I have a old chem lab CNC equipment platform (used to set up petri dishes) and it will do well for a printer. I have everything wired up and steppers moving. it comes with Omron EE-SX optical end stops. Now the problem. I have no idea how to set the code for the stops in Marlin in Configuration.h I have tried what I think are all the options of pullups and no pullups, reversing the the logic etc etc... I am sure there is a combination I have missed but I am very frustrated and figured I would ask here. When the stop is triggered the logic wire goes from 0v to 24v (it's a 24v machine and I have ramps working with it) so its a NO switch, but the logic line only goes up when attached to the pos power line to the optical endstop and not the ground line like I thought it would. So... what would you do in this circumstance to get the endstops working on this? https://reprap.org/forum/read.php?4,352984,352984#msg-352984 Wed, 16 Sep 2026 21:11:41 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?4,352984,353320#msg-353320 https://reprap.org/forum/read.php?4,352984,353320#msg-353320 behnt Reprappers Sat, 10 May 2014 11:49:25 -0400 https://reprap.org/forum/read.php?4,352984,353174#msg-353174 https://reprap.org/forum/read.php?4,352984,353174#msg-353174
Normally:
a depressed switch is actuality open cct, no voltage flows, but due to the internal pull up resistor it reads high, which is translated to triggered
a non depressed switch is actually closed cct, and pulled to 0v, this is translated to open.

With optos you need a cct, not just wired direct see eg [reprap.org]

You need to use 3 wires.. as you need gnd and +5 for power as well as the signal coming back from the device.]]> Dust Reprappers Sat, 10 May 2014 01:55:13 -0400 https://reprap.org/forum/read.php?4,352984,353172#msg-353172 https://reprap.org/forum/read.php?4,352984,353172#msg-353172
But I want to clarify before I really blow pins :) I should take the "S"ignal wire to ground? Then should I put the ground to the signal pin? Then again with S to +5v? where do I put the +5V line when I do this? I am not convinced this will work as the stop needs constant power to operate

I apologize for my newbie-ness but I guess you have to start somewhere. I totally appreciate your help Dust!

FWIW when I test the stop with my meter here is what happens:

• I attach my pos line from the meter to the +5v and to the S pin, this gives me a 0v normally and +5v when the stop is triggered.
• When I Attach my pos line from my multimeter to the S pin and ground to the ground pin I get 0v regardless of the stop being triggered.

So in my newbie head this is backwards... Make any sense to you?]]> behnt Reprappers Sat, 10 May 2014 01:33:46 -0400 https://reprap.org/forum/read.php?4,352984,353141#msg-353141 https://reprap.org/forum/read.php?4,352984,353141#msg-353141
If its dead the pin it just wont change level.

I would set it up like a 'mechanical' endstop to test.
basically wire endstop S to gnd, check with m119, then test S to +5v check with m119]]> Dust Reprappers Fri, 09 May 2014 22:29:07 -0400 https://reprap.org/forum/read.php?4,352984,353115#msg-353115 https://reprap.org/forum/read.php?4,352984,353115#msg-353115 Feeling quite dumb....

Then again how do I test if the pins are live or not? Now that I am thinking this through I powered the stop with the endstop 5v so the return should have been 5v so maybe.... crossing fingers.

If its burnt out then its the price I pay for jumping in I guess. Ill chalk this up as a learning experience...]]> behnt Reprappers Fri, 09 May 2014 19:44:07 -0400 https://reprap.org/forum/read.php?4,352984,353111#msg-353111 https://reprap.org/forum/read.php?4,352984,353111#msg-353111 Dust Reprappers Fri, 09 May 2014 19:23:59 -0400 https://reprap.org/forum/read.php?4,352984,352984#msg-352984 https://reprap.org/forum/read.php?4,352984,352984#msg-352984 Omron EE-SX optical end stops.

Now the problem. I have no idea how to set the code for the stops in Marlin in Configuration.h I have tried what I think are all the options of pullups and no pullups, reversing the the logic etc etc... I am sure there is a combination I have missed but I am very frustrated and figured I would ask here.

When the stop is triggered the logic wire goes from 0v to 24v (it's a 24v machine and I have ramps working with it) so its a NO switch, but the logic line only goes up when attached to the pos power line to the optical endstop and not the ground line like I thought it would. So... what would you do in this circumstance to get the endstops working on this?]]> behnt Reprappers Fri, 09 May 2014 14:12:37 -0400