ArduPlane 2.73 released

I've just released ArduPlane 2.73 as a bug fix release for several important bugs in 2.72

The main reasons for this release are:

  • fixed a noise and scaling problem with airspeed sensors
  • fixed a potential flyaway problem with the L1 navigation controller
  • improved handling of poor GPS velocity for attitude correction

This release does not contain the new attitude controllers that I previously said would be in 2.73. Paul and I decided that it would be better to hold those over to the next release, and get this release out with just the above critical bug fixes.

The airspeed problem stemmed from a changed introduced in 2.72 to make ArduPlane automatically scale analog inputs with board voltage. That change was good for voltage and current sensing, but it added a lot of noise to airspeed sensing as the 3DR airspeed sensor is ratiometric (the sensor output scales with the supply voltage). The fix was to add support for ratiometric analog inputs. This release also fixes a bug in the airspeed ratio handling. To confirm the fix I have been driving around in my car with an APM2 and PX4 logging airspeed and GPS speed - that test confirmed the airspeed sensing is now accurate.

The flyaway bug in L1 was caused by an unusual situation where the previous waypoint was equal to the next waypoint, which can happen when a mission is interrupted and restarted. The L1 controller would then level the wings and fly straight ahead until the operator intervened. The bug fix was to make the L1 controller detect this situation and track directly to the next waypoint. I don't think many users would have seen this bug, but it definitely could happen and warranted a bug fix release.

The GPS handling bug was related to the MTK GPS, which can be very slow to report loss of GPS lock, which could lead to very poor attitude from DCM and even a crash if the plane tries to turn while the GPS is reporting incorrect velocity information. The fix was to watch the satellite count, and stop using the GPS velocity for accelerometer correction when it had less than 6 satellites. This is selectable with the new AHRS_GPS_MINSATS option.

Other changes

While this release doesn't have the new attitude controllers I decided to leave in some other smaller changes that have been made since the 2.72 release that I consider to be low risk, including:

  • fix the PX4 barometer driver to run at full rate
  • fixed handling of a saturated compass on PX4
  • added COMPASS_ORIENT option to support external compasses
  • fixed the compass in HIL simulation
  • added GCS messages to flash logs
  • allow 3D accel calibration over MAVLink
  • Added new ELEVON_OUTPUT option
  • removed MANUAL_LEVEL option (manual level is now always on)
  • improved pitch handling when inverted

Of these, perhaps the most useful is the ELEVON_OUTPUT option. That makes it possible to setup your transmitter with normal aileron/elevator and get the APM to do a software elevon mixer on output. That gives better control in FBWA mode than the previous elevon options.

I recommend that all users of 2.72 upgrade to 2.73. Happy flying!

Cheers, Tridge




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  • Dear folks,

    Where can I find The NAVL1_PERIOD & NAVL1_DAMPING parameters in the Arduplane code?

    Which tab?


  • Folks I have a doubt about a problem during a flew test yesterday.


    If you see the data I switched the fly mode from auto to RTL ( lime 16222 of txt document). The plane ( HK 1.8 mts) did not came back to the home, it start to do something like a circle losing altitude and later it did something like a flyaway.


    I switched to auto ( line 16674) and them to manual in order to see what the plane did and return it back to me manually.


    There were some messages in those lines that I did not understand very well.


    I am not sure if the problem is with my current parameter set up because in the graph you could see that the Nav_pitch and Pitch did not work as it have done. I will probably have to much I value in the PTCH2SRV_I.


    I have attached the graft with Nav Pitch and Pitch values during the event.


    Thank a lot for any feedback.




    2013-06-05 18-25 1.log

    2013-06-05 18-25 1.kmz

  • Problem I get during compiling Arduplane 2.73 using Arduino IDE

    ArduPlane:230: error: new declaration 'uint8_t digitalRead(uint8_t)'
    C:\Users\abdkadma\Desktop\PhD Work\ArduPilot-Arduino-1.0.3-windows\hardware\arduino\cores\arduino/Arduino.h:100: error: ambiguates old declaration 'int digitalRead(uint8_t)'
    ArduPlane:1287: error: expected constructor, destructor, or type conversion before 'int'
    ArduPlane.pde: In function 'int SKETCH_MAIN(int, char* const*)':
    ArduPlane:1287: error: 'OK' was not declared in this scope
    compat.pde: In function 'uint8_t digitalRead(uint8_t)':
    compat:33: error: new declaration 'uint8_t digitalRead(uint8_t)'
    C:\Users\abdkadma\Desktop\PhD Work\ArduPilot-Arduino-1.0.3-windows\hardware\arduino\cores\arduino/Arduino.h:100: error: ambiguates old declaration 'int digitalRead(uint8_t)'

    Any suggestions?

  • Hi i have ardupilot 2.73 and i will reproduce the log file load on board because i have many loss packages of fligth wiht the telemetry. I try whit " APM Log visualizer" and with the option " Recreate KML" but  I dont see the misión in Google Earth

    It´s a problema with Arduplane 2.73?

    Can help me?


  • Hi to all...i receive this e-mail from the 3dr team...the airspeed not work and it's erratic the measure????any user  receive similar e-mail??


    best regard...

  • Nice to see the new version.

    Although I got problems with the 3DR Power Modul. The battery voltage is completely wrong.

    And since the new Mission Planer does't allow to change the input voltage I can't adjust it...

    Is there a way to get around this problem?


  • Issue loading Arduplane 2.73 HIL FW on APM 2.5:

    I was actually testing the HIL Simulation with my new APM 2.5 board & FlightGear, It seems to be HIL firmware loaded successfully with out any errors and completed with a msg "Done". But as i noticed once i connected back with mission planner it's connected and read all the parameters and after that there is no response from APM2.5, Seems to be stuck and all the three status led's are on..No idea whether it's the problem with HIL FW 2.73 or APM HW. When i reloaded with regular quad fw V2.9.1b everything is working fine and GPS locks and shows the information..Can somebody help me to resolve this???. Thx

  • Using AP 2.73 with the orientation 90 Degrees (Clockwise). I have this set in the Parameters and the HUD responds appropriately.

    On the Flight Planner screen should the plane icon also correct for this and show the plane facing North if it is facing North or will that be 90 out?

    I am sure it corrected this when I setit up but now shows 90 degrees out?

    Thanks guys.

  • Here i have attached the succesful tlog and r log files. I have attached the rlog file of the failed auto take off as the third attachment.



    2013-05-26 16-41-31.rlog

    2013-05-26 16-41-31.tlog

    2013-05-26 18-04-36.rlog

  • Hey Andrew!

    Well I was using Arduplane 2.73

    Here are my parameter file, tlog file and waypoint files.

    I was wondering if the plane was doing the 100 % throttle with slight nose down to pick airspeed.

    Please do have a look and give in your inputs! Thanks

    2013-05-26 18-04-36.tlog

    x8 throttle slew rate 100.param

    Jakkur Auto take off and land.txt

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