Secret HDMI Portsdown?

[g8lce]

One of the accidental? things that has been done with the Portsdown 4 is to make the HDMI output to work when in remote control mode. This may be something that could be very useful. For example if you were giving a demonstration of the Portsdown 4 in a hall with two large TVs. One could have the HDMI output and the other the output of your browser with the Portsdown 4 remote screen on it.
I have a Raspberry Pi 4 in a case with just a Minitiouner Express, 5v PSU and HDMI monitor. The RPi runs the Portsdown 4 software in remote mode and is connected to my WiFi. I can use a computer or mobile phone browser (on the same LAN network) to receive DATV on the Monitor.
Why not use a Ryde you say. Well I can also connect a Pluto and transmit from the remote browser. Using vMix should allow me to send video to the Portsdown etc.
Using this approach you don't need the 7" screen (although I have another Portsdown 4 setup with the screen). The cost of this simple setup is less than the full setup with screen and extras and might be the starting point for some.
Buying a RPi kit with PSU SD card etc from the PiHut for example: https://thepihut.com/products/raspberry-pi-starter-kit
gives you all the bits you need to start before buying a Pluto and biulding a Minitiouner from the BATC shop.

Hope this gives someone a push to experiment...

Martin G8LCE

[g8lce]

Made a quick video to show this feature. I don't explain very well with Plutos mentioned instead of GoPro 11 and RPi at one point!! Just don't expect too much from this setup and if you select something that does not work you may have to unplug and restart the Portsdown. This is not supported working, just a happy accident!!

https://youtu.be/X3VfVbRIuS8

Martin G8LCE

[g8lce]

Just loaded the latest Portsdown 4 software on to a RPi 4 with no screen, just network, power supply, HDMI screen and SDRplay. The HDMI screen works and the Portsown web control allows control of it's funtions. NOT a supported feature but useful all the same!
Using it to show the received signal band veiw of GB3NQ on my input to the repeater...

portsdown-screenshot_2024-03-05T14꞉47꞉05.188Z.png (46.2 KiB) Viewed 495 times

There is a signal just below the main 1316MHz that has come up today. You can see both the 1316MHz 2MS/R and the 1318MHz 250kS/R signals

Martin G8LCE

[G8GKQ]

Yes - this is currently implemented for Portsdown receive, and for BandViewer using SDRPlay or RTL-SDR. You can switch the sound on receive to go to the HDMI audio from Menu 3.

HDMI only works if no touchscreen is connected. You can also set the HDMI definition (480p60, 720p60 or 1080p60) from Menu 3, System Config. The Portsdown display stays the same pixel size, so ends up small in the top left corner at 1080p, but received signals are displayed full screen. Note that the default is 480p60 which is incompatible with some HDMI displays.

It does not yet work for other SDRs or test equipment functions. I have not tested transmit yet.

Dave, G8GKQ

[g8lce]

Well, I just tested sending a testcard to a Pluto over my network from my laptop. The laptop ( a windows surface book 2 ) is connected via wifi while the Portsdown 4 (just a RPi 4) is wired and so is the Pluto (which is on the roof near the aerial ). I watched the returning video using the same laptop using VLC monitoring the encoder fed from a Ryde tuned to the repeater ( GB3NQ ).

So YES it does work in transmit!

Martin G8LCE