OK now I have my Raspberry Pi 4

[fcwilt]

@Phaedrux said in OK now I have my Raspberry Pi 4:

Command lines can be a godsend. It's a very direct way of interacting with the system. It may seem a little archaic, but sometimes the old ways are still the best ways.

I knew good old DOS inside and out but I've gotten spoiled.

Frederick

[fcwilt]

Hi,

I pulled the SD card and the initial wpa_supplicant.conf was gone.

So I created another file on the card and made sure that all was correct.

The I reinstalled the card into the Pi, applied power and I was able to connect via WiFi.

So all is good - for now.

Thanks to all.

Now to figure out what the Pi is going to be good for.

Frederick

[Danal]

Excellent!

At first, it is pretty transparent that the pi even exists. DWC just works, etc. It is a little faster, and the WiFi is a little more reliable, than the old way. But mostly, it is just invisible.

First potential advantage: SSH to the pi and enter:

sudo journalctl -fu duetcontrolserver

Then do something with the printer. A bunch of log info will come out in real time. The logs you see can be handy when something odd is happening. The -f means "follow". The 'u duetcontrolserver' tells it which log. Ctl-C to stop following.

If you do not happen to be actively following the log at the moment something happens, you can

sudo journalctl -u duetcontrolserver

To dump the entire log. Which will just scroll by on the terminal. So you probably want to pipe it to a grep (search), or redirect it to a file, or whatever. One example:

sudo journalctl -u duetcontrolserver | grep -i warn

Will show only the lines containing "warn". The -i flag is "ignore case".

There's a ton of unix commands, I won't go any further, there's just lots and lots of ways to manipulate that log.

[Danal]

One other bit of trivia that may turn out to be useful someday.

On the Pi file system, directory /opt/dsf/sd/ is what the Duet 'sees' as its 'sd card'. You can manipulate any file there with full unix tools.

Also, /opt/dsf/sd/www is Linux linked to /opt/dsf/dwc2 so it is easy to have different releases or customizations of dwc and just 'point' at them to switch.

This looks like this:

pi@duet3:~ $ ls -al /opt/dsf/sd
total 24
drwxr-xr-x 6 pi pi 4096 Oct 21 19:37 .
drwxr-xr-x 7 pi pi 4096 Oct 21 19:15 ..
drwxr-xr-x 3 pi pi 4096 Oct 28 19:46 filaments
drwxr-xr-x 2 pi pi 4096 Nov  8 21:06 gcodes
drwxr-xr-x 2 pi pi 4096 Nov 11 11:54 macros
drwxr-xr-x 2 pi pi 4096 Nov 10 16:22 sys
lrwxrwxrwx 1 pi pi    7 Oct 21 19:37 www -> ../dwc2
pi@duet3:~ $

That last little -> is the link. Too long and confusing to try to document Unix symbolic link commands here... suffice it to say that little tricks like this make it VERY flexible to manipulate releases or similar when messing with the printer. Nothing you ever have to do... that very first set of "sudo apt-get update", "sudo apt-get upgrade" will always work from Duet's own distributions... just something you might want to do when experimenting or debugging.

[fcwilt]

Thanks much. Interesting stuff.

Perhaps you know that answer to this: Could a form of M587 be implemented that would make the necessary settings in Pi, so as to keep things more "Duet" like?

Frederick

[deckingman]

@fcwilt At my time of life (approaching 67) and with a mechanical engineering background, I'm really finding it hard to learn Linux in it's various guises. That's one of the reasons why I haven't yet "pressed the switch" on my RPi. I've put Manjaro on an old laptop which I intend to use as a dedicated printer laptop. But I don't know what the hell I'm doing with it and I'm on the cusp of putting an ssd in it and installing Windows instead.

I think I'm just going to have rely on these clever people to write any add ons or plug-ins that I might want to use.............

[T3P3Tony]

@fcwilt said in OK now I have my Raspberry Pi 4:

Could a form of M587 be implemented that would make the necessary settings in Pi, so as to keep things more "Duet" like?

We will implement functions through the UI (may or may not use M587) to make this easier over time. We are deliberately being cautious about thinks like networking, file permission modification etc because we don't want to introduce security flaws into the design.

[fcwilt]

@T3P3Tony said in OK now I have my Raspberry Pi 4:

We will implement functions through the UI (may or may not use M587) to make this easier over time. We are deliberately being cautious about thinks like networking, file permission modification etc because we don't want to introduce security flaws into the design.

Caution can be good.

As I had a bit of difficulty getting the WiFi to work I thought there should be a simpler way.

The initial changes to wpa_supplicant.conf (they couldn't just call it "WiFi Configuration" now could they) didn't seem to work.

The suggested utility "raspi-config" didn't work for WiFi either, although I was able to change the host name (another candidate for a M command).

The second attempt at creating wpa_supplicant.conf worked.

I would hardly call the whole procedure user friendly and certainly not "Duet Like".

But I certainly understand the whole thing is still a work in progress and I am not upset with where it is.

Frederick

[Danal]

@deckingman said: At my time of life (approaching 67) and with a mechanical engineering background...

63 and a Psych major here... we can do it !

Also, if you've been a windows user all your life, there are several basic concepts in Linux that are just "close enough looking" to windows, but VERY different even one layer under the covers, to make it more frustrating than if it were more different. If that sentence parses...

I'm not sure exactly what to suggest to break through that barrier (I had a friend that really understood both 'hold my hand', and was incredibly frustrated until that happened), so I'll see if I can find a short tutorial...

Anyway, hang in there.

[deckingman]

@Danal Actually it was me who said about approaching 67, not @fcwilt.

I also pre-date MS Windows so I understand a bit about using the command line as per DOS. And many, many years ago I taught myself to write simple programmes using BASIC in the days of the ZX81. Likewise I've bumbled about a bit with Arduino projects and before that "bit bashing" with Microchip PICs. But I've never really grasped any of it. With me it's a case of Google and YouTube to get done what I need, then I promptly forget it all. I think the thing that serves as my brain is simply full like an old HDD that needs cleaning of all the crap that's accumulated over the years - or at least it needs de-fragmenting.

[Danal]

@deckingman Obviously mine needs a good defrag as well, given that I crossed the user tags (now edited).

And my "too close, but actually different" applies even more to the DOS command line vs. the Unix command line.

[deckingman]

@Danal said in OK now I have my Raspberry Pi 4:

................And my "too close, but actually different" applies even more to the DOS command line vs. the Unix command line.

Getting too far off topic so apologies to @fcwilt but I've also been trying to learn Greek for a number of years, and "close but actually different" could be applied to the Greek Alphabet. Therefore, my excuse for not understanding Unix from now on will be "It's all Greek to me".

[fcwilt]

@deckingman said in OK now I have my Raspberry Pi 4:

Getting too far off topic

I actually like seeing how these discussions evolve and branch out. There is much that can be learned from unexpected sources.

Frederick

[Phaedrux]

I'm no stranger to the command line but it can be tricky to remember everything especially when you don't use it often so I keep some guides bookmarked.

https://raspberrytips.com/raspberry-pi-commands/