Weird Laser Mode

pauledd

@g0rg Can you double check that you attached the small board to the correct pins?
I had the same case were the laser was always on until I noticed that the pin-socket that goes into duets expansion header was attached with a offset by one pin...

g0rg

@pauledd From my understanding:
if i remove the small board, is it normal to measure 3.7v between gnd and pin8 ?

That's actually what i have , with or without the board pinned in place.

dc42

@pauledd said in Weird Laser Mode:

So then PWM value 2 is the lowest possible setting for my laser... I think I can live with that.

If you are using 255 as the maximum then the lowest is about 1.001. If you use 1.0 as the maximum then you can go as low as you like, within the limits of the resolution of the PWM generator.

pauledd

@g0rg said in Weird Laser Mode:

if i remove the small board, is it normal to measure 3.7v between gnd and pin8 ?

Well, I would expect 3.3V, I dont know why you read 3.7V ?
Yes on the bare pin I would expect High level right after boot, and the attached board should invert the logic to 0V until you issue your laser commands.

Thats the problem I had:
Peek 2020-11-27 18-25.gif

dc42

@g0rg said in Weird Laser Mode:

if i remove the small board, is it normal to measure 3.7v between gnd and pin8 ?

It should be 3.3V.

g0rg

@pauledd You got it ! Same idiot issue. I put the board on the right pins and it works now.
Sometimes more than 2 eyes and a good reactive forum helps.
Thank you very much guys !

FelixH

So @pauledd how do you focus your laser now?

I need to do some engravings today and I haven‘t used the laser since I updated the RRF to 3.3, so I fear I will have some troubles there.

I understand the safety issue behind, but I used to use the laser at 1% power to align it with my work and also focus. I don‘t understand how I am supposed to do it now if the laser can only be ON while moving…

Phaedrux

@felixh said in Weird Laser Mode:

I don‘t understand how I am supposed to do it now if the laser can only be ON while moving…

I'm not sure either, but maybe a work around could be to start a move with the laser on with a very very slow feed rate so that it barely actually moves?

FelixH

@phaedrux following the original poster's suggestion, I prepared two macros for that:

FOCUS LASER ON

M106 P2 S255  ; turn on laser's 12v PSU


M451   ; disable Laser Mode

M950 F3 C"nil"     

M950 F3 C"!exp.heater3" Q1000   ; assign laser pin to a free fan Numbe

M106 P3 S0.001 ; enable laser with 1% power 


; do the focusing stuff

FOCUS LASER OFF

M106 P3 S0 ; disable laser


M950 F3 C"nil" ; free heater3 again for use in laser mode

M106 P2 S0  ; turn on laser's 12v PSU

it works ok. My problem is now that I have to do the focusing BEFORE switching to Laser mode with:

M452 C"!exp.heater3" S1 F200

If I have done something in laser mode and I have to refocus or pinpoint another work origin, even if I switch to CNC mode it throws an error telling me that the pin "exp.heather3" is occupied (or assigned, I don't remember). So, how do "unassign" the pin when I switch from Laser mode to CNC mode?

Sincerely I can understand the safety concerns behind not being able to use M3 while not moving, but at the end of the day, if I have a laser I have to be able to set it onto the correct origin and also focus it. Even I am not able to do that with a M3 command, I have been able to do find a workaround.
I think this is an issue it should be addressed. It makes working with a laser cumbersome and overly complicated if you are not use to tinker with the RRF3 environment. Maybe a solution would be limit the power output of the M3 command to 1% when stationary? Just an idea...

FelixH

well, just as usual after I posted something I myself come up with an improvement...

I changed the macros as follows:

Laser focus ON

M106 P2 S255  ; turn on laser's 12v PSU

 
M453   ; Enable CNC Mode

M950 P0 C"!exp.heater3" Q1000   ; assign laser pin to a pin number

M42 P0 S0.01  ; set 1% PWM on GPIO port 0


; do the focusing stuff

Laser Focus OFF

M42 P0 S0 ; disable laser

M950 P0 C"nil" ; free heater3 again for use in laser mode

M106 P2 S0  ; turn on laser's 12v PSU

And I changed my "switch to CNC macro to:

M5 
M106 P2 S0  ; turn off 12v PSU
M452 C"nil" ; free "exp.heater3" pin
M453 ; Put the machine into CNC Mode

M550 P"WorkBee CNC Machine" ; Set machine name

in which I added the M452 C"nil" line.

This seems to work, although when I go back to CNC mode the console throws a red warning:

Error: DueX fan or GPIO pins may not be used to control lasers

but well, it looks like I will have to live with it. On a positive side, I think that the M42 command lets me control the power of the laser somehow better. Yesterday I used it "the old way" with a Fan port and even a M106 P3 S0.001 would start burning the plywood after a couple of seconds.

Phaedrux

@felixh said in Weird Laser Mode:

So, how do "unassign" the pin when I switch from Laser mode to CNC mode?

M452 C"nil" should free the pin.

Which I see you found already.

@felixh said in Weird Laser Mode:

Sincerely I can understand the safety concerns behind not being able to use M3 while not moving

I'm not sure on that either. @dc42 could say more?

o_lampe

@felixh
I guess you get this error message, because RRF doesn't register the C"nil" part.
It just recognizes you are using M452 in CNC mode... @dc42 I guess, this could be sorted out?

Felix, would it be possible to go through a real tool change? Then you could free the laser pin in tfree.g* while you are still in laser mode.

FelixH

@o_lampe

Felix, would it be possible to go through a real tool change? Then you could free the laser pin in tfree.g* while you are still in laser mode.

I will try it when I get back home, yeah. Thanks!

o_lampe

@felixh
I figured out a simpler method to fire the laser without moving.
No need for CNC mode switches and re-assigning pins:

G1 E10 F60 Snnn   ; requires a virtual extruder in config and M302 P1 to allow cold extrusion

With this simple line your laser will fire up for 10sec. Tested with RRF3.3

FelixH

@o_lampe sounds great and simple, but am I right to think you are working with a 3D printer setup?

o_lampe

@felixh
The controller was in 'Laser mode' when I tested it, but there was also an extruder tool config. It's not necessary to have a stepper or thermistor connected, just a virtual config.