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Losing the Shrike Again - Still Learning!

Posted by Trent at MyGeekShow on July 2, 2012 at 4:40pm

 

Okay, okay. I know what you are thinking... Didn't you learn anything from the last episode? We did, but this one totally surprised us. We were just going up for a few minutes to test the new antennas and a new field when we lost the plane.

So, what happened?

Not totally sure why the APM seemed to struggle to find it's way, and we may never know as we still didn't have the DF card working (it's showing an error, and we've tried removing and reinstalling, and updating the firmware, still no luck) and we don't have telemetry yet (it's in the mail!).

One thing is for sure though, the flight battery was not working correctly. One of the cells wasn't holding a charge very well, but it seemed to perform just fine at first. However, when we finally set it to RTL it just couldn't keep altitude, no doubt caused by a weak & dying battery.

We are learning a lot, and are gathering all your suggestions to make a big improvement episode.

This is so much fun!

Thanks!

-Trent & Nick

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Comments

  • Dusan July 7, 2012 at 6:15am

    I wish there is an easy answer to this question, so many factors are at play when determining this.

    This may be  good place to start http://en.wikipedia.org/wiki/File:Patch_antenna_pattern.gif

    usually more gain means "sharper" beamwidth .

    10dBi patch usually have 45-60 degrees beamwidth

  • Mark Bolton July 6, 2012 at 1:35am

    Thanks Dusan,  Have or on ordered almost most of the kit you suggested. Thanks very much to DIY drones etc.  

    What coverage (degrees?) does a patch generally deliver?

    Cheers

  • Dusan July 5, 2012 at 1:41pm
    Ok here is my 5 cents
    1.Fix FPV clover on the airplane as all this comments say it need to point up in order to have best performance.
    2.Have high gain patch or Yagi on the ground (you will need to track the model with it but it should give you nice range and you can do it by hand. Yagi is more "sharp" and need better aim, patch is more "wider" and more tolerant on aim)
    3.On RC TX side get Frysky http://www.alofthobbies.com/diy-telemetry-module.html (us based company with fair price policy) or RX side get http://www.alofthobbies.com/frsky-6-channel-receiver-w-telemetry.html or you might want to go with 8 channel one. also get http://www.alofthobbies.com/lcd-display.html it can show you signal strength,buzz on signal loss, low battery, all sort of options for alarms
    4. get patch antenna for your TX it will significantly increase your range
    5. get telemetry module from 3D robotics ( if you allready don't have it )
    6. AND THIS IS MOST IMPORTANT ONE Check range for all of your equipment on the ground first,than confirm it in the air. Its nice to know your equipment limitations
    7. Get that data logger on APM2 to work ( its black box that you can use for lather analysis )
  • Bot Thoughts July 3, 2012 at 1:23pm
    Um do you want one of my custom lost model alarms free gratis? :)
  • Mark Bolton July 2, 2012 at 10:10pm

    Tridge,  would any of these aerials make an easy and useful upgrade to the stock units?  I need to ship the filter to Aus anyway, might as well stock up the parcel!

    http://hobbywireless.com/index.php?main_page=product_info&cPath...

    Thanks

  • Mark Bolton July 2, 2012 at 6:43pm

    Thank you

  • Developer
    Andrew Tridgell July 2, 2012 at 6:39pm

    Hi Mark,
    I think its worthwhile adding the filter on the plane, particularly if the radio is close to the GPS in the airframe. You don't need to use a filter on the ground radio
    as that is a long way from your radio.
    I found the filter helped a lot with good GPS lock on my SkyFun, where the GPS is
    less than 30cm from the radio antenna.
    I've also asked Craig at 3Drobotics to look into the possibility of building these sorts of filters directly into the radios for a future revision.
    Cheers, Tridge

  • Mark Bolton July 2, 2012 at 6:22pm

    Hi Tridge.

    I have purchased the 900mhz 3DR telemetry kit.  Are you recommending that you add the filter to the telemetry aerial set up on the plane? (ground side as well?) or to the FPV kit?

    Thanks

  • Alex July 2, 2012 at 6:20pm

    "still didn't have the DF card working"

    Mine was intermittently (mostly not!) working until I stuck a bit of tape on the back of the card and put it in to make it fit more snugly. Seems to be that some of the cards aren't making good contact... I'd suggest trying this!

  • Developer
    Andrew Tridgell July 2, 2012 at 6:11pm

    Hi Trent and Nick,

    I think that doing non line of sight flights without telemetry is not a good idea. I suggest you wait until your telemetry radio arrives and is working well.

    When you do get your telemetry radio you should also look at getting a filter for it to prevent GPS interference. For example:

      http://hobbywireless.com/index.php?main_page=product_info&produ...

    you may also need some SMA to RP-SMA adapters, see http://www.ebay.com/sch/Coax-Cables-Connectors-/48704/i.html

    Right now ArduPlane has no dead reckoning support, so if it loses GPS lock then it won't be able to navigate at all. I'm looking at adding dead reckoning for a future release, but for now you need to be careful to minimise any GPS interference sources for non-LOS flights.

    Cheers, Tridge

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