MCU 'mcu' shutdown: Scheduled pwm event will exceed max_duration laser pwm issues

[bihailantian655]

I'm using an lightburn exported marlin gcode file（m3 m4 ）, After running for about 5 seconds, an error is reported

MCU 'mcu' shutdown: Scheduled pwm event will exceed max_duration

[jakep82]

Lasers are not supported by Klipper.

#4128

[bihailantian655]

The issue is solved
Just turn this parameter up cycle_Time

[output_pin TOOL]
pin: PH6 # use your fan's pin number
pwm: True
hardware_pwm: True
cycle_time: 0.1
shutdown_value: 0
maximum_mcu_duration: 5

[Cirromulus]

Just for clarity, modifying the cycle_time should not affect the max_duration setting... If so, there is some bug worth investigating.
You should have to increase the maximum_mcu_duration value.
In master, it should be handled by klipper anyways, so I wonder how this came about. Long running moves should not affect this anymore. Only in the laser-update fork it is needed to break long-running moves into slightly-less-than-max_mcu_duration-moves.

[bihailantian655]

1 machine cpu mega2560 .

2 my firmware is compiled with the master branch， these seetings are added in the print.cfg

                      [output_pin TOOL]
                      pin: PH6    # use your fan's pin number
                      pwm: True
                      hardware_pwm: True
                      cycle_time: 0.1
                      shutdown_value: 0
                      maximum_mcu_duration: 5
                      # Default: 0 (disabled)
                      # Amount of time in which the host has to acknowledge
                      # a non-shutdown output value.
                      # Suggested value is around 5 seconds.
                      # Use a value that does not burn up your stock.
                      # Please note that during homing, your tool
                      # needs to be in default speed.
                      
                      [gcode_macro M3]
                      gcode:
                          {% set S = params.S|default(0.0)|float %}
                          SET_PIN PIN=TOOL VALUE={S / 255.0}
                      
                      [gcode_macro M4]
                      gcode:
                          {% set S = params.S|default(0.0)|float %}
                          SET_PIN PIN=TOOL VALUE={S / 255.0}
                      
                      [gcode_macro M5]
                      gcode:
                          SET_PIN PIN=TOOL VALUE=0

3 Some gcode will no longer reporte error If set cycle_time: to 0.1 （not all ）

4 the maximum value of maximum_mcu_duratio can only be set to 5

[Cirromulus]

You can disable the maximum_mcu_duration if you leave out this config element. But be aware that this disables this safety feature.
What was your cycle_time previously, before setting it to the default value of 0.1?

[bihailantian655]

thaks for your advice
the previous cycle_time: 0.001 ,