Portsdown Buster Jetson nano

[G8GKQ]

Hi Mike

Failures of the Lime Report on a LimeSDR Mini do not indicate anything about the Lime firmware. The DVB firmware sometimes passes, and the stock firmware (1.29 or 1.30) sometimes fails. Lime have recently issued a fix for this (that changes the Lime settings during the test to a configuration more likley to pass) but I have not had time to evaluate it and include it in a Portsdown build.

Coming back to the main problem, the only way to see whether a LimeSDR Mini has the Lime DVB firmware loaded is to test DATV transmissions in each mode (using a regular Portsdown 2020 or Portsdown 4). If it is done first thing after a power off/on recylcle, the programming routine is pretty reliable.

Dave

[G0LJF]

Hello Dave,

Well success - the PI cam and USB mic seem to produce both video and audio on MT in H264 and H265.
H265 is a noticeably better picture, even on a still image.

I did rewrite my Jetson SD card to make sure. I foolishly decided to change the user name from "nano" and then had a bit of a script edit session - so keeping to the exact instructions needs to be emphasized.

Last problem. No HDMI. Well I get a nice DVB signal but no video is ever demodulated or seen despite a D16 quality input (direct via a 20dB attenuator).
So, please, do I need to modify the output bit rate or any of the LVK373 settings on its web config page?

I am familiar with using OBS and matching the stream rate to the expected rate. Is this the same procedure?

I do get the stream resolved fine in VLC on my PC (even with no HDMI input there is a video message to look at).

Thanks,

Mike

[G0LJF]

Hi, Dave,

HDMI problem solved...

When initially testing the HDMI input to the Jetson (with the LKV373A), do not use the default "Please check the TX input signal" message from the LVK373A as a source EVEN THOUGH the LKV373A stream is correctly shown in VLC.

You MUST plug in a valid, working, turned on, external HDMI device or the video is not shown in Minitioune even though the Jetson is correctly transmitting a valid DATV picture and Minitioune is decoding it.

I used my GoPro Hero 3+.

73, Mike

[G8GKQ]

Hi Mike

Thanks for pointing this out. I was not aware of the issue.

Looking into it now, I see that the "Please check the TX input signal" hdmi video is not accompanied by a valid audio stream and it is this lack of audio information (it's not even silence - there's just no data) that causes the problem.

Dave, G8GKQ

[G0LJF]

Thanks for the explanation Dave,

My problem was the initial Jetson system testing after I plugged it all together - and I thought it was a good idea to use the default Video feed from the LKV373A, just to check all is working fine, but then the video is missing on demodulation/display in Minitioune.

Solved. So all UDP streams to a Jetson must have some audio data bytes, then, even if it is silence.

73, Mike

[G0LJF]

Hi, Dave, or anyone with a view,

Is it possible to simply UDP MPEG-TS from OBS straight to Jetson nano. I am assuming that the P2020 would still command the appropriate Symbol rate, encoding, and such. In other words the P2020 and nanobox system would be unchanged.

The P2020 would need to be able to set the IP and port for the OBS stream (or could simply reuse the LVK373A settings, with that device disconnected).

And the nanobox router would need that IP and Port opened up.

Am I missing some important fact?

73, Mike