My Pi Journey, the next generation

[VK5PJ]

Hi,
well it is time for a new PI here as I always felt the PI 3B was a little slow doing decodes on the FT8 mode of WSJT-X and now with FT4 around, I felt I needed more horsepower to get the job done.
Went ahead with the purchase of a Raspberry PI 4 from the same supplier as before (Little Bird Computers) but this time I have opted for the active cooling heat sink option as the temp's in my shack get quite nasty in summer (part of an industrial shed used for our horse stables), have just plugged it in and am writing this part on the PI as it is doing an upgrade in the background.
The case / cooling is https://www.littlebird.com.au/products/ ... berry-pi-4
Could not help my self, have already downloaded the WSJT-X package from here: https://physics.princeton.edu/pulsar/K1JT/wsjtx.html and once downloaded went ahead and run the .deb (https://physics.princeton.edu/pulsar/K1 ... _armhf.deb) file from within the browser. Smooth as can be, just one prompt for priveleges and away it went. Now it did put the shortcut into an odd place in the menu (Sound & Video) but you can right click on it and select Add to Desktop which I did.

Okay, so much to do with the Raspberry 4, I am sure time will get away from me, I know a few readers had terrible problems coming to grips with the PI but I find them so much fun for what they can do.

More soon.

[VK5PJ]

Okay, 1st quirk,
it would seem the release of the Raspbian O/S on my SD card is a little old and when I try to upgrade I get this lovely message

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pi@raspberrypi:~ $ sudo apt-get update
Get:1 http://raspbian.raspberrypi.org/raspbian buster InRelease [15.0 kB]
Hit:2 http://archive.raspberrypi.org/debian buster InRelease
Reading package lists... Done                             
[b]E: Repository 'http://raspbian.raspberrypi.org/raspbian buster InRelease' changed its 'Suite' value from 'testing' to 'stable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.[/b]

The answer is to run this command "sudo apt update" to update the updater package, yes I know, it seems silly but you can not argue with those who built the O/S

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pi@raspberrypi:~ $ sudo apt update
Hit:1 http://archive.raspberrypi.org/debian buster InRelease
Get:2 http://raspbian.raspberrypi.org/raspbian buster InRelease [15.0 kB]
E: Repository 'http://raspbian.raspberrypi.org/raspbian buster InRelease' changed its 'Suite' value from 'testing' to 'stable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
Do you want to accept these changes and continue updating from this repository? [y/N] y

Once this is completed you can go back to do a normal upgrade, then a normal update (yes they are fdifferent animals)

sudo apt-get upgrade

sudo apt-get update

[VK5PJ]

Oh dear, I knew there was a reason why I hate FANS, one of the pair of micro small fans on the PI-4 cooler I linked in the original posting has become noisy and just 4 hours of service, back to passive cooling for now.

[VK5PJ]

Wow,
how things change between linux version, went to use the graphical file manager today and it just exits after opening (display is there for less than a second).
Grrr I quite like the inbuilt file manager, so Mr Google reveals I am not alone.

https://www.raspberrypi.org/forums/view ... p?t=256923

Answer suggested is:

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sudo apt-get update
sudo apt-get full-upgrade
sudo ap-get autoremove
sudo apt-get reboot

Running this at present , will see if it is indeed the answer, then see if I can copy the WSJT config file from the old PI to the new one, which would save me some setup time.

[VK5PJ]

my next challenge has been that the screen resolution via VNC on remote connections is very low. I had not experienced this on my earlier PI's so was a little frustrated that the new PI 4 popped up this problem but it would seem it is not all that un common
https://www.raspberrypi.org/forums/view ... p?t=200196

In essence you have to edit a config file, so you need to edit /boot/config.txt with a suitable text editor. i used NANO to do this: $ sudo nano /boot/config.txt

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# uncomment to force a console size. By default it will be display's size minus
# overscan.
framebuffer_width=1900
framebuffer_height=1024

once edited it is best to reboot the PI: $ sudo reboot now

Now when I connect via VNC I get a moreworkable desktop display so I can see what 50 MHz WSPR has been up to during the day.

[VK5PJ]

Okay time for an SDR on the PI-4

RTL-SDR RTL2382U 0.5 PPM TCXO Software Defined Radio Receiver Dongle (on ebay for $28) has SMA antenna connector and reasonably good stability with the TXCO. I have used this for monitoring FT8 on 50.313 for weeks at a time, with no need to fiddle the frequency to decode signals.

Was not sure what software to try this time but settled on Gqrx for a trial... found a good run through on how to get going, which includes some great help on setting up PULSE audio and some virtual audio connections on this web site
https://www.rtl-sdr.com/tutorial-settin ... berry-pi-3

While the site makes reference to PI 3 I was able to cherry pick what I needed.

Add/Remove software: Gqrx (the SDR package)

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$ sudo apt-get install pulseaudio pavucontrol mplayer -y    (Pulse Audio and its control app)

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$ sudo leafpad /etc/pulse/default.pa

Edit the conffig file for Pulse audio, Add the following lines to the end of the file:

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load-module module-null-sink sink_name=Virtual0 sink_properties=device.description="Virtual0"
load-module module-null-sink sink_name=Virtual1 sink_properties=device.description="Virtual1"

We also recommend disabling PulseAudio logging, as this seems to be a large user of CPU cycles.

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$sudo leafpad /etc/pulse/daemon.conf

Now find "log-level" and change it to "log-level = error". Remove the semi-colon on the log-level line too. Save and exit.

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; log-target = auto
log-level = error
; log-meta = no

You can now reload pulseaudio either by rebooting, or running "pulseaudio -k" at a command line.

After a restart there are now some extra sound options to connect the SDR output to (Virtual0) and an option to connect WSJT-X input audio to (Virtual1).

This is not a complete start to end guide, rather some pointers on what can be done,

[VK5PJ]

Hello,
for a long time now on my PI-4 I have had problems with spots being sent to the WSPRnet.org web site from any copy of WSJT-X on my PI.

The activity page and the spots pages on wsprnet.org both showed I did not exist or had not received any data. arrghhh.

Now the popular opinion is that the Raspian O/S images have no firewall active on them so that could not be the cause or maybe not..

My symptom was like the outgoing traffic from the WSJT-X programs were being some how blocked or sent somewhere else, which seemed odd as the standard web browser and console sessions to connect to the web all ran okay.

Many months past and I updated the O/S, installed updated and no matter what I did the problem continued so where next. My next move was to actually install a firewall on the PI-4 and then apply the needed rules to see if I could monitor the traffic in the firewall logs.

So here we go

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  $ sudo apt install ufw

this installs a minimalist firewall that we can then customise. Now do not do as I did and try this from remote over VNC as I neglected to put in an allow for VNC traffic on port 5900 then rebooted the PI and wondered where it went to (oops)

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$ sudo ufw allow from any to any port 123 proto udp

Allow my the PI to get to time servers on the internet

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$ sudo ufw allow 80
$ sudo ufw allow 443

Allow internet traffic

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$ sudo ufw allow 5900

Allow VNC traffic

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$ sudo ufw status
$ sudo reboot now

This will not put the firewall into action.

I am now around 28 days in with this config and the WSPRnet site is seeing all spots from me and correctly shows my status.

Hope this might help others or be a reminder for me to do this in the future.