Laser Control by Spindle PWM

wl888 wrote: ok...revisited the M67 command, it will do the output value change but it appears that it is a manual input into the hal file each time a change is required.

linuxcnc.org/docs/2.7/html/gcode/m-code.html#mcode:m67

I have no idea what you mean by "manual input into the HAL"

Yep....neither do I , total brain snap....it's obviously a Gcode command....more sleep required...will look closer at M67 command and get back to you later... :blush:

Doug

see the following links

forum.linuxcnc.org/forum/49-basic-config...ed-on-one-axis#57216
if your using a cam program , then you would need to edit your post processor to use m67 instead of spindle

Thanks Cncbasher
will follow up on this .
Doug

Success.... :laugh: I can now, via g code, control the intensity of the Laser.

I started with the M67 command but later changed to the M68 command(instant), I am actually trying both to see if there is an appreciable difference.
In the M68 code guild it says:- not synchronized with movement, and they will break blending. ???What is break blending??
Is this a good reason to use the M67 over M68 or would either do??

Yes, I will be editing the Cam Post to accommodate these changes.

Am now working on putting in the DE-bounce coding into the .hal file. have found the entries necessary for this with 3 limit/home switch input pins, eg 10,11+12 the challenge i have is that i only use 1 input for the 3 axis IE pin13. all limit/homes are strung together.
i understand the coding for 3 independent limit/home switches but I'm not even sure it's possible to do this with only 1 pin as the coding seems to be axis specific eg for X axis ...debounce.0.0.out etc . Have tried several variations but no results yet. have you come across this 1 Pin setup with de-bounce before??

Thanks again for the guidance.
Doug

wl888 wrote: I started with the M67 command but later changed to the M68 command(instant), I am actually trying both to see if there is an appreciable difference.
In the M68 code guild it says:- not synchronized with movement, and they will break blending. ???What is break blending??

Movement will be smooth through an M67 command, but the change of the HAL pin value won't happen until the move starts.

If you use M68 at the beginning then they may be a burned spot at the start of the path as the laser turns on before the axis starts to move.
If you use an M67 at the end without a following move then there probably will be a burned spot at the end, because the laser won't turn off.

So, ideally you would use M67 except for the final laser-off command which should be M68.