Warning #1: PX4/Pixhawk users upgrading from AC3.1.5 (or earlier) may need to re-do their compass and accelerometer calibration because AC3.2 also uses the backup compass and accels.  Pre-arm checks have been added to ensure this has been done.

Warning #2: on the APM2.x the logs must be downloaded using MAVlink instead of the terminal.

AC3.2-rc14 is now available for BetaTesters through the mission planner’s Beta Firmwares link.  The full release notes can be found in ReleaseNotes.txt and changes from -rc13 can be seen below.

     Feel free to raise issues found during testing on this discussion or in the new support section in the APM Forum.

     It’s a big release with “the onion” restructure and a bunch of new features (including these 57 closed items) so we need to re-test almost everything including all flight modes, all mission commands and all the new features.  Marco and I will be maintaining (and adding to) this testing list.  Issues reported will first be checked by Jonathan, Marco and I and then confirmed bugs/issues will be put on the github issues list (and then hopefully fixed).

     Thanks especially to the beta testers who put their copters at risk testing each release.  Enjoy!

Changes from 3.2-rc13
1) Safety Features:
     a) fail to arm if second gyro calibration fails (can be disabled with ARMING_CHECK)
2) Bug fixes:
    a) DCM-check to require one continuous second of bad heading before triggering LAND
    b) I2C bug that could lead to Pixhawk freezing up if I2C bus is noisy
    c) reset DCM and EKF gyro bias estimates after gyro calibration (DCM heading could drift after takeoff due to sudden change in gyro values)
    d) use primary GPS for LED status (instead of always using first GPS)

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Hi Randy,

Yes sir - disarmed and in stabilize.


Going to have to disagree with you here.

If I let my uBlox LEA-6 run for about 1/2 hour inside the house away from any windows, I can usually acquire around 12 - 14 sats in the afternoon on a good day here in southern Florida.

The HDOP is usually around 1.4 - 1.6 and the vehicle position is rock steady.

Also, if I go outside and run my rover with unobstructed view of the sky, I can usually acquire 12 - 14 sats with an HDOP approaching 1.2 on occasion in the afternoon.


TCIII ArduRover2 Developer


Since I am using U-Center, and not the MP connected to my Pixhawk which at boot up will send configuration parameters to the GPS, the reason for the data stream glitches, according to Craig Elder, is that the GPS is sending back unnecessary messages that are eliminated by the configuration parameters sent by the Pixhawk. The reduced number of required messages reduces the GPS transmission overhead thus eliminating the glitching.
However, that does not explain why you are seeing the glitches in the MP assuming that you have the M8Q/N connected to your Pixhawk and are using the MP to communicate with the Pixhawk over MavLink?
Could it be that the present GPS configuration parameters being sent to the M8 by the Pixhawk firmware are not correct for eliminating superfluous messages?
Tom C ArduRover2 Developer

Thanks Randy,

with the help of that nice USB port I was able to connect and also booting up pixhawk at the same time. In Ucenter I recognized that the port was still set to SPI and also that the small lock was locked. I guess "you" didn't have a chance to change settings for the very first time. I set it to UART1 manually, unlocked the lock and safed settings. (Baudrate still at 9600)

I disconnected every power source, reconnected, booted up pixhawk and tada your values had been sent. Now baudrate is at 38400 as expected. Also rate settings to 5hz.

Could sb confirm this? pls make a backup of the settings so you could repeat that procedure.

It looks like I missed setting one configuration parameter that controls the messages sent by the GPS.
If you are using U-Center, you need to go to the Message View/MSG(Messages) and set UART1 On with a check in the box between "UART1" and "On" and put a 1 in the box to the right of "On"
I found this Message parameter setting in the 3DR LEA-6 configuration file.
The data stream appears to be pretty stable now in U-Center.
By the way, U-Center does not appear to convert UBX transmissions as far as HDOP and the number of sats.
Tom C ArduRover2 Developer


I think that you can change the Mask parameter, which is 5 deg presently, instead of shielding the antenna from "low elevation satellites".


TCIII ArduRover2 Developer

Hi Guys,

Great work on 3.2.

Upgraded my APM dji 450 'beater' from 3.1.x to 3.2 beta 2 last night and took it for a spin.

Need some help analyzing the attached log.

- stab, ok - stick response seemed a bit more lively / robotic than before but good

- alt hold - worked as well as before

- loiter - better than before

- hybrid - love it (but read on...)

YAW response was a bit slow - boosting the following parameters helped


ATC_RATE_Y_MAX = 72000

HYBRID mode - so here's where things get interesting...

- While flying fast (55km/h by OSD) in HYBRID mode I noticed the altitude decreasing - also noticed the throttle out was max'ed (100% by OSD).

- I increased the throttle and reduced forward pitch - the quad slowed down but kept descending.

- Pushed the throttle stick to 100% but it made no difference - could see throttle out actually FALLING (< 40% by OSD) !

- Just before it went down the forward speed was almost gone < 2 km/h and throttle out seemed to start to increase ( > 60% by OSD) but it was too late.

Recovered the quad undamaged. Checked the battery, more than 60% capacity remaining.

Test flew in stab, alt-hold and, loiter with the same battery - everything ok.

It seems as if the quad either ignored or had a severely delayed reaction to my increased throttle input as it slowed down.

Could this have something to do with HYBRID mode's braking phase?

Any insight appreciated. Thanks,

- Rob

Its not only me you disagree with! Show me a screen grab of the vehicle position over time, or send me a tlog. Your vehicle will be sationary, but the bread crumbs will show it moving all over the place.

Unless you have a clear view of the sky, GPS can be inaccurate. HDOP is indicative. Its not an absolute truth.

@christian, that is very interesting pixhawk updates the config of Neo-M8N at boot up as per the params set in the file AP_GPS_UBLOX.cpp file. so a separate utility is not required to configure the GPS. there is a good news. a clone of Neo-M8N GPS + compass is now available from Hobbyking for $32.00. since all the chips are from OEM so i think it should be reliable.


i have already ordered one. could not resist trying this new GPS on AC3.2-rc2. since the copter is now quite well tuned for AC3.2 so is right time to try this new GPS

Ravi: Hobby King offers a NEO-M7 module (Not M8) with a 2mm GPS patch antenna, which is not designed for GLONASS. Still no miracles around ;-)



HDOP says nothing about the accuracy in case of having reflections or Multi-Path reception.


HDOP is only based on the position of the satellites received which determines how accurately you can in theory calculate the position if and only if the received signal is perfect. HDOP is not impacted by reflections, but the GPS accuracy definitely is.


The effect is the following:

- HDOP bad means that: the GPS position estimate is likely to be bad since the received satellites are in a non-optimal position.

- HDOP good means that: the position estimate can be good based on the satellites received if the signal is not disturbed in the atmosphere and not reflected of buildings etc. HDOP will not indicate this at all.


So a low HDOP indication while being in a very urban area or inside a building means nothing. Indeed typically the estimated position will be wandering all over the place.


well the description in the hobbyking site does says it can rcv from GLONASS satellites.

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