Arduino Firmware For A Mendel

I have built a RepStrap in the form of a Mendel and am getting the electronics working.

I have built some stepper controllers out of some awesome Toshiba 3.5A boards and have HEXFETS to control my extruder and bed. I was looking around the latest Teacup Ramps config and noticed that they have the end stops listed as min and max. On my CNC machine all of my axis limits are wired in series as from the XYZ position it can determine where it is. Does the current firmware support this already or should I wire things up with each axis requiring two pins?

My goal is to get my RepRap running on a Teensy 2.0 board as they are very small and a third the price of an Arduino Mega. Also I have one already so why not use it.

teensy also will not have the serial delay issues many of us are having.

If you configure the same pin for all three endstops in config.h, chances are good this will work. Endstops are only used while homing, so you can even run with no endstops at all.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

if you use mechanical switches that are normally open and disable endstops during built here is another reduced pin count option that homes with 1 pin

or you could be a bit creative and code it so that after an axis homes, it backs off the home switch then homes the next switch

using 1 wire for all 3 home positions. disable the endstops during builds, and start homing by going 2mm opposite direction of switch so each axis is not at home position when starting. for example below i use 100mm distance. if using Mendel this should be changed to -200. also make sure letters are capitalized.

G0 x2 y2 z2 //start of home

G0 x-100 ;//go to home and wait till x move done
G0 x2 ;//move out of switch contact
G0 y -100; //go to home and wait till y move done
G0 y2; // move out of switch contact
G0 z -100 ;//move z to home switch and wait for z move to finish
G92 x y z e ; //set all axis to zero
G0 z5 //raise z to 5 to ensure no obstructions