M950 and Pin Names

[dc42]

If you haven't allocated the pin in M452 then it will be either free or configured as fan 2. If it is configured as fan 2 then you can free it using:

M950 F2 C"nil"

However, if you have set it up as the M452 laser control output, then I think M452 C"nil" ought to work.

[woodworksimon]

@dc42
Been trying for the last hour or so, briefly got it responding, but would give me output in laser mode using M42 without the m452 command?

Stubbornly refuses to release in either laser mode or cnc mode.
So put this macro together to try... if I am missing something, I apologise, but the comments are how I understand the logic... still not releasing!

; RRF3 fan ON test
;################### HALF POWER AT 50HZ ##################

; SET CNC MODE
M453

;======================================================
; CLEAR FAN PIN OUTPUT BUFFER
;======================================================

; release DUET pins 'fan 2' from FAN output
m950 f2 c"nil"

; DOUBLE CHECK: RELEASE MAPPED GPIO OUTPUT P4
M950 P4 C"NIL"

; PREPARE GPIOO output 'p4' ONTO FAN2 PINS AT 50HZ
m950 p4 c"fan2" Q50

; SWITCH output ON p4 at HALF power 125/255
m42 p4 s125

[dc42]

Yes that should work. If you send M950 P4 with no other parameters, what is the response?

[woodworksimon]

@dc42
'gpio port has no pin' - so why has the m950 p4 line not mapped onto fan2?

[woodworksimon]

Syntax query for the new M452 - was originally embedding it in Vectric post processor to automatically switch to laser mode. Ie "M452 P2 R50 F500" (Quotes are expected).
New M452 ie: "M452 C"fan2" R50 F500" errors because of the two sets of quotes I assume. Any thoughts as to a work around?

[dc42]

@woodworksimon said in M950 and Pin Names:

@dc42
'gpio port has no pin' - so why has the m950 p4 line not mapped onto fan2?

Probably because the original M950 P4 command failed, which is probably because the fan2 pin had already been allocated to something else.

@woodworksimon said in M950 and Pin Names:

Syntax query for the new M452 - was originally embedding it in Vectric post processor to automatically switch to laser mode. Ie "M452 P2 R50 F500" (Quotes are expected).
New M452 ie: "M452 C"fan2" R50 F500" errors because of the two sets of quotes I assume. Any thoughts as to a work around?

Does the Vectric post processor provide a means for escaping quotes within the string, for example by preceding the embedded quote with a backslash character or a second quote?

If not, then I suggest you pick an un-allocated M-code, for example M4520. Use M4520 with no parameters in your post processor script. Then create file sys/M4520.g and put the full M452 command in that.

[woodworksimon]

@dc42
done some digging - ascii codes to replace the quote marks.
Putting it all together, have I understood it correctly please:...

• ######## RepRap 3 NEW COMMANDS #########
  +---------------------------------------------------
• Command output after the header to switch LASER on
  +---------------------------------------------------
  +======================================================
• CLEAR FAN PIN OUTPUT BUFFER
• release DUET pins 'fan 2' from FAN output
  "M950 f2 c[34]nil[34]"
• DOUBLE CHECK: RELEASE MAPPED GPIO OUTPUT P4
  "M950 P4 C[34]NIL[34]"
• PREPARE GPIO output 'p4' ONTO FAN2 PINS AT 50HZ
  "M950 P4 C[34]Fan2[34] Q50"
• ====================================================================
• switch to LASER MODE on fan 2 logical pin 4, 20/255ths power @50Hz
  "M452 C[34]fan2[34] r20 Q50"
• ====================================================================
  "G0 [XH] [YH]"
• Rapid Home x&y axis

•   "G0 [ZH]"
  

• Rapid Home z axis

• commented out to prevent z movement #### WORKING

+---------------------------------------------------

• Commands output for rapid moves
  +---------------------------------------------------
  begin RAPID_MOVE
  "G0 [X] [Y] [Z]"
  +---------------------------------------------------
• Commands output for the first feed rate move
  +---------------------------------------------------
  begin FIRST_FEED_MOVE
• ####### RepRap 3 NEW COMMAND #########
  "M42 P4 S0.5"

•  Switch i/o pin P4 to 50% 
  

• ########## END RepRap 3 NEW COMMAND #######

[dc42]

That looks reasonable to me.

What is your reason for wanting to fire the laser when there is no movement, other than perhaps while testing the system initially?

[woodworksimon]

@dc42
I have to be able to adjust the focus of the laser onto the surface - may be different heights depending on job - (turn it to low power and adjust Z height), before starting to etch a design on low power or cut through.

With the cutting, as it is only a 10 watt diode, it relies on a critical focus to cut, I have heard that I should move the z down slightly during a multiple pass cut to achieve the most accurate cut. Will I have to do this manually?
I'll try out the new pp now and report back, if I may.

[dc42]

Thanks for the explanation. I can look into providing a variant of M3 that allows the laser to be turned on without movement.

@woodworksimon said in M950 and Pin Names:

With the cutting, as it is only a 10 watt diode, it relies on a critical focus to cut, I have heard that I should move the z down slightly during a multiple pass cut to achieve the most accurate cut. Will I have to do this manually?

No, if you know how much you want to move Z down each time, you can do it in GCode, either by using relative motion commands or by using babystepping to adjust the focus in the first place..

[woodworksimon]

@dc42
Thank you so much!
For the first time I feel I have understanding of the revised gcode and post processor and therefore full control of my laser - really only now for the first time.
Tomorrow will be busy. Thanks again

[DeltaCon]

@dc42 said in M950 and Pin Names:

I can look into providing a variant of M3 that allows the laser to be turned on without movement.

I think that would be welcomed by a lot of diode laser module owners! (like me).

[XSIVSPD]

@dc42 this would be an amazing addition if it's possible!

[Denis]

@dc42 Is there any progress on this topic? I have a manual Z-axis adjustment and would like to be able to focus. I still haven't figured out how to do it. When using the G1 command, the laser goes out after a while, you have to run the G1 commands every time. Is there a solution to this problem?

[dc42]

@Denis please start a new thread for this request, because it has nothing to do with the title of this one.