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Posts posted by Spitfire76

  1. 10 hours ago, erfan said:


    how can I use the new update (copter 3.6.9 ) for the simulation (sitl) ?
    I am going to download the firmware (3.6.9) for my flight controller (px4v3). How can I upload this firmware for the simulation test ? 


    Although it can be run natively on Windows I prefer to create a virtual machine running linux using Oracle's Virtualbox. 



  2. 1 hour ago, erfan said:

    yes please That would be great.

    Where would you like me to send the file ?. Its 856Kb in size ?. You can send me a direct message if you like with the details. Once you have the file you should be able to use Mission Planner and install it as custom firmware.

    1 hour ago, erfan said:

    Can I also ask how do you test it in the simulator? what kind of simulator is it? 

    As you can see from the Ardupilot documentation there are several software simulators


    but the simplest is to use Software In The Loop (SITL)


    1 hour ago, erfan said:

    could you please explain how to use the simulator  ?

    Without going into details at the moment I have it running on linux (Ubuntu 16.04) desktop and use another laptop running Mission Planner to connect to it. 

    1 hour ago, erfan said:

    what things can you simulate in that

    Most of the same things as using the hardware flight controller. For example you can arm, take off, change mode, execute missions etc.


    1 hour ago, erfan said:

    it does not bop up or down I would say. 

    In that case it sounds like the MS5611 is more of an accurate barometer than was used in some of the earlier versions of the Pixhawk. 

    • Like 1

  3. @erfan - I've made a change to the config.h file so now the RTL_ALT_MIN is set to 100 cm instead of 200cm. I've tested in in the simulator and it seems to work. So if you are at 50cm when you trigger RLT it will climb to 100cm instead of 200cm. If you want to try it at your own risk I can upload the firmware (apj file) to your dropbox or similar service. Again though you fly it at your own risk.

  4. 5 hours ago, Ixaon said:

    The Hobbyist Registration is just the $5 Registration you pay the FAA to Register your drone. That’s it. There is no hobbyist test at the moment that I know of. I just researched this for myself. Working on my Part 107 now too. 

    We’ll see what they do for Hobbyists over the next several months with the recent changes.

    One big recent change for hobbyists is this


  5. 7 hours ago, erfan said:

    where can I FIND THE CONFIG:h file for version 3.6.8 ?

    The file is part of the source code which is available on GitHub.

    7 hours ago, erfan said:

    then I  should change the code and recompile the software?

    You will need to setup a development environment


    Its a bit involved if you are not familiar with compiling software.

    7 hours ago, erfan said:

    so would you think if I get Teraranger I can control RTL as well ?could you explain that ?

    This does not avoid changing and compiling the code for the RTL return altitude to be below 2m. What it typically provides is a more accurate way for the flight controller to measure its altitude which is of course more important when the UAV is close to the ground. However it looks like the Pixhawk4 is equipped with a MS5611 barometer that's reported to have a resolution of 10cm. I am not sure though if that means if the UAV is at 50cm it could actually be between 45-55 cm or 40-50 cm. The Terrabee Eco 60M has a reported accuracy of +-4cm at 14m and below so not much more. When you fly the UAV at 50cm is it stable or does it bop up and down ?.

  6. 1 hour ago, erfan said:

    Thanks for checking, 

    so it is the problem of mission planer which its param is from 0-8000 cm while it should be 200-8000cm as ardupilot stated.

    Please ket me know if you have found sth new,


    Here is what I found. The behavior is not caused by mission planner but its hardcoded in the ArduCopter firmware's config.h file.

    # define RTL_ALT_MIN 200 // min height above ground for RTL (i.e 2m)

    It looks like to change it you would need to recompile the software.

    2m is quite low for outside, especially considering the accuracy of the barometer. Why do you need to fly so low ?. 

  7. 2 hours ago, erfan said:

    My problem is when I am flying 50cm above the ground and when RTL triggers the copter goes higher although I have set RTL_alt to 50cm ?
    it was going more than 2 meters...

    I just checked this by testing with SITL (Software in the Loop) and even though I set the RTL_ATL to 0 when RTL is triggered it does climb to 2m instead of maintaining its current altitude of 0.5m. 2m is of course 200cm which is what the documentation is stating as the lowest value that RTL_ATL can be set to although in mission planner it does allow you to set it to 0 and states that with 0 it should maintain its current altitude which is not the case when the current altitude is below 200cm. I'll check into it a bit further as maybe there is a good reason for the minimum 200cm altitude.

  8. 19 hours ago, erfan said:

    today when I flow the first option happned : so in the monitor showed battery fail safe mode and suddenly the copter went higher and I had to switch to stabilize to get the control , what I expected was to land because the Parameter RTL_ALT_final is set to zero which is landing,

    does any one know what is the problem that it went higher and didn’t land?!

    The way that RTL works is that once triggered the craft will climb to RTL_ALT (or maintain its current altitude if RTL_ALT is lower). The idea here is to avoid any obstacles like trees or buildings as the return path is a direct flight path to the launch location which could be difference from the outbound flight path. My understanding of RTL_ATL_FINAL is to tell it what altitude you want it to be once its reached the home location and setting it to 0 will cause it to land but maybe you don't want it to land but hover at a certain height.

    If you simply wanted the craft to automatically land once the failsafe was triggered just configure LAND mode instead of RTL in the failsafe screen. 


  9. 3 hours ago, Chase Flynn | UAV Coach said:

    Hi @Spitfire76

    Thanks for sharing this, it is a very interesting UAV challenge. I am a senior at Embry-Riddle Aeronautical University and we had an assignment that was based off the Outback Joe Challenge. We had to choose a platform that we could customize. However, if I remember right our drone had to deliver a bottle of water and medical supplies instead of visual confirmation that Outback Joe was alive. It is cool to see this application outside of my school application. Thanks again for sharing this! 


    - Chase 

    Hi @Chase Flynn | UAV Coach 

    This is the first time that I've studied the rules this early on in the competition and now I am tempted to come up with a design to meet the 2020 challenge. It looks like its going to require 2 aircraft, potentially a fixed wing as the transient craft between the base and the remote accident site that carries a multi-rotor type craft that is deployed to enter the shed to provide the communication between Joe and the medical rescue team that's on route,

  10. 12 hours ago, erfan said:

    Does anyone know what is the reason why my copter when I throttle a bit down descends too fast? I am in stabilize mode 

    You maybe aware of this but in stabilize mode the throttle simply determines the speed and therefore thrust of the motors. Were you expecting a more controlled decent ?. If so you might want to try descending in Alt hold or one of the other modes that uses Alt Hold to control altitude. 


    As you will see in the above in Alt Hold mode the throttle stick is now controlling the rate of climb or decent rather than simply the thrust of the motors. Also note that a range finder like we have discussed in another thread is good to have if you are using this mode as its more accurate than the built in barometer of the flight controller that uses air pressure to sense altitude. 

    • Like 1

  11. 6 hours ago, erfan said:

    1)you mean using a power module ?! 

    It looks like if you use one of their Evo series sensors then power is obtained from the Pixhawk.


    What you may need though is an I2C hub as your compass maybe already be using the I2C port but I would need to check into that further.




    10 hours ago, erfan said:

    1) is this for controling the height?! 

    If the sensor is pointing down it can be used as an accurate way of measuring the distance the aircraft is off the ground.


    10 hours ago, erfan said:

    Or is it like collision avoidance sensors?

    Yes, if mounted horizontally and configured appropriately although several sensors would be need for all round collision detection.


    10 hours ago, erfan said:

    2) the Adapter Tera one I2C supports 3-4s battery.

    No a big deal, in that case you just add a BEC that supports a 6S input voltage and provides a 3s output. 

    Again, I have not used any of their products so I can't say if they work well or not although as I mentioned before I am considering using one of their products for use in a fixed wing UAV. Also I may look into their EVO sensors rather than their first generation Terra Ranger One.


    • Like 1

  13. 7 hours ago, erfan said:


    I have two questions:

    1) I wanted to know why some people when tuning change PID values of throttle accel but some change the throttle rate,

    what are their effect on the copter?!

    What is the difference on the copter?!

    can anyone explain that?

    2) why I can not increase my throttle accel P and I value?!

    the max p is 0,5 and the max I valie is 1 


    I've never had to mess the those values so I can't say why its not working. In my experience of building several drones using ArduCopter the default values have worked fine although I do plan on using the "Autotune" flight mode one of these days. I believe that it just changes the PIDs though for roll, pitch and yaw and not throttle. Have you had experience with other drones ?. I ask because when I first started flying my landings were not exactly soft and it took some practice to land well. 

  14. 5 hours ago, erfan said:

    I need to fly at lower as possible ...?

    It is but I would not rely on the barometer that's in the flight controller. You need a more accurate range finder at low altitudes.


    I've used an ultrasonic one as it was the most economical 


    but if I were to add one these days I would try out one of these


    I'm currently building a fixed wing drone and a rangefinder is essential for antonymous landing so will likely use one of those although they are that cheap.

    • Like 1

  15. On 5/12/2019 at 12:37 PM, Spitfire76 said:

    It looks like the FENCE_RADIUS parameter range is 30 to 10000m so I suspect you will get an error if you try to set it lower

    I tried this on the ArduCopter SITL and although it does warn you that the value is out of range it does give you the option to continue and change it. So yes you can set it to 2 m but again the GPS is not so accurate so having such a low radius may cause problems.

  16. 25 minutes ago, erfan said:

    do you know what happns if I set the fence_Radius to 2 meters althought the min is 30 meters?

    It looks like the FENCE_RADIUS parameter range is 30 to 10000m so I suspect you will get an error if you try to set it lower. Typically the GPS is only accurate within a few meters, same with the altitude unless you are using a lidar range finder instead of the onboard barometer. I believe that GPS RTK is more accurate (down to a few cm) but I have no experience with its as it out of my budget.

  17. 42 minutes ago, erfan said:

    how to check at how much percentage is my throttle exactly?!

    50% throttle is roughly when the throttle is in the center. More information here


    You can select which compass to use on the compass calibration screen in MP.