Release 3.7.0, 9th September 2016

---------------------------------

The ArduPilot development team is proud to announce the release of

version 3.7.0 of APM:Plane. This is a major update so please read the

notes carefully.

The biggest changes in this release are:

- more reliable recovery from inverted flight

- automatic IC engine support

- Q_ASSIST_ANGLE for stall recovery on quadplanes

- Pixhawk2 IMU heater support

- PH2SLIM support

- AP_Module support

- Parrot Disco support

- major VRBrain support merge

- much faster boot time on Pixhawk

I'll give a bit of detail on each of these changes before giving the

more detailed list of changes.

More reliable recovery from inverted flight

Marc Merlin discovered that on some types of gliders that ArduPilot

would not reliably recover from inverted flight. The problem turned

out to be the use of the elevator at high bank angles preventing the

ailerons from fully recovering attitude. The fix in this release

prevent excessive elevator use when the aircraft is beyond

LIM_ROLL_CD. This should help a lot for people using ArduPilot as a

recovery system for manual FPV flight.

Automatic IC engine support

ArduPilot has supported internal combustion engines for a long time,

but until now the pilot has had to control the ignition and starter

manually using transmitter pass throughs. A new "ICE" module in

ArduPilot now allows for fully automatic internal combustion engine

support.

Coupled with an RPM sensor you can setup your aircraft to

automatically control the ignition and starter motor, allowing for one

touch start of the motor on the ground and automatic restart of the

motor in flight if needed.

The IC engine support is also integrated into the quadplane code,

allowing for automatic engine start at a specified altitude above the

ground. This is useful for tractor engine quadplanes where the

propeller could strike the ground on takeoff. The engine can also be

automatically stopped in the final stage of a quadplane landing.

Q_ASSIST_ANGLE for stall recovery

Another new quadplane feature is automatic recovery from fixed wing

stall. Previously the VTOL motors would only provide assistance in

fixed wing modes when the aircraft airspeed dropped below

Q_ASSIST_SPEED. Some stalls can occur with higher airspeed however,

and this can result in the aircraft losing attitude control without

triggering a Q_ASSIST_SPEED recovery. A new parameter Q_ASSIST_ANGLE

allows for automatic assistance when attitude control is lost,

triggering when the attitude goes outside the defined roll and pitch

limits and is more than Q_ASSIST_ANGLE degrees from the desired

attitude. Many thanks to Iskess for the suggestion and good discussion

around this feature.

Pixhawk2 heated IMU support

This release adds support for the IMU heater in the upcoming Pixhawk2,

allowing for more stable IMU temperatures. The Pixhawk2 is

automatically detected and the heater enabled at boot, with the target

IMU temperature controllable via BRD_IMU_TARGTEMP.

Using an IMU heater should improve IMU stability in environments with

significant temperature changes.

PH2SLIM Support

This release adds support for the PH2SLIM variant of the Pixhawk2,

which is a Pixhawk2 cube without the isolated sensor top board. This

makes for a very compact autopilot for small aircraft. To enable

PH2SLIM support set the BRD_TYPE parameter to 6 using a GCS connected

on USB.

AP_Module Support

This is the first release of ArduPilot with loadable module support

for Linux based boards. The AP_Module system allows for externally

compiled modules to access sensor data from ArduPilot controlled

sensors. The initial AP_Module support is aimed at vendors integrating

high-rate digital image stabilisation using IMU data, but it is

expected this will be expanded to other use cases in future releases.

Parrot Disco Support

This release adds support for the Parrot C.H.U.C.K autopilot in the

new Disco airframe. The Disco is a very lightweight flying wing with

a nicely integrated Linux based autopilot. The Disco flies very nicely

with ArduPilot, bringing the full set of mission capabilities of

ArduPilot to this airframe.

Major VRBrain Support Update

This release includes a major merge of support for the VRBrain family

of autopilots. Many thanks to the great work by Luke Mike in putting

together this merge!

Much Faster Boot Time

Boot times on Pixhawk are now much faster due to a restructuring of

the driver startup code, with slow starting drivers not started unless

they are enabled with the appropriate parameters. The restructuring

also allows for support of a wide variety of board types, including

the PH2SLIM above.

This release includes many other updates right across the flight

stack, including several new features. Some of the changes include:

- improved quadplane auto-landing

- limit roll and pitch by Q_ANGLE_MAX in Q modes

- improved ADSB avoidance and MAVLink streaming

- smoother throttle control on fixed-wing to VTOL transition

- removed "demo servos" movement on boot

- fixed a problem with spurious throttle output during boot (thanks

to Marco for finding this)

- support MAVLink SET_ATTITUDE_TARGET message

- log all rally points on startup

- fixed use of stick mixing for rudder with STICK_MIXING=0

- fixed incorrect tuning warnings when vtol not active

- support MAVLink based external GPS device

- support LED_CONTROL MAVLink message

- prevent baro update while disarmed for large height change

- support PLAY_TUNE MAVLink message

- added AP_Button support for remote button input reporting

- support Ping2020 ADSB transceiver

- fixed disarm by rudder in quadplanes

- support 16 channel SERVO_OUTPUT_RAW in MAVLink2

- added automatic internal combustion engine support

- support DO_ENGINE_CONTROL MAVLink message

- added ground throttle suppression for quadplanes

- added MAVLink reporting of logging subsystem health

- prevent motor startup on reboot in quadplanes

- added quadplane support for Advanced Failsafe

- added support for a 2nd throttle channel

- fixed bug in crash detection during auto-land flare

- lowered is_flying groundspeed threshold to 1.5m/s

- added support for new FrSky telemetry protocol varient

- added support for fence auto-enable on takeoff in quadplanes

- added Q_ASSIST_ANGLE for using quadplane to catch stalls in fixed wing flight

- added BRD_SAFETY_MASK to allow for channel movement for selected channels with safety on

- numerous improvements to multicopter stability control for quadplanes

- support X-Plane10 as SITL backend

- lots of HAL_Linux improvements to bus and thread handling

- fixed problem with elevator use at high roll angles that could

prevent attitude recovery from inverted flight

- improved yaw handling in EKF2 near ground

- added IMU heater support on Pixhawk2

- allow for faster accel bias learning in EKF2

- fixed in-flight yaw reset bug in EKF2

- added AP_Module support for loadable modules

- support Disco airframe from Parrot

- use full throttle in initial takeoff in TECS

- added NTF_LED_OVERRIDE support

- added terrain based simulation in SITL

- merged support for wide range of VRBrain boards

- added support for PH2SLIM and PHMINI boards with BRD_TYPE

- greatly reduced boot time on Pixhawk and similar boards

- fixed magic check for signing key in MAVLink2

- fixed averaging of gyros for EKF2 gyro bias estimate

Release 3.6.0, 6th June 2016

----------------------------

The ArduPilot development team is proud to announce the release of

version 3.6.0 of APM:Plane. This is a major update so please read the

notes carefully.

The biggest changes in this release are:

- major update to PX4Firmware code

- major update to QuadPlane code

- addition of MAVLink2 support

The updated PX4Firmware tree greatly improves support for the new

Pixracer boards as well as improving scheduling performance and UAVCAN

support.

The QuadPlane changes are very extensive in this release. A lot of new

features have been added, including:

- improved automatic weathervaning

- greatly improved support for mixed fixed wing and VTOL missions

- automatic RTL with VTOL land

- VTOL GUIDED mode support

- greatly improved transition code

- new tuning system for VTOL motors

- extensive upgrade to logging system for much better flight analysis

The new QuadPlane features are documented at:

http://ardupilot.org/plane/docs/quadplane-support.html

There is also a prototype implementation supporting tiltrotors and

tiltwings, but so far it has only been flown in simulations and it

should be considered very experimental.

Detailed changes include:

- added motortest for all quad motors in sequence

- merge upstream PX4Firmware changes

- new AC_AttitudeControl library from copter for quadplane

- modified default gains for quadplanes

- new velocity controller for initial quadplane landing

- smooth out final descent for VTOL landing

- changed default loop rate for quadplanes to 300Hz

- support up to 16 output channels (two via SBUS output only)

- fixed bug with landing flare for high values of LAND_FLARE_SEC

- improved crash detection logic

- added in-flight transmitter tuning

- fix handling of SET_HOME_POSITION

- added Q_VFWD_GAIN for forward motor in VTOL modes

- added Q_WVANE_GAIN for active weathervaning

- log the number of lost log messages

- Move position update to 50hz loop rather then the 10hz

- Suppress throttle when parachute release initiated, not after release.

- support Y6 frame class in quadplane

- log L1 xtrack error integrator and remove extra yaw logging

- limit roll before calculating load factor

- simplify landing flare logic

- smooth-out the end of takeoff pitch by reducing takeoff pitch min via TKOFF_PLIM_SEC

- added support for DO_VTOL_TRANSITION as a mission item

- fixed is_flying() for VTOL flight

- added Q_ENABLE=2 for starting AUTO in VTOL

- reload airspeed after VTOL landing

- lower default VTOL ANGLE_MAX to 30 degrees

- Change mode to RTL on end of mission rather then staying in auto

- implemented QRTL for quadplane RTL

- added Q_RTL_MODE parameter for QRTL after RTL approach

- reduced the rate of EKF and attitude logging to 25Hz

- added CHUTE_DELAY_MS parameter

- allow remapping of any input channel to any output channel

- numerous waf build improvements

- support fast timer capture for camera trigger feedback

- numerous improvements for Pixracer support

- added more general tiltrotor support to SITL

- only save learned compass offsets when disarmed

- support MISSION_ITEM_INT for more accurate waypoint positions

- change parachute deployment altitude to above ground not home

- added AP_Tuning system for QuadPlane tuning

- added initial support for tiltrotors and tiltwings

- added LOG_REPLAY and LOG_DISARMED parameters

- added Q_GUIDED_MODE parameter

- major update to QuadPlane documentation

- added MAVLink2 support

- fixed origin vs home altitude discrepancy

- improved Lidar based landing glide slope

- fixed throttle failsafe with THR_PASS_STAB=1

- prevent EKF blocking during baro and airspeed cal

- allow for ground testing of parachutes with CHUTE_MINALT=0

- fixed elevator stick mixing for above 50% input

- added QuadPlane ESC calibration

Release 3.6.0beta1, 30th April 2016

-----------------------------------

The ArduPilot development team is proud to announce the release of

version 3.6.0beta1 of APM:Plane. This is the first beta version of a

major release.

The biggest changes in this release is the major update of the

PX4Firmware tree which greatly improves support for the Pixracer

board, and a lot of QuadPlane improvements and new features.

Detailed changes include:

- added motortest for all quad motors in sequence

- merge upstream PX4Firmware changes

- new AC_AttitudeControl library from copter for quadplane

- modified default gains for quadplanes

- new velocity controller for initial quadplane landing

- smooth out final descent for VTOL landing

- changed default loop rate for quadplanes to 300Hz

- support up to 16 output channels (two via SBUS output only)

- fixed bug with landing flare for high values of LAND_FLARE_SEC

- improved crash detection logic

- added in-flight transmitter tuning

- fix handling of SET_HOME_POSITION

- added Q_VFWD_GAIN for forward motor in VTOL modes

- added Q_WVANE_GAIN for active weathervaning

- log the number of lost log messages

- Move position update to 50hz loop rather then the 10hz

- Suppress throttle when parachute release initiated, not after release.

- support Y6 frame class in quadplane

- log L1 xtrack error integrator and remove extra yaw logging

- limit roll before calculating load factor

- simplify landing flare logic

- smooth-out the end of takeoff pitch by reducing takeoff pitch min via TKOFF_PLIM_SEC

- added support for DO_VTOL_TRANSITION as a mission item

- fixed is_flying() for VTOL flight

- added Q_ENABLE=2 for starting AUTO in VTOL

- reload airspeed after VTOL landing

- lower default VTOL ANGLE_MAX to 30 degrees

- Change mode to RTL on end of mission rather then staying in auto

- implemented QRTL for quadplane RTL

- added Q_RTL_MODE parameter for QRTL after RTL approach

- reduced the rate of EKF and attitude logging to 25Hz

- added CHUTE_DELAY_MS parameter

- allow remapping of any input channel to any output channel

- numerous waf build improvements

- support fast timer capture for camera trigger feedback

- numerous improvements for Pixracer support

- added more general tiltrotor support to SITL

Release 3.5.3, 30th April 2016

------------------------------

The ArduPilot development team is proud to announce the release of

version 3.5.3 of APM:Plane. This is a minor release with only small

bugfix changes.

The main motivation for the release is a problem with flying without a

compass enabled. If you fly 3.5.2 with MAG_ENABLE=0 or no compass

attached then there is a risk that the EKF2 attitude estimator may

become unstable before takeoff. This can cause the aircraft to crash.

The other changes in this release are:

- fixed loiter radius for counter-clockwise loiter

- fixed the loiter radius when doing a RTL at the end of a mission

- provide reasons to the GCS when a uBlox GPS fails to properly configure

- support a wider variety of NMEA GPS receivers

- use EKF1 by default if no compass is enabled

Happy flying!

Release 3.5.2, 26th March 2016

------------------------------

The ArduPilot development team is proud to announce the release of

version 3.5.2 of APM:Plane. This is a minor release with small

changes.

The main reason for this release over 3.5.1 is a fix for a bug where

the px4io co-processor on a Pixhawk can run out of memory while

booting. This causes the board to be unresponsive on boot. It only

happens if you have a more complex servo setup and is caused by too

much memory used by the IO failsafe mixer.

The second motivation for this release is to fix an issue where during

a geofence altitude failsafe that happens at low speed an aircraft may

dive much further than it should to gain speed. This only happened if

the thrust line of the aircraft combined with low pitch integrator

gain led to the aircraft not compensating sufficiently with elevator

at full throttle in a TECS underspeed state. To fix this two changes

have been made:

- a minimum level of integrator in the pitch controller has been

added. This level has a sufficiently small time constant to avoid

the problem with the TECS controller in an underspeed state.

- the underspeed state in TECS has been modified so that underspeed

can end before the full target altitude has been reached, as long

as the airspeed has risen sufficiently past the minimum airspeed

for a sufficient period of time (by 15% above minimum airspeed for

3 seconds).

The default P gains for both roll and pitch have also been raised from

0.4 to 0.6. This is to help for users that fly with the default

parameters. A value of 0.6 is safe for all aircraft that I have

analysed logs for.

The default gains and filter frequencies of the QuadPlane code have

also been adjusted to better reflect the types of aircraft users have

been building.

Other changes include:

- improved QuadPlane logging for better analysis and tuning (adding

RATE and QTUN messages)

- fixed a bug introduced in 3.5.1 in rangefinder landing

- added TECS logging of speed_weight and flags

- improvements to the lsm303d driver for Linux

- improvements to the waf build system

Release 3.5.1, 21st March 2016

------------------------------

The ArduPilot development team is proud to announce the release of

version 3.5.1 of APM:Plane. This is a minor release with primarily

small changes.

The changes in this release are:

- update uavcan to new protocol

- always exit loiter in AUTO towards next waypoint

- support more multicopter types in quadplane

- added support for reverse thrust landings

- added LAND_THR_SLEW parameter

- added LAND_THEN_NEUTRL parameter

- fixed reporting of armed state with safety switch

- added optional arming check for minimum voltage

- support motor test for quadplanes

- added QLAND flight mode (quadplane land mode)

- added TECS_LAND_SRC (land sink rate change)

- use throttle slew in quadplane transition

- added PID tuning for quadplane

- improved text message queueing to ground stations

- added LAND_THR_SLEW parameter

- re-organisation of HAL_Linux bus API

- improved NMEA parsing in GPS driver

- changed TECS_LAND_SPDWGT default to -1

- improved autoconfig of uBlox GPS driver

- support a wider range of Lightware serial Lidars

- improved non-GPS performance of EKF2

- allow for indoor flight of quadplanes

- improved compass fusion in EKF2

- improved support for Pixracer board

- improved NavIO2 support

- added BATT_WATT_MAX parameter

The reverse thrust landing is particularly exciting as that adds a

whole new range of possibilities for landing in restricted areas. Many

thanks to Tom for the great work on getting this done.

The uavcan change to the new protocol has been a long time coming, and

I'd like to thank Holger for both his great work on this and his

patience given how long it has taken to be in a release. This adds

support for automatic canbus node assignment which makes setup much

easier, and also supports the latest versions of the Zubax canbus GPS.

My apologies if your favourite feature didn't make it into this

release! There are a lot more changes pending but we needed to call a

halt for the release eventually. This release has had a lot of flight

testing and I'm confident it will be a great release.

Happy flying!

Release 3.5.0, 30th January 2016

--------------------------------

The ArduPilot development team is proud to announce the release of

version 3.5.0 of APM:Plane. This is a major release with a lot of

changes so please read the notes carefully!

The biggest changes in this release are:

- switch to new EKF2 kalman filter for attitude and position estimation

- added support for parachutes

- added support for QuadPlanes

- support for 4 new flight boards, the QualComm Flight, the BHAT,

the PXFmini and the Pixracer

- support for arming on moving platforms

- support for better camera trigger logging

New Kalman Filter

The 3.4 release series was the first where APM:Plane used a Kalman

Filter by default for attitude and position estimation. It works very

well, but Paul Riseborough has been working hard recently on a new

EKF variant which fixes many issues seen with the old estimator. The

key improvements are:

- support for separate filters on each IMU for multi-IMU boards

(such as the Pixhawk), giving a high degree of redundency

- much better handling of gyro drift estimation, especially on

startup

- much faster recovery from attitude estimation errors

After extensive testing of the new EKF code we decided to make it the

default for this release. You can still use the old EKF if you want to

by setting AHRS_EKF_TYPE to 1, although it is recommended that the new

EKF be used for all aircraft.

Parachute Support

This is the first release with support for parachute landings on

plane. The configuration and use of a parachute is the same as the

existing copter parachute support. See

http://copter.ardupilot.org/wiki/parachute/

Note that parachute support is considered experimental in planes.

QuadPlane Support

This release includes support for hybrid plane/multi-rotors called

QuadPlanes. More details are available in this blog post:

http://diydrones.com/profiles/blogs/quadplane-support-in-apm-plane-3-5-0

Support for 4 new Flight Boards

The porting of ArduPilot to more flight boards continues, with support

for 3 new flight boards in this release. They are:

- the BHAT board

- the PXFmini

- the QualComm Flight

- the Pixracer

More information about the list of supported boards is available here:

http://dev.ardupilot.org/wiki/supported-autopilot-controller-boards/

Startup on a moving platform

One of the benefits of the new EKF2 estimator is that it allows for

rapid estimation of gyro offset without doing a gyro calibration on

startup. This makes it possible to startup and arm on a moving

platform by setting the INS_GYR_CAL parameter to zero (to disable gyro

calibration on boot). This should be a big help when flying off boats.

Improved Camera Trigger Logging

This release adds new CAM_FEEDBACK_PIN and CAM_FEEDBACK_POL

parameters. These add support for separate CAM and TRIG log messages,

where TRIG is logged when the camera is triggered and the CAM message

is logged when an external pin indicates the camera has actually

fired. This pin is typically based on the flash hotshoe of a camera

and provides a way to log the exact time of camera triggering more

accurately. Many thanks to Dario Andres and Jaime Machuca for their

work on this feature.

That is just a taste of all of the improvements in this release. In

total the release includes over 1500 patches. Some of the other more

significant changes include:

- RPM logging

- new waf build system

- new async accel calibrator

- SITL support for quadplanes

- improved land approach logic

- better rangefinder power control

- ADSB adapter support

- dataflash over mavlink support

- settable main loop rate

- hideable parameters

- improved crash detection logic

- added optional smooth speed weighting for landing

- improved logging for dual-GPS setups

- improvements to multiple RTK GPS drivers

- numerous HAL_Linux improvements

- improved logging of CAM messages

- added support for IMU heaters in HAL_Linux

- support for RCInput over UDP in HAL_Linux

- improved EKF startup checks for GPS accuracy

- added raw IMU logging for all platforms

- added BRD_CAN_ENABLE parameter

- support FlightGear visualisation in SITL

- configurable RGB LED brightness

- added RTL_RADIUS parameter

- improvements to the OVERRIDE_CHAN handling, fixing a race condition

- added OVERRIDE_SAFETY parameter

Many thanks to everyone who contributed to this release! The

development team is growing at a fast pace, with 57 people

contributing changes over this release cycle.

I'd like to make special mention of Tom Pittenger and Michael du

Breuil who have been doing extensive testing of the plane development

code, and also contributing a great deal of their own

improvements. Thanks!

Release 3.4.0, 24th September 2015

----------------------------------

The ArduPilot development team is proud to announce the release of

version 3.4.0 of APM:Plane. This is a major release with a lot of

changes so please read the notes carefully!

First release with EKF by default

This is the also the first release that enables the EKF (Extended

Kalman Filter) for attitude and position estimation by default. This

has been in development for a long time, and significantly improves

flight performance. You can still disable the EKF if you want to using

the AHRS_EKF_USE parameter, but it is strongly recommended that you

use the EKF. Note that if an issue is discovered with the EKF in

flight it will automatically be disabled and the older DCM system will

be used instead. That should be very rare.

In order to use the EKF we need to be a bit more careful about the

setup of the aircraft. That is why in the last release we enabled

arming and pre-arm checks by default. Please don't disable the arming

checks, they are there for very good reasons.

Last release with APM1/APM2 support

This will be the last major release that supports the old APM1/APM2

AVR based boards. We have finally run out of flash space and

memory. In the last few releases we spent quite a bit of time trying

to squeeze more and more into the small flash space of the APM1/APM2,

but it had to end someday if ArduPilot is to continue to develop. I am

open to the idea of someone else volunteering to keep doing

development of APM1/APM2 so if you have the skills and inclination do

please get in touch. Otherwise I will only do small point release

changes for major bugs.

Even to get this release onto the APM1/APM2 we had to make sacrifices

in terms of functionality. The APM1/APM2 release is missing quite a

few features that are on the Pixhawk and other boards. For example:

- no rangefinder support for landing

- no terrain following

- no EKF support

- no camera control

- no CLI support

- no advanced failsafe support

- no HIL support (sorry!)

- support for far fewer GPS types

that is just the most obvious major features that are missing on

APM1/APM2. There are also numerous other smaller things where we need

to take shortcuts on the APM1/APM2. Some of these features were

available on older APM1/APM2 releases but needed to be removed to

allow us to squeeze the new release onto the board. So if you are

happy with a previous release on your APM2 and want a feature that is

in that older release and not in this one then perhaps you shouldn't

upgrade.

PID Tuning

While most people are happy with autotune to tune the PIDs for their

planes, it is nice also to be able to do fine tuning by hand. This

release includes new dataflash and mavlink messages to help with that

tuning. You can now see the individual contributions of the P, I and D

components of each PID in the logs, allowing you to get a much better

picture of the performance.

A simple application of this new tuning is you can easily see if your

trim is off. If the Pitch I term is constantly contributing a

signifcant positive factor then you know that ArduPilot is having to

constantly apply up elevator, which means your plane is nose

heavy. The same goes for roll, and can also be used to help tune your

ground steering.

Vibration Logging

This release includes a lot more options for diagnosing vibration

issues. You will notice new VIBRATION messages in MAVLink and VIBE

messages in the dataflash logs. Those give you a good idea of your

(unfiltered) vibration levels. For really detailed analysis you can

setup your LOG_BITMASK to include raw logging, which gives you every

accel and gyro sample on your Pixhawk. You can then do a FFT on the

result and plot the distribution of vibration level with

frequency. That is great for finding the cause of vibration

issues. Note that you need a very fast microSD card for that to work!

Rudder Disarm

This is the first release that allows you to disarm using the rudder

if you want to. It isn't enabled by default (due to the slight risk of

accidentially disarming while doing aerobatics). You can enable it

with the ARMING_RUDDER parameter by setting it to 2. It will only

allow you to disarm if the autopilot thinks you are not flying at the

time (thanks to the "is_flying" heuristics from Tom Pittenger).

More Sensors

This release includes support for a bunch more sensors. It now supports

3 different interfaces for the LightWare range of Lidars (serial, I2C

and analog), and also supports the very nice Septentrio RTK

dual-frequency GPS (the first dual-frequency GPS we have support

for). It also supports the new "blue label" Lidar from Pulsed Light

(both on I2C and PWM).

For the uBlox GPS, we now have a lot more configurability of the

driver, with the ability to set the GNSS mode for different

constellations. Also in the uBlox driver we support logging of the raw

carrier phase and pseudo range data, which allows for post-flight RTK

analysis with raw-capable receivers for really accurate photo

missions.

Better Linux support

This release includes a lot of improvements to the Linux based

autopilot boards, including the NavIO+, the PXF and ERLE boards and

the BBBMini and the new RasPilot board. If you like the idea of flying

with Linux then please try it out!

On-board compass calibrator

We also have a new on-board compass calibrator, which also adds calibration

for soft iron effects, allowing for much more accurate compass

calibration. Support for starting the compass calibration in the

various ground stations is still under development, but it looks like

this will be a big improvement to compass calibration.

Lots of other changes!

The above list is just a taste of the changes that have gone into this

release. Thousands of small changes have gone into this release with

dozens of people contributing. Many thanks to everyone who helped!

Other key changes include:

- fixed return point on geofence breach

- enable messages for MAVLink gimbal support

- use 64 bit timestamps in dataflash logs

- added realtime PID tuning messages and PID logging

- fixed a failure case for the px4 failsafe mixer

- added DSM binding support on Pixhawk

- added ALTITUDE_WAIT mission command

- added vibration level logging

- ignore low voltage failsafe while disarmed

- added delta velocity and delta angle logging

- fix LOITER_TO_ALT to verify headings towards waypoints within the loiter radius

- allow rudder disarm based on ARMING_RUDDER parameter

- fix default behaviour of flaps

- prevent mode switch changes changing WP tracking

- make TRAINING mode obey stall prevention roll limits

- disable TRIM_RC_AT_START by default

- fixed parameter documentation spelling errors

- send MISSION_ITEM_REACHED messages on waypoint completion

- fixed airspeed handling in SITL simulators

- enable EKF by default on plane

- Improve gyro bias learning rate for plane and rover

- Allow switching primary GPS instance with 1 sat difference

- added NSH over MAVLink support

- added support for mpu9250 on pixhawk and pixhawk2

- Add support for logging ublox RXM-RAWX messages

- lots of updates to improve support for Linux based boards

- added ORGN message in dataflash

- added support for new "blue label" Lidar

- switched to real hdop in uBlox driver

- improved auto-config of uBlox

- raise accel discrepancy arming threshold to 0.75

- improved support for tcp and udp connections on Linux

- switched to delta-velocity and delta-angles in DCM

- improved detection of which accel to use in EKF

- improved auto-detections of flow control on pixhawk UARTs

- Failsafe actions are not executed if already on final approach or land.

- Option to trigger GCS failsafe only in AUTO mode.

- added climb/descend parameter to CONTINUE_AND_CHANGE_ALT

- added HDOP to uavcan GPS driver

- improved sending of autopilot version

- prevent motor startup with bad throttle trim on reboot

- log zero rangefinder distance when unhealthy

- added PRU firmware files for BeagleBoneBlack port

- fix for recent STORM32 gimbal support

- changed sending of STATUSTEXT severity to use correct values

- added new RSSI library with PWM input support

- fixed MAVLink heading report for UAVCAN GPS

- support LightWare I2C rangefinder on Linux

- improved staging of parameters and formats on startup to dataflash

- added new on-board compass calibrator

- improved RCOutput code for NavIO port

- added support for Septentrio GPS receiver

- support DO_MOUNT_CONTROl via command-long interface

- added CAM_RELAY_ON parameter

- moved SKIP_GYRO_CAL functionality to INS_GYR_CAL

- added detection of bad lidar settings for landing

Note that the documentation hasn't yet caught up with all the changes

in this release. We are still working on that, but meanwhile if you

see a feature that interests you and it isn't documented yet then

please ask.

Release 3.3.0, 20th May 2015

----------------------------

The ardupilot development team is proud to announce the release of

version 3.3.0 of APM:Plane. This is a major release with a lot of

changes. Please read the release notes carefully!

The last stable release was 3 months ago, and since that time we have

applied over 1200 changes to the code. It has been a period of very

rapid development for ArduPilot. Explaining all of the changes that

have been made would take far too long, so I've chosen some key

changes to explain in detail, and listed the most important secondary

changes in a short form. Please ask for details if there is a change

you see listed that you want some more information on.

Arming Changes

--------------

This is the first release of APM:Plane where ARMING_CHECK and

ARMING_REQUIRE both default to enabled. That means when you upgrade if

you didn't previously have arming enabled you will need to learn about

arming your plane.

Please see this page for more information on arming:

http://plane.ardupilot.com/wiki/arming-your-plane/

I know many users will be tempted to disable the arming checks, but

please don't do that without careful thought. The arming checks are an

important part of ensuring the aircraft is ready to fly, and a common

cause of flight problems is to takeoff before ArduPilot is ready.

Re-do Accelerometer Calibration

-------------------------------

Due to a change in the maximum accelerometer range on the Pixhawk all

users must re-do their accelerometer calibration for this release. If

you don't then your plane will fail to arm with a message saying that

you have not calibrated the accelerometers.

Only 3D accel calibration

-------------------------

The old "1D" accelerometer calibration method has now been removed, so

you must use the 3D accelerometer calibration method. The old method

was removed because a significant number of users had poor flights due

to scaling and offset errors on their accelerometers when they used

the 1D method. My apologies for people with very large aircraft who

find the 3D method difficult.

Note that you can do the accelerometer calibration with the autopilot

outside the aircraft which can make things easier for large aircraft.

Auto-disarm

-----------

After an auto-landing the autopilot will now by default disarm after

LAND_DISARMDELAY seconds (with a default of 20 seconds). This feature

is to prevent the motor from spinning up unexpectedly on the ground

after a landing.

HIL_MODE parameter

------------------

It is now possible to configure your autopilot for hardware in the

loop simulation without loading a special firmware. Just set the

parameter HIL_MODE to 1 and this will enable HIL for any

autopilot. This is designed to make it easier for users to try HIL

without having to find a HIL firmware.

SITL on Windows

---------------

The SITL software in the loop simulation system has been completely

rewritten for this release. A major change is to make it possible to

run SITL on native windows without needing a Linux virtual

machine. There should be a release of MissionPlanner for Windows soon

which will make it easy to launch a SITL instance.

The SITL changes also include new backends, including the CRRCSim

flight simulator. This gives us a much wider range of aircraft we can

use for SITL. See http://dev.ardupilot.com/wiki/simulation-2/ for more

information.

Throttle control on takeoff

---------------------------

A number of users had problems with pitch control on auto-takeoff, and

with the aircraft exceeding its target speed during takeoff. The

auto-takeoff code has now been changed to use the normal TECS throttle

control which should solve this problem.

Rudder only support

-------------------

There is a new RUDDER_ONLY parameter for aircraft without ailerons,

where roll is controlled by the rudder. Please see the documentation

for more information on flying with a rudder only aircraft:

http://plane.ardupilot.com/wiki/arduplane-parameters/#rudder_only_aircraft_arduplanerudder_only

APM1/APM2 Support

-----------------

We have managed to keep support for the APM1 and APM2 in this release,

but in order to fit it in the limited flash space we had to disable

some more features when building for those boards. For this release

the AP_Mount code for controlling camera mounts is disabled on

APM1/APM2.

At some point soon it will become impractical to keep supporting the

APM1/APM2 for planes. Please consider moving to a 32 bit autopilot

soon if you are still using an APM1 or APM2.

New INS code

------------

There have been a lot of changes to the gyro and accelerometer

handling for this release. The accelerometer range on the Pixhawk has

been changed to 16g from 8g to prevent clipping on high vibration

aircraft, and the sampling rate on the lsm303d has been increased to

1600Hz.

An important bug has also been fixed which caused aliasing in the

sampling process from the accelerometers. That bug could cause

attitude errors in high vibration environments.

Numerous Landing Changes

------------------------

Once again there have been a lot of improvements to the automatic

landing support. Perhaps most important is the introduction of a

smooth transition from landing approach to the flare, which reduces

the tendency to pitch up too much on flare.

There is also a new parameter TECS_LAND_PMAX which controls the

maximum pitch during landing. This defaults to 10 degrees, but for

many aircraft a smaller value may be appropriate. Reduce it to 5

degrees if you find you still get too much pitch up during the flare.

Other secondary changes in this release include:

- a new SerialManager library which gives much more flexible management of serial port assignment

- changed the default FS_LONG_TIMEOUT to 5 seconds

- raised default IMAX for roll/pitch to 3000

- lowered default L1 navigation period to 20

- new BRD_SBUS_OUT parameter to enable SBUS output on Pixhawk

- large improvements to the internals of PX4Firmware/PX4NuttX for better performance

- auto-formatting of microSD cards if they can't be mounted on boot (PX4/Pixhawk only)

- a new PWM based driver for the PulsedLight Lidar to avoid issues with the I2C interface

- fixed throttle forcing to zero when disarmed

- only reset mission on disarm if not in AUTO mode

- much better handling of steep landings

- added smooth transition in landing flare

- added HIL_MODE parameter for HIL without a special firmware

- lowered default FS_LONG_TIMEOUT to 5 seconds

- mark old ELEVON_MIXING mode as deprecated

- fixed 50Hz MAVLink support

- support DO_SET_HOME MAVLink command

- fixed larger values of TKOFF_THR_DELAY

- allow PulsedLight Lidar to be disabled at a given height

- fixed bungee launch (long throttle delay)

- fixed a bug handling entering AUTO mode before we have GPS lock

- added CLI_ENABLED parameter

- removed 1D accel calibration

- added EKF_STATUS_REPORT MAVLink message

- added INITIAL_MODE parameter

- added TRIM_RC_AT_START parameter

- added auto-disarm after landing (LAND_DISARMDELAY)

- added LOCAL_POSITION_NED MAVLink message

- avoid triggering a fence breach in final stage of landing

- rebuild glide slope if we are above it and climbing

- use TECS to control throttle on takeoff

- added RUDDER_ONLY parameter to better support planes with no ailerons

- updated Piksi RTK GPS driver

- improved support for GPS data injection (for Piksi RTK GPS)

- added NAV_LOITER_TO_ALT mission item

- fixed landing approach without an airspeed sensor

- support RTL_AUTOLAND=2 for landing without coming to home first

- disabled camera mount support on APM1/APM2

- added support for SToRM32 and Alexmos camera gimbals

- added support for Jaimes mavlink enabled gimbal

- improved EKF default tuning for planes

- updated support for NavIO and NavIO+ boards

- updated support for VRBrain boards

- fixes for realtime threads on Linux

- added simulated sensor lag for baro and mag in SITL

- made it possible to build SITL for native Windows

- switched to faster accel sampling on Pixhawk

- added coning corrections on Pixhawk

- set ARMING_CHECK to 1 by default

- disable NMEA and SiRF GPS on APM1/APM2

- support MPU9255 IMU on Linux

- updates to BBBMINI port for Linux

- added TECS_LAND_PMAX parameter

- switched to synthetic clock in SITL

- support CRRCSim FDM backend in SITL

- new general purpose replay parsing code

- switched to 16g accel range in Pixhawk

- added FENCE_AUTOENABLE=2 for disabling just fence floor

- added POS dataflash log message

- changed GUIDED behaviour to match copter

- added support for a 4th MAVLink channel

- support setting AHRS_TRIM in preflight calibration

- fixed a PX4 mixer out of range error

Best wishes to all APM:Plane users from the dev team, and happy

flying!

Release 3.2.2, February 10th 2015

---------------------------------

The ardupilot development team has released version 3.2.2 of

APM:Plane. This is a bugfix release for some important bugs found by

users of the 3.2.1 release.

The changes in this release are:

- fixed a bug that could cause short term loss of RC control with

some receiver systems and configurations

- allowed for shorter sync pulse widths for PPM-SUM receivers on

APM1 and APM2

- fixed HIL mode altitude

The most important bug fix is the one for short term loss of RC

control. This is a very long standing bug which didn't have a

noticeable impact for most people, but could cause loss of RC control

for around 1 or 2 seconds for some people in certain circumstances.

The bug was in the the AP_HAL RCInput API. Each HAL backend has a flag

that says whether there is a new RC input frame available. That flag

was cleared by the read() method (typically hal.rcin->read()). Callers

would check for new input by checking the boolean

hal.rcin->new_input() function.