Paste Extruder with High/Low Limit Switches Firmware Help

I'm currently using Marlin firmware 1.0.2 as the basis of my printer. I want to use a paste extruder I've built with a couple of limit switches to ensure the stepper motor driving the extruder (essentially a syringe pump in this case) does not drive further than the extents, and break the extruder.

Does anyone have any experience with hacking in new limit switches to the Marlin firmware (or any other firmware for that matter?)

Alternatively, I was thinking of using limit switches to actually have a hard electrical stop for the motors by wiring them NC and when the switch is pressed, the voltage to the motor is cut until the extruder is reset manually. Obviously, this would not stop the software from thinking the extruder is working, unfortunately.

Any suggestions are appreciated.

Thanks!

EDIT: For further clarification, I'm using a RAMPS 1.4 generic board with a genuine Arduino Mega.

Edited 1 time(s). Last edit at 10/02/2015 11:39PM by Brutick.

You could wire the limit switch(es) in parallel with one of the printer axis limit switches and turn on the "halt on limit switch" function in the firmware. That should stop the machine, including the extruder, at its limits.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Can't believe I didn't think of that!

I'll try that out tomorrow. Thanks!