More PC blues

I finally decided to rebuild the shack PC given that just about everything was going daft. I suspect this is a result of various software installs while testing new stuff that were not fully deinstalled. Yeah I know I should test in a VM…

Anyway, a complete fresh install of Ubuntu 18.04 with it formatting the disk has got the PC back to normality. Almost. Networking works again with the inbuild (un)helpful config rather than me setting it up by hand each boot via a script. And I remembered to sort Gnome out so I can get the classic view rather than the daft dock setup.

But there are two oddities… first off, the rather annoying way the screen layout changes (un)helpfully (!) when you touch the to left corner with the mouse. This can be disabled but when done so the Applications menu – the leftmost top bar menu – is no longer accessible. No amount of permutations of the toggles via gnome-tweaks will sort that.

But more annoying I have lost almost all decode highlights in wsjt-x. The only ones that work are CQ, tx and my call, nothing else. I’ve tried every combination. It’s not wsjt-x (I installed a previous version just to check, same result) and I am rather stuck with that now. It will be something obvious but I just can’t see it… hmmm.

Dead Pi

Well that’s a first for me. A dead Pi, or rather a dead SD card. I have a RPi 2 in the loft connected to a DVB-T dongle and ADSB antenna which sends data to FlightRadar 24. It’s been up there doing its thing for ages, but last night I received an email from FR24 that it had stopped sending data. As it turns out that was a very useful email because everything else was running fine.

It also logs temperatures from three 1Wire temperature sensors on the central heating pipes. As these are underneath the location of the Pi in the loft it was easier to run a wire down for the 1Wire sensors than cobble together another Pi and find a home for it away from the heat of the water cylinder and pipework. That logging and my network monitor indicated that all was apparently well and I had not noticed the FR24 status data indicated that the ADSB feed was down.

The Pi is fed via a PoE supply as I didn’t want a wall-wart and mains socket up there and it makes it easier to reboot. I logged into the Pi fine ad rebooted it from the command line to see if that cured the ADSB issue in case it had simply lost the USB-connected dongle. But it never came fully back and would not even open the ssh port. It did respond to ping. Power cycling made no difference and by this time it was midnight.

This morning I made a new SD card and got it all back working (actually better as the card is the latest o/s now and the FR24 feed also has the MLAT option built in). So, some interesting and annoying observations:

The Raspberry Pi website now has a download package for the Mac which makes creating a new SD card image a doddle. Simply download and run it, stuff a blank SD card in and choose the options and wait.

Don’t use the HDMI monitor, mouse and keyboard off your desktop PC when trying to get a Pi to work if you need to use said desktop PC at the same time! Yeah…

No matter how good your backups, if you cannot remember the name of an important file the backups are useless by themselves. D’oh.

But most importantly remember that you can mount a Pi SD card on a Linux box (and no doubt other systems) and access the files if the card still mostly works like mine did. Fortunately there were only two things on this Pi, the 1Wire code which is a five-line bash script and the FR24 package which basically installs itself from their download site. QED.

Ubuntu 18.04 LTS

I finally upgraded to 18.04, an advantage of which is I am finally rid of the Unity desktop and back to Gnome. I never ‘got’ Unity and had added there Gnome add-ons which made it Gnome-like but quirky. For some reason, the system would always launch a service process via upstart that sat there doing nothing every time I unlocked the screen… resulting in the process table filing up before I realised.

The upgrade caught me out however. For some reason it did not bring across php-mysql or the Stomp library but both were easy to put back in. I use Stomp to pull in Network Rail Open Data, something I’ve been fiddling with recently but more of that some time later on.

It also seems to default to a later CIFS protocol than my poor old backup NAS devices use meaning they would not mount, so I had to add vers=1.0 to the lines in /etc/fstab to solve that one.

Finally, until I find more, Apache would not see PHP even though PHP had been upgraded so it needed a2enmod php7.2 and a bounce of Apache. That one is particularly annoying as without it Apache merrily shows The World your PHP script as text, including of course any passwords or other niceties contained therein. Fortunately this system is not accessible from outside the house network.

Nothing else seems to be amiss, the PC still sees the SignaLink USB interface and all audio devices are still where I left them.