall buildings (both times the quad stationary and on the ground), but I attribute this to not having a clear view of the sky for the antenna.
Well, I should have been more clear in my description..
Or at least added, the copter is very still when it is up above the trees. I don't notice much drift at all. But, down among the trees with a patchy view of the sky, I still have over 15 satellites and a low HDOP, (below 2 with the old pre rc8 hdop numbers) but the copter drifts all over as I described.
The old copter with lea-6 didn't drift as much in the same location, with fewer sats and higher hdop.. Sparsely wooded.. Clear sky directly above, but trees nearby.. spaced apart enough to comfortably fly around them.
that is why a best design is to use 2 GPS devices and use 1 m8n and one lea-6 on the same vehicle.
As Randy stated an effort will apparently take place to minimize position adjustment when one GPS switches with an another dynamically. As of 'jumping' coordinate from same single GPS - it is a different issue, probably.
Now I think that is different.
I never tried to run an M8N near a tree or above a tree.
I always used M8N in the clear sky.
So, maybe what I have written before is no loger valid =P
-
260
-
261
-
262
-
263
-
264
of 558 Next