Inductive Bed Leveling

Hello Folks,

I have installed an inductive sensor on my machine. When moving a metal object under the sensor the LED lights up. My voltage at the 'S' pin on the z endstop is 4.7 volts and 0.2 when I use a screwdriver to trigger the sensor. My ramps board is seeing this change but when I run the M119 command it always shows 'open'. I set z endstop to 'true' in marlin. My software looks good but it does not ever show 'TRIGGERED". I am baffled. Ant help would be great. Thanks

Glenn

Can you move the connection to another one of the endstop pins (all of them if necessary) and check if it shows up as triggered then? Faulty arduino pin is at least a possibility.

How have you connected the sensor to the ramps board, most of these sensors will output 12 volts(if connected to a 12 volt supply)
so they need to have a resistor voltage divider or diode fitted to protect the processor port pin.

Thanks

I will try those suggestions out. I am using a voltage divider and the board is seeing 4.7 v on the pin.

Glenn

Question: You're plugging into the Z Min pin on your RAMPS?

You're going to want to change a couple of things
Comment out:
#define ENDSTOPPULLUPS

Then under the section
#if DISABLED(ENDSTOP PULLUPS)

Uncomment the #define ENDSTOPPULLUP lines for the endstops you're using

Except
#define ENDSTOPPULLUP_ZMIN

Leave it commented out, usually with that type of probe, you need to disable the pullup

That should get it to the point where it at least changes state when you manually trigger it

Lastly if it seems to be TRIGGERED when it's not actually TRIGGERED, but OPEN when it is actually supposed to be OPEN
You may have to invert the logic by changing this line to true

#define Z_MIN_ENDSTOP_INVERTING false

It's been a while, since I played with marlin, but wasn't there a section where you had to define that z-min IS a sensor input?

I will give those suggestions a try. I am plugged into the z-endpin on the ramps. I have also selected fixed sensor. I will give it a go.

Will let you guys know.
Thanks for the help. You are a good bunch of folks

Glenn