I recently worked with a K40 builder that needed to integrate the following:
This post shares the integration details.
WARNING: as of this date this integration has not been tested since I do not have an SKR board.
If you try this out and need help or got it to work please comment below.
Other similar work
Connecting the SKR and the LPS;
I do not recommend the method used to attach the SKR to the LPS outlined in the https://www.civade.com. The reasons are posted elsewhere in this blog.
The method that I recommend is outlined in this post. It uses one PWM signal from the smoothie to drive the LPS-L pin (or equivalent on other LPS). The LPS-L expects ground signal to turn on the laser, therefore an open-drain MOSFET is chosen as the output.
laser-power-supply-control-take-2.html
If the SKR is truly a smoothie clone then this configuration should work.
About the SKR board
About the HY-T60
Connection to SKR
This connection is for the typical K40 analog panel. Another configuration is needed if you have a digital panel. Comment if you need help with that.
The diagram below shows how to connect this type of supply including safety, test fire, interlocks, water protection, and power control pot.
On an SKR integration, the connection will be from SKR-E2 to the LPS-TL. This connects an open drain MOSFET on the SRK to the LPS-TL. When the PWM signal is true it will ground LPS-TL and turn the laser on.
SKR Equivalent circuit
This diagram shows the connection between the SRK's P2.4 pin 69, which is PWM capable, and one of the SRK's MOSFET drivers (Q1).
- The output of this MOSFET is located at E1-2.
- Do not use E1-1 as it is VBB
- Pick up the ground from DCIN-Gnd
Smoothie configuration
Below is my K40 configuration which uses a genuine smoothie boards P2.4 connection.
If the SRK is a true clone this configuration file should work.
Note: I have no way to test this as I do not have an SRK board.
Dons smoothie configuration
Note this is just the laser configuration section of the configuration file;
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## Laser module configuration
laser_module_enable true # Whether to activate the laser module at all. All configuration is
# ignored if false.
laser_module_pin 2.4 # this pin will be PWMed to control the laser. Only P2.0 - P2.5, P1.18, P1.20, P1.21, P1.23, P1.24, P1.26, P3.25, P3.26
# can be used since laser requires hardware PWM
laser_module_maximum_power .8 # this is the maximum duty cycle that will be applied to the laser
laser_module_minimum_power 0.0 # This is a value just below the minimum duty cycle that keeps the laser
# active without actually burning.
laser_module_default_power 0.3 # This is the default laser power that will be used for cuts if a power has not been specified. The value is a scale between
# the maximum and minimum power levels specified above
laser_module_pwm_period 20 # this sets the pwm frequency as the period in microseconds
switch.laserfire.enable true #
switch.laserfire.output_pin 2.5^ # connect to laser PSU fire (!^ if to active low, !v if to active high)
switch.laserfire.output_type digital #
switch.laserfire.input_on_command M3 # fire laser
switch.laserfire.input_off_command M5 # laser off
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Enjoy and please comment
Don
