Injecting Z axis movement manually while running GCode

[fireup924]

I have a machine that is basically a 2 axis machine with the Z axis not moving while running a GCode. The Z does need to be adjusted manually while the program is running using UP/Down buttons. How can I incorporate this feature?

[terjeio]

You'll have to write a plugin that uses the new step inject functionality. Easiest will be to call the new stepper functions that sits on top of of step inject functionality as these handles acceleration/deceleration etc.

FYI I added supporting low-level code to this driver a few days ago but has not published it yet since I do not have means to test it until I am back home in early December. The new stepper functions has also been changed somewhat in yet to be published code, testing beeing done with the STM32F4xx driver.

Are you able to write and test plugin code yourself? I can provide some guidance.

[fireup924]

Acceleration/deceleration is possible if you use stepper2.c functions instead of injecting steps directly - voltage controlled THC does that.

So can I fake a voltage by converting a button press to a value (Up press -> arc_voltage = 250, Down press -> arc_voltage = 5)? and it will get me Acceleration/deceleration?

[terjeio]

Voltage mode uses feedback to keep the voltage, and thus the position above the material, constant. Faking the voltage to achieve what you want might be pretty hard...
As I wrote earlier it is better to detect both when a key is pressed and released, on pressed send a relatively large move and on key released stop it by calling st2_motor_stop().

FYI have added a bit of documentation to stepper2.c and stepper2.h in the latest commit to the subversion repo.

[fireup924]

Ok I understand now.

When I see a state change in the Up/Down inputs, I just use st2_motor_move(), st2_motor_stop() and st2_motor_run() directly.

[fireup924]

Thank you for all you help, everything is working the way I like now! :)

[terjeio]

👍

[fireup924]

[terjeio]

Email sent.
Code that uses step injection via grbl/stepper2.c functions can be found in the plasma and spindle plugins. Note: both of these has been updated, refer to the copies in the subversion repo.