FPV assumption

Hi guys, i'm noob here so please excuse my unnatural behavior. Everything i mention below is abstract idea, so please correct me if my assumption is wrong.

1. I don't have concrete ideas of how FPV works (i don't have experience). So my first assumption is "i can do FPV from a laptop." (please do correct me if this is wrong).

2. I'm planning to put Mobius ActionCamera on my quadcopter. Next thing to do is, connecting the camera to AV transmitter (2.4GHz/5.8GHz). I'm planning to use boscam/immersion AV transmitter.

3. I'm not sure about this one. I'm going to connect AV receiver to my laptop (is it even possible?) and after that, i can see FPV through my laptop.

The above steps are just my assumptions. I just feel that using laptop rather than carrying small tv is much better for aerial photography.

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  • Hi Suwandy,

    Are you planing to use the FPV for fast racing drones or for slow flying? The lag it's a very decisive factor on choosing the right FPV equipment.

    The camera: using HD cameras like hte gopro or mobius require more time to transmit the signals causing a small delay, the suggested cameras for FPV applications are CCTV mini cameras of around 700 TVL (resolution).

    The radio: On the radios the transmisison power is given by the amount of milliwatts. You can find radios from 25mW up to 1000mW, the higher the power the longer the transmission distance. But there are two conditions:

    1. Legal issues: You must research about local laws and rules to ensure that is not illegal to use certain frequency at the given power.

    2. Poor power/distance increase ratio: The increase of range is very ineffective with increase in transmitter power. To double your range, the power has to increase 4 times in theory. Let’s say if a 200mW VTX gives you 1Km range, to get 2Km, your transmitter power has to be 800mW at least.

    Once sorted these two conditions is up to you to select your transmitter power.

    Then we come to the frequency. The lower the frequency better penetration to objects will have. So if you are planning to fly in an area where you don't have many obstacles and is mostly open, then the popular 5.8 Ghz frequency will be more than enough, but if you are planning to fly FPV racing through an abandoned building or warehouse and you will go through rooms and walls, the 1.2 Ghz radio would be more suitable.

    Check out this blog from a Canadian company that's specialized on FPV racing drones:

    http://tinyurl.com/ogflboq

    cheers!

  • Moderator

    Just my 2¢ here.....

    I have both a set of FatShark Dominator goggles w/diopter adjustments and a laptop connected via an A/D RCA-USB converter/capture device. I have used both but find that I like flying from the laptop better for one simple reason, I can take my eyes off the laptop in an instant and find my plane in the sky. Wearing corrective lenses for distance I can't see the plane in the sky without my glasses on and I can't wear them with the goggle on, so there is a delay if I need to take the goggles off and put my glasses on if I need to.

    My aircraft is a very slow platform that cruises at around 25-30 mph and at that speed I haven't noticed a delay. That said I'm sure there is some delay however unless I were flying close to the ground or flying faster I find it to be quite satisfactory. The nice thing about the goggles is the immersive experience you get, shutting out the rest of the world. As someone already said that can also be it's downfall.

    Regards,

    Nathaniel

  • I have this setup

    • An Iris
    • Boscam 600Mh Tx/Rx they about $99 to buy as set.
    • Both Mobius and GoPro, so whichever is more efficicient for particualt use. Both fine for FPV.
    • SkyZone goggles. These have 2 antenna and connect nicely natively to the boscam tx.
    • The Boscam rx I have put into a case (similar to pelicans) with a montior..so now I effectively have 2 video receiving points.
    • The monitor is just from a philips portable DVD player which had a 2nd screen (once used for keeping kids quiet in car on road trips) Works great.
    • They all have 9-12v input so a I can power my station from a portable car battery jumper pack, or a spare 3S Lipo.

  • If you are planning to actually pilot the aircraft via FPV, I would not suggest doing so through a laptop.  The delay induced by going from video receiver > USB adapter > Processing > Screen is not conducive to FPV piloting.  I would only do this for the purpose of recording and for non-critical live viewing.  Also, the Mobius will have a slight delay of it's own, about 1/2 a second a believe.  And that is actually a very very long time when it comes to safely maneuvering an aircraft.  Some people find it is not a problem, others will not do it.  You would be better off with a more conventional FPV camera and use the Mobius for recording HD video on it's own.

    For actual piloting of the aircraft via FPV, you would want either goggles or an LCD screen attached to your controller.  That way it is just going Video Receiver > Screen with no delay.

    • Ah, i forgot to mention that i used quadcopter with missions:

      1. To do up-close visual check (which i assume FPV will do the job)

      2. To take picture if necessary

      So no recording or big-explosive motion in this activity (let's hope the pilot do well). But still, thanks for informing me about the delay + mobius' innate delay too (i can already imagined the lag). Based form your flow process:

      video receiver > USB adapter > Processing > Screen

      If i still insist on using laptop, then all i need to add is AV to USB (USB adapter) isn't it? then plug the USB to laptop. But wait, how can my laptop detect such device?

      a more conventional FPV camera

      May i know the example of conventional FPV camera? i would like to know my possibilities.

    • On the goggles vs screen thing, keep in mind where you will be flying.  At a flying field, it is no big deal.  But if you're at some other location open the public, you will have no idea what is going on around you once you put goggles on.  What makes goggles so great is also their downfall depending on your location.

      With 1.2Ghz, you run the chance of a harmonic on 2.4Ghz interfering with 2.4ghz control. It doesn't effect everyone, but it happens.

      • WELL!! 1.2 GHZ DOES NOT GIVE YOU MORE RANGE!! 1.2 Ghz penetrates building's and trees unlike 5.8ghz.

        wifi FPV is new you will see meany flying web cams before the summer is over! but wifi adapter attaches to traditional FPV Rx . I agree a laptop is no good better on a phone or tablet or both better in bright sun light delay issue will soon be gone as well .

        • Absolute wrong. Lower frequencies give more range and better penetration thru solid objects. Its part of the reason why wifi is higher than mobiles and thats even higher than other long range stuff. None of the space probs use 5.8g because its horrible, they all use much lower frequence. 

          Im not quite sure if this is accurate but just look at water, longer waves travel further than tiny lots of wave patterns. The more the wave goes up and down the more chance for something "cutting" or slowing it down. Im guessing thats why lower frequences get more range than higher. They vibrate less over time so they lose their power less over time.

        • The point you emphasised with caps and exclamation marks above is incorrect.
          If all else is equal, a lower frequency will travel further. This is why you can hear 130db of bass coming from a car 2 blocks away, but can't hear the accompanying treble until it drives by. It is why whales can communicate over hundreds of kilometres under water using ultra low frequencies. It is why Long Range Systems operate on the 433Mhz band rather than 5.8Ghz.
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