Portsdown Buster Audio Bug-fix and Contest Update

[G8GKQ]

Recent updates to the Buster operating system used by the Portsdown have caused some problems with the audio output from the LongMynd receiver. Whilst curing these problems, I have also taken the opportunity to update some of the features that allow the Portsdown to be used for handling Composite Video for 5.6 GHz drone modules. Hopefully this will encourage operators to use these modules on 5.6 GHz during the contest next weekend. There are a few other bug-fixes in this release (202006070) as well. The changes are:

• Added an audio output selector switch (RPi 3.5mm jack or USB dongle) on Menu 3. This is a duplicate of the switch in the LongMynd config Menu and redirects all audio output except the RTL-FM receiver.
• Added an audio output from the C920 WebCam Microphone when the C920 is selected for transmit using Comp Vid output mode. This means that a Portsdown with a C920 attached can be used as a camera and microphone for analog FM ATV transmitters. Remember that you will need to enable the video output (using the button on Menu 3) if you have a 7 inch screen.
• Rearranged Menu 2 with 5 "Monitor" buttons. The first enables display of the video input to an EasyCap, but without the audio being played. The image size is 540x432 (3/4 of the captured resolution) to allow display of the complete image whilst keeping the scaling reasonably easy for the RPi processor.
• The second button displays the EasyCap video and relays the audio to the selected output socket. In this case the image size is 360x288 (1/2 of the captured resolution) as the processor could not cope with any more complex scaling whilst also handling the audio.
• The third button displays the image from the PiCam. Useful for testing and setting up before transmission.
• The fourth button displays the image from the C920, but without audio. If you want audio as well, select Comp Vid as the transmit output and select the C920 from the Comp Vid transmit menu.
• The final button in the row uses omxPlayer to display (and play audio from) any stream sent to the Portsdown on port 10000. This can be used to test IPTS in, and can also be used as a remote display for a second Portsdown with LongMynd receiver in UDP mode. Just remember to change the port number in the LongMynd config. In future, I may replace this player with VLC, but further testing is required first.
• I have also fixed the bug reported by EC3DBA, so that the PTT pin 40 is now activated when transmit using LimeDVB is selected from console mode.

You can get this update in the normal way from Menu 3, Check for Update. Please report any bugs here.

Lastly - please try to use your Portsdown (or any other ATV gear - I'm not fussy) in the contest next weekend and put in an entry. It's getting more people on the air that encourages me to improve the system!

Dave, G8GKQ

[PA3GUO]

Hi Dave

I will download the new version this evening.
Thanks for the frequent updates.

We got a few people here in the region now QRV on DATV, without the Portsdown this would not have happened. Myself, I am more a satellite person, but via QO100 got interested in DATV.

Btw, I will check if the calibrate on, off etc is now correctly linked to PTT, because I had the impression I always get the same delay, even when selecting not to calibrate.

Hen, PA3GUO

[PA3GUO]

... seems in my setup IPTS input no longer receives the IPTS from ffmpeg, not during TX and not when using IPTS Monitor.
I will further dig into this

Henk

[PA3GUO]

IPTS input works (in my setup) still for 500 ks, but no longer for 250 and 333 ks.

OBS --> ffmpeg --> portsdown

Henk

[G8GKQ]

Pleased to hear that the Portsdown is promoting activity in The Netherlands.

There is very little time difference between Calibrate on/ Calibrate off. What changes is that there is no power spike with Calibrate off, but it is not a setting that I recommend - see this post: viewtopic.php?f=103&t=6696.

Dave

[G8GKQ]

Henk

I have not changed any of the code relating to processing IPTS at different SRs, so not sure why you are having problems with it at 250 and 333.

Dave

[PA3GUO]

Update:

Portsdown does transmit IPTS input also in 250 and 333ks.
It is only the IPTS monitor function that does not work (for 250 and 333)

Henk