Using IO port on duet 6HC to simulate limit switch

Gordon Lin

Guys, my printer uses a 3Dchameleon filament system here to achieve multi-color prints:
https://www.3dchameleon.com/

It works by using the hot end to physically bump a limit switch (and hold it down for a set amount of time) to tell the external controller what to do. I have always wanted to bypass physically bumping the limit switch by directly connecting my 6HC to the external controller, and use the 6HC to output the limit switch signal.

So for the sake of this example:
io7.out on 6HC connected to external controller
GND on 6HC connected to external controller

I was reading the documentation and I think I need to somehow use M950 to configure the pin then use M42 to set the pin high/low:

M950 P0 "io7.out"
M42 P0 S1

Is this right? I can never fully understand the examples in the documentation.

Thanks for your help in advance

Gordon

oliof

@Gordon-Lin M950 needs to be

M950 P0 C"io7.out"

To simulate the lingering at the switch, you would want to use the dwell command like this

M42 P0 S1   ; enable gpio 
G4 S1       ; wait one second 
M42 P0 S0   ; disable gpio

Gordon Lin

@oliof Thank you, this is exactly what I am after.

Kind regards,

Gordon