new to FPV, potentially ambitious, point me in the right direction?

[chopperdudes]

Hi all, so i've been reading up a lot about FPVs lately, and am pretty eager to get my hands wet. I've been on and off flying helis and planes for a while now so RC isn't new to me. I'm in university and i decided to take this summer off (instead of working) so i can work on a few projects, including something like this.

I'm thinking of eventually making an autonomous UAV, i.e. waypoints etc (ofc with manual control possible as well), with on board FPV and a long-ish range of say 10km. now i know that this is rather ambitious, so i've somewhat outlined the potential steps i can take.

i'd like to first get the FPV going, then the autopilot can be done with an adrupilot (arduino), and then finally have a wireless system interfaced with a computer (i.e. joystick plug into a laptop so i can get other data/telemetry/up/down link from the model to the laptop), so far i've looked a bit into the xbee system.

anyways to start though I'd like to set up a basic FPV on a foamie flying wing. My futaba 7CHP still works great on 72mhz, call me old school, but looks like that's a good thing since 2.4 isn't really known to be impressive on range. I've been looking at the vid channels, 900 vs 1.2 vs 2.4 vs 5.8. i know ultimately for range the lower the better, and the more power the better. however after doing my research, 5.8 equipments are by far the smallest, and arguably most straightforward to setup. I've been looking at the foxtech 5.8 500mw setup + cp/plane skew antennas. i'll test on a ground vehicle first, but for initial flight testing it'll be mainly park flying in a suburban area limited to i'd imagine 2km. i think that sounds reasonable with the current radio setup i have as well as the FPV setup above as long as i keep it LOS. and i'd reckon it'd get me quite a bit of fun and experience along the way.

couple questions though. firstly how bad of an idea is it to do fpv over a suburban area? (no tall buildings, just houses, and i won't be flying low, but it's not farmland). and how far would 5.8 get me eventually? to get a vid range of 5-10km would i eventually have to go to the lower frequencies? would it be best for me to play around with 5.8 first (easy setup, small) to get more experience before doing anything else? or should i just start with say 900 right away? (probably can't put 900 on a foamie either...) any other pointers would be greatly appreciated!

[TheHeliDude]

Ardupilot has a radio telemetry system that goes with it and just plugs right in. They recommend it over the xbee but I don't know why. It uses 900mhz so that's a reason to consider a different freq for video. I'm using 5.8 with circular polarized (CP) antennas (from immersionRC) with fatshark goggles and I'm getting 2km. I've had it for only a month though, might be able to go farther but that's what I've done so far just in my usual flying spot.

I haven't used the fox tech stuff but I think I read something descent about it somewhere. People seem to like the immersionRC stuff so much they can't keep it in stock so unless foxtech is cheaper my personal opinion would be to go for the immersionRC 600mw video transmitter.

I haven't done long range FPV yet, I just read about it but I think on long range systems people still use CP antennas on the aircraft to avoid "multipath" interference. I experienced that with a cheap hobbyking 900mhz fpv system I tried and I couldn't get any range out of it. For the ground station for long range you'll probably need a patch or helical antenna. The lower the freq the larger a CP antenna needs to be so for 900mhz they are too large. There may be some people using them on 1.3 and 2.4 though, but most commonly 5.8.

There's lots of long range FPV info out there and most of them are using planes so google around a little bit and you might find some info close to your project. I'm just doing it on a quadcopter so my battery limits my range as much as my video signal .

Your 72mhz sounds perfect because lower freq can get you longer range and you want to lose video signal before you lose control of your aircraft, plus you already have it and its working well for you.

I know your in Canada not US, but in the US there's a descent chance right now that they're going to make FPV illegal, and I know our government can be more strict and crazy than yours... But please fly FPV safely because if you hit some old lady or something people will freak out and make laws against it. Our countries are similar enough that people will get ideas from the other on that stuff. I hope I don't sound crazy but I just want to keep flying.

Many FPV fliers would advise against flying over people but if you do, don't do it on your test flights. I am lucky to have a place near me without people but at least do a few flights without being over houses, until you get to know your equipment. There must be an unpopulated area somewhere near you.

Sorry for the long post, but there were lots of questions

[chopperdudes]

thank you, i know i asked a lot of questions hehh, better do more research than needlessly spending more cash.

I have heard about immersionRC stuff and it's mainly about the same as foxtech, except immersionRC is SMP instead of RP-SMP heads (and possibly other differences) which makes it compatible with fatshark but not with foxtech. i've heard good reviews on at least the ease of setup of the foxtech 200mw system and even a video on how to get it working with a gopro. i can find the setup in stock on foxtech's site:

500mw vtx/vrx combo: http://www.foxtechfpv.com/58g-500mw-...xrx-p-246.html
cloverleaf antenna: http://www.foxtechfpv.com/foxtech-58...pin-p-891.html
(and RPSMP to SMP adapter since the cloverleaf antenna combo for RPSMP is sold out)

if you can point to me to a site with the ImmersionRC stuff in stock that'd be great!

yes now thinking about it it'd make more sense to do the test flights out of the urban area, and make sure everything's working fine first. I know what you mean by laws and all, and i'm not out to cause any trouble/will becareful not to cause any, but these things happens with alot of hobbies and even sports (one that comes to mind is mountain biking trails in the urban ravine).

I think i'll do a bit more research on how much range that system can get me, i mean it should be fine to get me started and possible get me thru everything else/have everything else set up on it with the last limiting factor being vid range. i'll keep an eye on the stock, but most likely i'll pull the trigger soon. and if i do i'll report back once i get things set up!

cheers!

EDIT: btw under what environment is it most likely to cause mutlipath interference? a lot of obstacles around for your signal to bounce off of? what other interferences can i get? i've heard that wifi is bad

[aaronredbaron]

just for clarity... they are SMA connectors, not SMP....

take a look at http://www.readymaderc.com/store/ind...cPath=11_30_33

I've been successful with buying from foxtech as well, but I would steer clear of the 500mw... they basically just pumped up the 200mw version and added a cooling fan. The 400mw version is newer and much better... for that matter the 200mw module would give you all the range you need to get started, and lower ouput power always plays better with other components. It is easy to hook up any vtx to a GoPro, but you may not want to. The GoPro 3 is having issues being reliable on the video out (crashing, shuts down when card is full, etc), and even if it works perfectly you have to deal with about 67ms of latency (if my memory serves me) and poor light transitions etc. I've flown with the GoPro, and I'll take a decent CCD board cam over one to fly from any day!

[TheHeliDude]

I don't know anywhere the immersion stuff isn't back ordered. It seems the trick for long range is a directional antenna on the receiver. Many people use patch or helical antennas and get crazy range.

Interference can be caused by like buildings and large surfaces but CP antennas prevent it. I was about to say wifi isn't a problem cuz it's 2.4 but then I remembered newer routers (wireless N) use 5.8. In the US the highest power you can use without a HAM radio license is 25mw though so I'm assuming routers are under that power so you should be ok. I fly in a canyon with neighborhoods on the sides of it and I don't think I'm getting any interference from wifi.

[chopperdudes]

So i pulled the trigger but got the 400mw system instead. heard good things about it and it's newer too. however the 500mw one ISN'T just a pumped up 200 with a fan, it actually has a different chipset, at least according to this:

5.8GHz for FPV RC planes (24 min 32 sec)

there's also threads on RCG and all their systems (200, 500, and the newer 400mw) got great reviews, and ppl getting 5+km on even the 200mw one, and with custom mad antenna and the record for 200mw one is i believe 18km. now 5+km is plenty for me to play with but i'd prefer the higher quality picture of the 400mw over the 200. that's just from what i read, i wouldn't know what results i will get until i actually get mine.

i'd like to at least try using a gorpo because my friend has a hero1 lying around after he got his hero2, as well it can be used for both FPV and recording. i might get a hero3 for my own use (sports mainly, biking/skiing) but would hesistate to put it on my plane...

now until i get my gear (once i do i'll report back), i'll need some extra equipments... need a 72mhz pcm (or i guess ppm would be fine) rx and matching xtals. seems like hobbyking doesn't sell xtals, and they are rather expensive from lhs ($30 for a matching pair), know where to get some? as well perhaps another plane. but fpv gears i can test on one of my on-road cars, i know range will be reduced because i'm near the ground, but should allow me to get familiar with the setup.

[aaronredbaron]

what type of radio do you fly? I have a few good PCM recievers I need to sell... send me a PM if you are interested

[chopperdudes]

So it's been awhile and i've got my stuffs, so i think it's about time i report back on my progress/help out others who needs the information (also a couple questions ). here's a list of what i'm using:

Axn clouds fly floater jet stock everything
http://hobbyking.com/hobbyking/store...C_EPO_PNF.html

old flightpower 2175(?)mah lipo

Futaba 7CHP with PCM park flyer receiver (in actual desperate need of some more PCM receivers as they don't make them anymore...., and yes i just saw your pm aaron)

foxtech 5.8GHz 400mw vtx/vrx with CP antennas
http://www.foxtechfpv.com/58g-400mw-vtxrx-p-550.html
http://www.foxtechfpv.com/foxtech-58...ole-p-890.html

gopro hero1 with cable from readymadeRC,

and this very informative video on how to set it up

How to Setup FPV w/ GoPro HD, HobbyKing 5.8GHz Transmitter/Receiver for DJI Naza Quadcopter (10 min 56 sec)

and the attached pic on the messed up channel selection for this vtx/vrx.

I've flown it twice, both windy days. the first test was just a weight/CG/gopro test with all the equipments added on:

gopro test (1 min 11 sec)

the second is an fpv test with the vrx plugged into my car's entertainment system's screen:

fpv test 2 (3 min 12 sec)

both flights were line of sight and weren't FPV flights. I'm afraid of losing vid or control link so i have an ardupilot on the way here already so i get at least return to launch function. now by no means are either of the videos entertaining, they're just tests for mostly myself to see the quality of the gopro, the vibrations, as well as the vid link stability.

it can be seen from the first video that the gopro recordings are VERY good (at least i'm impressed, even though it's only the first generation gopro), but then again the lighting conditions were near optimal then, have yet to test it on bad lighting. the vid link however seems to be clear most of the times, but at times static. I'm wondering whether that is due to the placement of my antenna as can be seen in the video, and how the plane temporarily blocks it during some banked terms at the right angle and altitude relative to myself. I would hate to have to stick it up to block the view, or stick it to the back and mess up the CG. the vrx was alsoo just randomly placed on the roof of the car, that might be another factor as i've yet to have a true groundstation. I've yet to do a true range test on either the control or the vid link; i will once i get the ardupilot set up with RTL feature.

maybe it's because i'm used to doing 3D on a 450 heli, thus i'm not used to flying high up... what seems high to me looks relatively low in the video.

any comments/suggestions are greatly appreciated, and i will report back once i set up the ardupilot and do a true FPV flight!