Can't get Lightburn to see my laser on Ubuntu 20.04

[berainlb (PY)]

Open Console window in LightBurn. What do you see there?

[SlickRooster (Karl Kuehn)]

This is what I’m seeing in LB Console:
Waiting for connection…

Port failed to open - already in use?

Good call, I didn’t realize LB had a Console window, after googling, this looks to be a persistent issue.

[SlickRooster (Karl Kuehn)]

Ugh. Looks like re-installing an older version of LB has worked for a couple of people. Gotta love the kludgey solutions.

[berainlb (PY)]

Try one thing, try enabling “Enable DTR signal” in Edit->Device Settings.

[SlickRooster (Karl Kuehn)]

Tried, changed it to enabled, restarted the software, same console error.

[SlickRooster (Karl Kuehn)]

This looks promising:

Port Failed to Open Already in use? Error Message

I had the same error message with my home made laser running Marlin (marlin version 2.0.7.2). Reverting back to v1.2.04 worked for me to get communication with the laser working again. Neither 1.3.00 or 1.3.01 work at all, no matter what other remediation steps I tried.

I mean, in a two steps forward, 3 steps back kind of way. I’m running 1.4 currently.

[berainlb (PY)]

From what I’ve seen those solutions don’t actually address root cause. There’s typically something else going on that is tangentially addressed with the downgrade.

When did you last reboot the computer?

Also, are you familiar with terminal applications? If so, try connecting to ttyUSB0 to see if you can establish a connection.

[SlickRooster (Karl Kuehn)]

rebooted about 20 minutes ago. Will connect the port with a script, stay tuned

[SlickRooster (Karl Kuehn)]

was able to use screen to open ttyUSB0 at baud 115200

[berainlb (PY)]

What does the output show?

What parameters in screen did you use?

[SlickRooster (Karl Kuehn)]

At this point, I’m about done with this. For $60, I expect more from software. I’m going to switch to a Windows machine using LaserGRBL to verify that the laser itself actually works.

If the laser is good, I’ll remove and reinstall an older version of Lightburn on this linux machine and see if that works. I might try Lightburn on Windows, too.

Moving forward, I might continue to debug 1.4 for them, but I need to get back to making money with my tools, not fiddling.

Thanks for trying to help, though, I appreciate it.

[SlickRooster (Karl Kuehn)]

I got it!

After reading a couple of other posts, I went back and reinstalled making sure to use my regular user instead of root. Even though I added my user to tty and dialup, it was still struggling with permissions.

Got the laser to home on startup and monkeyed with the pulloff settings to make sure it’s responding to the software.

Now, I just have to learn pretty much everything else in Lightburn lol.

I’m still trying to get my head wrapped around where exactly I’m supposed to put my material when I can’t really tell where the laser comes down. Much different than CnC where I can see the cutter’s relation to the piece.

Thanks again for your help!

[berainlb (PY)]

@SlickRooster

I got it!

Nice.

@SlickRooster

I went back and reinstalled making sure to use my regular user instead of root. Even though I added my user to tty and dialup, it was still struggling with permissions.

That’s good. Although I’m curious why it wasn’t working with the root user then. Perhaps a resource conflict?

@SlickRooster

where exactly I’m supposed to put my material when I can’t really tell where the laser comes down

I assume this means your laser doesn’t have a crosshair laser. In that case you would typically use the primary laser at very low power to make it visible. Make sure you’re wearing eye protection when you do this.

1. Enable Laser Fire button in Edit->Device Settings
2. Enable “Laser on when framing” and set the appropriate power level. Start with the lowest power where you can see the laser light.
3. You can manually enable the laser in Move window by pressing the “Fire” button

[SlickRooster (Karl Kuehn)]

@berainlb

That’s good. Although I’m curious why it wasn’t working with the root user then. Perhaps a resource conflict?

I think I was running LB as my regular user from the GUI, after having installed from the command line as root in my haste to get up and running. Another prime example of “shouldn’t run under sudo -s” lol. Even after adding my regular user to the dialup and tty groups there was still something janky going on with permissions, I think. I’ve run into this type of thing before, i.e. adding my regular user to the www-data group, etc.

[SlickRooster (Karl Kuehn)]

@berainlb

I assume this means your laser doesn’t have a crosshair laser. In that case you would typically use the primary laser at very low power to make it visible. Make sure you’re wearing eye protection when you do this.

1. Enable Laser Fire button in Edit->Device Settings
2. Enable “Laser on when framing” and set the appropriate power level. Start with the lowest power where you can see the laser light.
3. You can manually enable the laser in Move window by pressing the “Fire” button

Honestly, I’m not sure on the crosshair laser, I have a lot to learn about the Longer B1. I’ll dig around for some tutorials about how to get rolling, for sure. My main focus has been on making sure that I can get connected using Linux, so today was kind of a wash for productivity, but I’m feeling free and breezy now, knowing that I’m back to the bottleneck in my learning curve is me, and not hinky software → hardware issues.

[berainlb (PY)]

@SlickRooster

Even after adding my regular user to the dialup and tty groups there was still something janky going on with permissions, I think. I’ve run into this type of thing before, i.e. adding my regular user to the www-data group, etc.

This could be true if you hadn’t rebooted post the groups being added.

@SlickRooster

not sure on the crosshair laser

Most lasers do not have crosshairs but it’s been somewhat trendy on some of the more recent models.

[SlickRooster (Karl Kuehn)]

@berainlb

This could be true if you hadn’t rebooted post the groups being added.

I re-logged and rebooted several times with no success on communicating from the software to the laser, re: the port freeing up. There was something going on there, I think. Might be something getting caught in the software when installing as root and then running as a non-superuser.

[ebarson (Ernie Barson)]

f you are still having port problems, I found the solution here (https://diode-laser-wiki.com/documentation/setting-up-the-software/)

[SlickRooster (Karl Kuehn)]

Hi Ernie, thanks. Turns out it was a permission problem after I installed as root and then tried running with my regular user. I reinstalled using the proper user, and everything sync’d right up! Been happily burning ever since.