Use of the NVIDIA Jetson Nano for DATV

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F1CJN_alain
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Joined: Thu Jul 21, 2011 9:50 am

Re: Use of the NVIDIA Jetson Nano for DATV

Post by F1CJN_alain » Thu Jul 04, 2019 8:06 am

What is wrong with me ?
I had two days ago, everything right between my Portsdown and Jetson.
I lost the Jetson contact with the RPI during to a software try.
Then I re install the last Nvidia Software, last DVBSDR from GITHUB but the Jetson still does not accept the RPI commands.
The Porstdown and the Jetson, driven by SSH are ok.
The Jetson runs ok at all SR, freq , etc using SSH.
The LKV is right with VLC
My psw are right is the files.
The Jetson, LKV and Portsdown are seen through my D-link SW-D0-5G switch.
Problem, in the Portsdown Jetson menu "Shutdown Jetson and Reboot Jetson have grey color instead of green (BATC wiki).
May be my root psw ?
Have you any advice to recover ?
Alain F1CJN

G4WIM
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Joined: Thu Jan 29, 2015 8:36 pm

Re: Use of the NVIDIA Jetson Nano for DATV

Post by G4WIM » Thu Jul 04, 2019 8:30 am

Sounds very similar to my problem ie everything working fine then boom no video !

I suspect in my case it was the lkv flooding my network with broadcast messages to I did as Dave suggested and set up a dedicated network for the Jetson, rpi and LKV.

You could also try a different switch as some handle the broadcasts better than others.

This has certainly helped but now I find the LKV appears to be fussy about the HDMI signal - ie my hdmi camcorder works great but my PC as a source doesn't.

73 Tim

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Re: Use of the NVIDIA Jetson Nano for DATV

Post by G8GKQ » Thu Jul 04, 2019 8:27 pm

Hi Alain

First of all, as Tim suggests, try it without the LKV powered up. It does cause network issues (with broadcast UDP) on some switches and routers.

The fact that the buttons are greyed out simply means that the RPi is unable to ping the Jetson. So check that you can ping the Jetson from the command line on the RPi. The only thing that needs to be correct if the Jetson's IP address in the RPi for this to work.

I think that there may be some problem with recent a Jetson software update - but have not been able to test it.

Hope that helps

Dave

G4WIM
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by G4WIM » Thu Jul 04, 2019 8:42 pm

Hi guys

something else I've stumbled into might be relevant to the missing video problem.

At first I thought it was the LKV being fussy about the type of source but on closer examination using wireshark I see that the mpegts packet length from the LKV is 1358 whereas looking at the Jetson code it expects 1316 which is normal for mpegts.

So it could be two problems 1. multicast flooding issues and 2. packet length being incorrect.

#2 could explain the missing video and hit / miss sync problems.

Maybe some one else could take a look using wireshark to see what their packet length is ?

Regards Tim

g0mjw
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by g0mjw » Fri Jul 05, 2019 6:03 am

I asked before, sorry if you already answered - but which firmware are you using on the LKV373A ?

If it is working with VLC and you have updated the portsdown software, is there anything between it and the portsdown apart from the switch?

How about connecting one directly to the other with an Ethernet cable and no switch?

Finally, the check 5V supply is up to the job.

Mike

G4WIM
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by G4WIM » Fri Jul 05, 2019 10:09 am

Hi Mike,

I'm using the fw as recommended in the wiki 20160427 - I have tried direct connection with no switch - but as I mentioned above it looks as though there maybe a packet size mismatch as my LKV is sending 1358 length mpegts whereas the nano code looks as though it wants 1316.

I was hoping someone could look at their lkv stream to see what they're running packet length wise.

5V PSU is more than adequate, but will check it out for dips etc just in case.

Regards tim

g0mjw
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by g0mjw » Fri Jul 05, 2019 11:33 am

You can set several parameters with the firmware. It might be worth resetting to defaults in case anything is set up incorrectly.

Mike

G4WIM
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by G4WIM » Fri Jul 05, 2019 12:10 pm

thanks again Mike,

I should have mentioned that I had already re-flashed and reset to defaults on the LKV.
I've posted the wireshark output on Danman's LKV blog for his comments - if only to double check I'm not on a wild goose chase with respect to the packet length.


Regards Tim

g0mjw
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Re: Use of the NVIDIA Jetson Nano for DATV

Post by g0mjw » Fri Jul 05, 2019 8:35 pm

OK - strange as it just worked when I tried it. Maybe try via SSH - you will need to edit the jetson_nano script but this works for me.

Mike

G4WIM
Posts: 294
Joined: Thu Jan 29, 2015 8:36 pm

Re: Use of the NVIDIA Jetson Nano for DATV

Post by G4WIM » Fri Jul 05, 2019 9:59 pm

Hi Mike,

I've tried that and it works sometimes but complains about sync - seems to struggle to get sync on the TS.
Interestingly Danman has taken a look at my wireshark data and says:

"You are right, The IP and UDP headers seem to be off. Did you also flash encoder firmware?"

To which I replied no.

So I might be onto something and will try a different FW or reflash and or factory reset - strangely originally it did just work fine but then suddenly stopped, I'm starting to suspect the lkv packet length has changed for some bizarre reason.

Regards Tim

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