SBC USB printing

o_lampe

@t3p3tony
I wonder if it's a good idea to print from a hotplug device?

chrishamm

@semi55 I haven't tried external SD card readers yet but I know USB drives can be accessed if an automount utility usbmount is configured (with uid set to dsf). If you already have an auto-mount utility configured (which would explain why SD Card 2 shows up), check if the dsf user or group can access your volume.

peterwilli

@chrishamm Hey there, thanks for replying.
I work with @semi55 in the team, so I'm replying on behalf of both of us.

Our current image runs the desktop version with DuetPi installed. The desktop is logged in as "pi" but "dsf" is used in the background.

I have unmounted the drive in question and ran the following commands to test this theory:

sudo umount D2F1-AD5F
sudo mount -o umask=777,gid=996,uid=996 /dev/sda1 /media/sd

996 is the GID/UID of "dsf".

We now get a different error where I don't know anymore what the answer to that would be:

Thanks a lot in advance

chrishamm

@peterwilli Does it help to reload DWC once it's mounted? What does

http://duet3/machine/directory/2:/

output when the drive is mounted? You may have to replace duet3 with the name or IP address of your printer.

Phaedrux

@o_lampe said in SBC USB printing:

@t3p3tony
I wonder if it's a good idea to print from a hotplug device?

Probably not, but many printers come with support for printing from USB port. SD cards are hotplug too if you pull hard enough.

peterwilli

@chrishamm said in SBC USB printing:

@peterwilli Does it help to reload DWC once it's mounted? What does

http://duet3/machine/directory/2:/

output when the drive is mounted? You may have to replace duet3 with the name or IP address of your printer.

Hi there,

With the link + mounting the drive manually for dsf we get the following error:

chrishamm

@peterwilli That error code means that DWS cannot get the file list from the requested path (even though it should have returned an HTTP error instead; I'll fix that). You could start a shell with the dsf user by running sudo -u dsf bash and then check if you can enter the mount point of the USB drive and list the files there. I suspect it's a permission problem.

peterwilli

@chrishamm Hi there

dsf@raspberrypi:/home/pi$ cd /media/sd
bash: cd: /media/sd: Permission denied

It indeed seems to break when trying to access the folder. I'm currently in the process of finding out what happened and how to fix this error.

peterwilli

Excuse me to revive this thread, but took a long break after really not being able to fix this in a reasonable amount of time without getting too crazy.

We finally solved it. The solution was:

The desktop was automounting the SD card. I finally unmounted using umount /media/pi/D2F1-AD5F
Then, I remounted using sudo mount -o rw,umask=0000 -t vfat /dev/sda1 /media/sd.
I also added dsf to the users group, but that may not be necessary.

The only thing that's left to do is making sure it still auto-mounts, but with the right permissions and configuration.

Tinchus

I have similar / same error but cant see a solution: I want to upload a gcode I have on my usb stick. I plug the USB into the raspi, and I cant see it on the DWC interface.
Im not skill on linux so, can anyobody lauch a hint on how to solve this?
My intention is only load gcode from the USB drive, not printing from it

Tinchus

I can see my USB being mounted on /media/pi/ but the interface DWC cant show me / find it..

Phaedrux

@tinchus said in SBC USB printing:

My intention is only load gcode from the USB drive, not printing from it

Then why open it from DWC? Can you copy it on the Pi side?

Tinchus

@phaedrux I have the interface, I plug in the usb drive, then I go to files > upload Gcode, shouldnt I see the usb drive in order to look for the gcode and uploaded to the PI? That is what I cant do,

Tinchus

@phaedrux It is a permissions problem because USB is mounted and I can see it on /media.
Permissions on /media are:

pi@PM8721-3:~ $ ls -all /media/
total 44
drwxr-xr-x 11 root root 4096 Jun 28 17:04 .
drwxr-xr-x 18 root root 4096 Jul 12 2021 ..
drwxr-x---+ 3 root root 4096 Jun 28 19:01 pi
lrwxrwxrwx 1 root root 4 Jun 28 17:04 usb -> usb0
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb0
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb1
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb2
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb3
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb4
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb5
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb6
drwxr-xr-x 2 root root 4096 Jun 28 17:04 usb7

The USB is mounted under /media/pi/

I change permisions on /media/pi folder to:

drwxrwxr-x+ 2 root root 4096 Jun 28 19:06 pi

Now I can see the contents of any USB I PLUG, but the interface cant do anything with it, because if I try to aluch a print from it, it says it has no roght.

How can I fix this foreever in order everytime the USB is mounted, the user and group of the USB folder is NOT root?

Phaedrux

I'm only a rudimentary linux user as well. Will have to see what @chrishamm has to say.

Tinchus

@phaedrux is there any othrr way? It was working on 3.3, may be if we replicate permissions fron that version?