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Oct 14, 2020, 03:21 AM
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Quote:
Originally Posted by PetruSoroaga
Is ALFA AWUS036NHA still supported in Open HD 2.0.1?
I tried to use one, and on boot, it tells me all the network cards are successfully setup (monitor and frequency), but on the OSD I see only the other cards, and they show as -128dbm (I have video image though).
If I remove the card and reboot (using only the other network cards that are attached), all works fine as expected.
I tried with an Open HD 1.x and EzWifi (on the same hardware) and it works fine (ALFA AWUS036NHA). So, looks like something is broken on 2.0.1.

By the way, you have a bug in your video bps computation on the RX side: you compute video bps every 500 ms, but you forgot to multiply the final result (bps) by 2.

Petru
ALFA AWUS036NHA works here on 2.0.1 stable- only tried as a single card on ground and using the new osd (app)...


Stephen will be releasing 2.0.2 stable in the near future(testing now), which has bug fixes

He will also be releasing 2.1 soon (weeks to months) which supports sbc other than the pi.. and too much other stuff to mention


For the app I will have adsb (real aircraft traffic) support via network api (thru opensky) or adsb messages recieved via an sdr. For the sdr adsb it parses messages thru dump1090 program which is packaged now for us thanks to Stephen! I tried to upload a video but rcgroups errored out AFTER i waited for the video to upload. That was the last straw with rcgroups for me... Unsubscribing.. buh bye

I'll reitterate... OpenHD forum https://discuss.openhdfpv.com/ or telegram or github or youtube random videos
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Oct 14, 2020, 04:38 AM
www.petrusoroaga.com
PetruSoroaga's Avatar
What's the telegram link again?
Thanks!

Tried to go to https://t.me/OpenHD_HDFPV (from a regular computer)
but it tells me I can view it only on a mobile app?!
Oct 14, 2020, 05:01 AM
Registered User
You could try this if you don't like to install the mobile or desktop app:
https://web.telegram.org/#/[email protected]_HDFPV
Last edited by socke; Oct 14, 2020 at 05:13 AM.
Oct 14, 2020, 09:39 AM
Registered User

Ordering a Pi 4B for GroundPi


Hey,

I just wanted to verify, does it make any logical sense to spend an additional 15 euro's or so to order a rasberry pi 4B with additional RAM, such as 4GB or maybe even 8GB over the 1 or 2 models?

Cheers,

Herre
Oct 14, 2020, 10:54 AM
UAV Flight Operations Manager
Yes the Pi 4 has a real USB controller, so itís much more stable and capable of dealing with the stuff we connect (such as our WiFi adapters and USB cameras and so on).

Iím not sure itís necessary to get more RAM, but RAM is usually quite cheap (full disclaimer I havenít researched the price difference between the different RAM amounts versions of the Pi 4) and once you own the board if you find later on you could benefit from more RAM you typically have to buy a whole new Pi...
Oct 14, 2020, 11:01 AM
Registered User
At the moment, more RAM is only useful for the recording stuff. So if you have more RAM, you can record longer videos. But according to Stephen, this will change in future, as he will implement direct saving to USB or SD memory.
Oct 20, 2020, 08:23 PM
Hot glue will fix anything!
Uksteve's Avatar
Hi, totally new to this and still reading up and researching on what gear I'd need but have a question about the WiFi modules and the regular RX onboard please.

I know that it is possible to control the craft through the link and a traditional RX is not 'needed' but what's the score if you choose to run with a regular RX and have 800mw WiFi , will it walk all over the signal to the RX or is that not an issue, I am running power in the watts on my current 2.4 control so the signal to the RX is a lot stronger than from the average tx

Is there any reason why the ground station couldn't use one of the low powered modules which are cheap and run a 2.4ghz amplifier like I use on my current 2.4ghz control?

I also have very lightweight but less powerful 2.4 amps kicking about which could go on the air unit , all the amps I have are bi directional and support telemetry and the decent ones have pre amps in them for the RX signal as well

Obviously, my 1w 868mhz r9 system and 1w 433mhz qczek wouldn't be affected, I just have so many 2.4 RX's that I try to use them instead of buying more long range RX's as I get several miles and regular cloud surfing on my current 2.4 setup

I'm planning on using the zero for the air unit because of cost but more so, the weight and size, the github wiki says the zero is no longer compatible as a ground unit, is that cast in stone or is it possible to run an older version to get in the air initially for minimum cost to see if its something I like and then later upgrade to a pi 2 or 3 and then the zero could be used as a second air unit?


Thanks, Steve.
Last edited by Uksteve; Oct 20, 2020 at 09:09 PM.
Oct 22, 2020, 03:36 PM
Complicating things
Karamba's Avatar
Quote:
the github wiki says the zero is no longer compatible as a ground unit, is that cast in stone or is it possible to run an older version to get in the air initially
Pi3a+ is about the minimum you need for ground.
Pi3B+ suggested
if yuoe wifi is going to be 2.4, use 433/900 for RC or use RC over OpenHD
Oct 22, 2020, 03:52 PM
Registered User
The RPi4 CM looks like it would be great to use on the air side. Has anyone tried using one with OpenHD yet?

https://www.raspberrypi.org/blog/ras...pute-module-4/
Oct 22, 2020, 04:48 PM
Registered User
Quote:
Originally Posted by InsipidMonkey
The RPi4 CM looks like it would be great to use on the air side. Has anyone tried using one with OpenHD yet?

https://www.raspberrypi.org/blog/ras...pute-module-4/
It looks like a lot of work to break out the USB, UART and CSI, not to sure it would be much weight saving compared with a stripped down RPI4B

Could be great though and on the ground side itís small enough almost to cram into a goggle module bay.
Oct 25, 2020, 01:56 AM
Registered User
Quote:
Originally Posted by PetruSoroaga
Still, everything is shielded (both air and ground): network cards, raspberry pi and the USB cables between network cards an RPI are the type where ground is is a shield (kind of like coaxial cable, but for audio mainly). And, ofcourse, diversity on the RX side (2 cards).
Sometimes i have a lot dropped video frames. From the shielding, I only have the screen of USB cable soldered to the housing of the network card. I don't really understand how to screen everything else. If it's not difficult for you, could you upload a photo of your system, or a diagram of how to properly screen RPI network cards and cable from the camera please?
Oct 25, 2020, 01:13 PM
www.petrusoroaga.com
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I don't have a picture handy, but basically you cover each board with electrical tape or any kind of insulating tape, then aluminum foil, then electrical tape again. Cover as much as possible and the aluminum foil patches should overlap to conduct electricity. Basically, you are trying to do a faraday cage. I do not do this for the camera cable, I did not had issues with that (if everything else is shielded. If you want to get fancy (at least on the ground side), build a box out of DIY circuit board sheet (the kind that has a continuous copper sheet on it (not ones with holes).
Oct 26, 2020, 02:31 AM
Registered User
Don't forget to connect the foil to the negative lead. This helps heaps with the shielding effect.
Oct 26, 2020, 12:24 PM
www.petrusoroaga.com
PetruSoroaga's Avatar
Quote:
Originally Posted by led lighter
Don't forget to connect the foil to the negative lead. This helps heaps with the shielding effect.
Frankly, I do not do that. And I see no reason for it (electric/physics laws). A faraday cage is a faraday cage, right? No need for a connection to a 'ground'.
My concern is that connecting the negative rail to the shielding would result in unwanted electromagnetic radiations (the entire shielding is now an antenna basically).
Remember, negative rail is not really ground in our hobby. So the assumptions about a true ground do not apply here.
Oct 26, 2020, 07:30 PM
Registered User
mmormota's Avatar
Quote:
Frankly, I do not do that. And I see no reason for it (electric/physics laws). A faraday cage is a faraday cage, right? No need for a connection to a 'ground'.
Considering it as a "Faraday cage" is misleading and wrong. A Faraday cage is closed, this one is not, wires are going through it.

The shield has capacitive coupling to the signal wires, if it's not grounded, it becames a EM radiator as well. The whole thing is similar to a dipole antenna, one side is the ground (including the negative rail, and every other part of the circuit that is filtered by capacitors to gnd, including the positive rail etc), the other side is the unconnected shielding (driven by the inner signal wires by capacitive coupling).

Connecting the shield to the ground significantly decreases the radiation.


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