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Litchi FPV boost + ITELITE

Discussion in 'Phantom 2 Vision + Mods' started by Dmitriy S, Aug 24, 2015.

  1. Dmitriy S

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    I installed an ITELITE antenna and the FPVLR dipoles bird side, and I'm using a Nexus 7 running Litchi. In the Litchi app there is an option to boost FPV... does that actually work? Should I turn that on for even more distance with the antenna setup?
     
  2. bbfpv

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    yes, it works. increases output power. I dunno know about the FPVLR kit, but it works well w/ my Itelite DBS Tx mod on my V+.
     
  3. robert stephens

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  4. DOUGLAS FERREIRA

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    what should I set the dbi setting to in the Litchi app ??? what is everyone setting it to, and does it actually work ????
     
  5. cubandrone

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    Hey man, can we have pics, thx
     
  6. bernek

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    I left it first at +13dB that was default but then the camera froze during flight a few times and once I couldn't even reconnect back to it (black screen with telemetry). After this incident I've tried 9dB that worked perfectly and I'm still using it.

    I think you should calculate your final dB rating using this table:

    dBm to Watt Conversion Table

    The problem is we don't know what is the default dB setting for the camera ... as you can see the raise in dB is logarithmic so for example the power doubles from 17dB to 20dB and that also almost doubles the heat produced.

    A Litchi dev could help us and give us the starting dB value (for non boosted FPV) so we know how much to add and we can check in this table to see the power output in mili watts so we can better tweak it.

    They said the +13dB value is a good balance between heat and performance ... well depends on where you start from :) I would say lower values between +3dB towards +11dB are more "safe" and not prone to overheating.
     
  7. Mark The Droner

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    I would be careful with the boost on the P2V+. First you must take into account that the transmitter is going to heat up and it's going to be operating at a hotter temp than the DJI engineers intended. Secondly, there is a known issue with the transmitters over heating on the P2V+. So put those two facts together and measure the risks.

    I'd also consider air temperature during the flight. Obviously, the hotter the day, the more apt your transmitter will overheat.

    How much to boost? Again, I'd consider air temp. If it's a hot day, I wouldn't boost much if at all. On a cold day, if I was going to boost, I'd be inclined to boost towards the high side.
     
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  8. bernek

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    Mark I'm on the P2V (non plus) and the antenna and wifi (transmiter) is inside the egg camera. I believe it has a fan but it overheats easily. I think the base dB for the egg camera should be around 17dB so I will only add 3dB for 20dB would be more than enough :) either way I can't beat the wifi range with my RC now so not quite going to boost fpv (camera module).

    The 9dB settings worked nicely so I would try lower it even more to get a setting good to last no matter the temperature that I'm flying in. The shutdown temp for egg camera is 75-80 degrees Celsius or something similar (90 would be max) - I've read this in the DJI manual can look for exact numbers if you are interested. The outside temperature is 25-30 degress Celsius during hot summers so its not that hot outside.

    Bottom line I still need to further experiment with higher outside temperatures (now its only around 20-22 degress Celsius) to get the all around value to fly with safely.
     
  9. Mark The Droner

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    Okay - re P2Vs, yeah it does have a fan, Dirk proved that when he dissected his egg with photos a while back. And you can hear it too.

    You said "I believe it has a fan but it overheats easily." What overheats easily? The transmitter causing burnout, or the camera causing shut down? Because I haven't really seen or heard much about this.

    I haven't had any overheating problems with my P2V egg transmitter and I haven't really read about them either. Yes - the P2V+ is known to have problems, but I haven't really seen or heard problems with our egg. So I kinda assumed that was because it's already operating at a lower dB to start with, which means lower heat, and therefore, it's safer to boost. We wonder why the range is poor on the stock P2V - that's one of the reasons.

    When you say " I think the base dB for the egg camera should be around 17dB", are you guessing that's what it is, or are you saying that's what you think it should be?

    I've never had my FC200 shut down due to heat, but then again, I try not to fly if it's really hot - because I'm worried about the battery!
     
  10. bernek

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    If I set 20 dB in Litchi I can only fly for 10-15 minutes then I get a black screen (only happened twice in different flights). I think the camera overheats from the heat generated by the transmitter inside. Maybe I'm wrong or my problem came from elsewhere. With DJI Vision app never had any issues and with Litchi if I push the dB too high I get these black screens (no videostream from camera) but the telemetry is working. I assumed what the problem was after reading about the automatic shutting down of the camera to prevent damage due to high temperatures (in DJI manual).

    If the RE500 (original extender) is <=17 dB from DJI specifications I would say the camera should match that power since it has the exact same directional antennas inside and the video stream is coming from the camera to the RE500 so it needs some transmitting power to work at 300 meters LOS. Most of the routers and access points work around 14-17 dB and their range is similar. Again maybe I'm wrong but I would expect those values from the camera transmitter. Also the power from the camera transmitter can be controlled electronically so it varies with range hence the posibility to be altered but some simple commands that Litchi is sending to it.

    I guess it sends something like this:

    ifconfig wlan0 down
    iw reg set BO
    ifconfig wlan0 up
    iwconfig wlan0 txpower 20

    I can try test it if I find the open port for communication. I've seen that on some website including the default password set by DJI. Those guys were installing OpenWRT as a web interface on the range extender but it should be similar for the camera wifi board itself.

    The range extender transmit power can also be modified and that's the reason those guys were installing OpenWRT on the range extender to be able to "save" the settings and easily modify them.

    Here's a quick 'HowTo' I put together for installing a WebUI onto a DJI Phantom…

    Install OpenWRT WebUI on Repeater/P2V+

    Bernek.
     
  11. Mark The Droner

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    Cool! Very interesting and great info. Thanks!

    I've never had my camera go black but then again I haven't used it at the max setting - 20 dbi, very often. And if it was going to be a warm today, say above 80F, I would not run it that high. I think you're right, I think it overheats from the transmitter. So the camera shuts down but apparently the transmitter stays on since you're still getting telemetry.

    In addition to the Litchi power boost, there is another app - an Android app, that does it too, called Vision+ Utility. But I have never used it. And I'm not sure if it works for the P2V. I need to check it out but I always forget :p
     
  12. bernek

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    I installed OpenWRT on my RE500 (that is parked now since I have the RE700) here are my findings accordingly:

    [​IMG]

    [​IMG]

    The RE500 is working for both interfaces at max 27 dB ! that is 501 mW also is the maximum power settings that is allowed. I also took another look and seen 20 dB on that config webpage. I think its changing the power like I said maybe between 20 dB and 27 dB.

    20 dBm is rougly 100 mW and 27 dBm is 500 mW !

    At least this is what I get from Luci :) There is no need for any app since you can install OpenWRT and use Luci as your web interface.

    I will install it to RE700 and post my findings.
     
    #12 bernek, Jun 3, 2016
    Last edited: Jun 3, 2016
  13. bernek

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    A better idea that went trough my mind is using the RE500 on the P2V itself and RE700 on the ground with ITELITE ! :D this can be wicked FPV range !

    I just need to find a way to mount the RE500 on the P2V :p and measure the weight of it first ... but its doable since you can change all the settings for their virtual interfaces in Luci.
     
  14. bernek

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    I think the RE500 is more powerfull than the egg camera transmitter itself and I would connect them like this egg -> re500 -> re700(itelite) I still have to think about the SSID/AP/WDS modes for each for this to work but I really think its doable.
     
  15. Mark The Droner

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    I think I lost you somewhere.

    If we know the 500 is greatly inferior to the 700, then the power output as stated in this thread makes perfect sense.

    I think the egg transmitter is lower than any other.

    Why not just put an amp on the bird between the egg and the modded antenna?
     
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  16. bernek

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    How is the power reported to FCC measured ? I'm not sure :)

    Take a look at this article: dB vs. dBm - ISA

    I'm talking dBm (absolute value of power) but you made me have my doubts about what I've found in the RE500 settings presented in Luci interface ...

    I don't have a modded antenna on the bird yet and my fpv range with ITELITE + RE700 is more than I can cover with my 5.8GHz RC :S

    Will have to double check my affirmations still :)
     
  17. Mark The Droner

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    So you have no mods at all on your bird? What is your max range so far?
     
  18. bernek

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    No mods on the bird at all. Only RC and RE700 in FCC mode and ITELITE DBS-01.

    with RE500 without ITELITE - 350-400 meters ~ 1300ft

    with RE500 +ITELITE got 1.2km ~ 0.75miles

    with RE700 +ITELITE got 2.5km ~ 1.55miles (I only done 1-2 flight tests with RE700 taking off from a zone with quite a few 2.4 GHz but the RC signal was lost first)

    I have to further test it :) I hope tomorrow will be a sunny day we had lots of rain.

    These are all without any boost from Litchi and some of the tests were done using DJI VISION app.

    I really need to improve the egg camera antennas or to mount the RE500 on the bird and config the both extenders. I also need better 5.8GHz antennas on the bird and I'm quite sceptical when it comes to the black glue of death ...

    What antennas do you recommend for this combination ?
     
    #18 bernek, Jun 3, 2016
    Last edited: Jun 3, 2016
  19. Mark The Droner

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    The dipoles on the FPVLR site are good for both. Try to make sure they are made with the BLUE cable rather than the black cable.

    Here's how to get past the black goo of death: Black Glue of Death removal instructions

    Good luck in your endeavors and keep us posted!
     
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  20. bernek

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    I can't order from FPVLR since I'm in Romania and the postage is expensive and very slow. I need to find a similar product on ebay.co.uk or china.

    Thanks for the link with black glue of death :)