Portsdown 2018 Stretch Software News

[G8GKQ]

Hi Paul

Short answer, no.

Long answer: It would need code changes in at least 2 places: avc2ts.cpp (for H264 encoding) and in a.sh in the ffmpeg calls for the camera (for MPEG-2 encoding). There might also need to be some changes where the camera image is displayed on the touchscreen.

The old avc2ts.cpp used to have an internal switch for inversion, but I have not looked at the newer (current) version for this. For ffmpeg you can put something in the -vf string to invert the image, but I haven't played with it.

These changes would be over-written by every software update.

Suggest that you buy a longer ribbon cable.....

Dave

[g7ntg]

Hi - there are several of us here in Kettering using the new software with great results. We are also using the Pluto successfullly with linears at 1255 and other frequencies. I see your eventual aim is to include the Pluto in the software and we are looking forward to this as to control a pluto without a PC or Laptop would be really useful!

[F4DVK]

HI Dave,
I just noticed this line in install.sh for the french installation:

sed -i 's/^menulanguage.*/menulanguage=fr/' rpidatvconfig.txt

I think it should be changed to:

sed -i 's/^menulanguage.*/menulanguage=fr/' portsdown_config.txt

This is probably a forgetting.
Tell me if that's right?

Thank you,
Stephane.

[G8GKQ]

Stephane

You are right. I will try to get the fix into the next release!

Thanks

Dave

[F4DVK]

Hi Dave,

A friend pointed out to me a problem with the receiver.

During long use, this one plants. After restarting, the portsdown program no longer launches (blocked in the Portsdown image).
I managed to reproduce this bug, and I found the source.

This is the fifo.iq file which is very large and takes up all the space of the SD card.

This problem was not present with the first rpidatv version.

Thank you.
Stephane.

[G8GKQ]

Stephane

The cure I first tried did not work. Is your friend selecting receive from the console or the touchscreen?

Dave, G8GKQ

[F4DVK]

He selects it from the touchscreen.

[G8GKQ]

New Portsdown Stretch Software Release 201811300

This major release introduces full support for the LimeSDR Mini and LimeSDR USB devices as alternatives to the Portsdown Filter-modulator board. Although the Portsdown struggles to drive the LimeSDR at Symbol Rates above 1MS (due to the RPi's limited CPU processing speed), the transmitted spectrum at 1MS and below is much cleaner than the Portsdown Filter-modulator board. Additionally, DVB-S2 transmission modes are available when using the LimeSDR. So, if you want high SR (>1MS), the filter-modulator board remains the best solution.

Note that the performance with LimeSDR is not as good at 2MS and 4MS as with the previous software release (201811170) - an unavoidable trade-off. The LimeSDR firmware required (and loaded) for this release is the same as that required for DATV Express 1.25lp12.

Details of the Lime functionality are published here https://wiki.batc.org.uk/Using_LimeSDR_with_Portsdown with further information in CQ-TV 262.

The full contents of this release include:

• Lime install by default
• Lime upsampling and GPIO support
• Correct Streamer watchdog permissions
• Correct high-side LO transverter frequency calculations

Dave
G8GKQ

[radiogareth]

Works well for me although I don't get any output from my Lime SDR above 2.0GHz. Is there any way to configure the lime to try a different Hi port I wonder. Not urgent....
Mine sent the animated test card smoothly at SR2000 but fell over at 4000. Running a RPI3B+ which I guess helps a bit.
Great stuff
Gareth, G4XAT

[G8GKQ]

Hi Gareth

If you have a LimeSDR USB, the output is switched to the TX1Hi port above 2 GHz. You should get about -6 dBm at 2.4 GHz. On the LimeSDR Mini, the internal circuitry is switched so that the output is maintained above 2 GHz.

Dave