Z probe type LJ12A3-4-Z/BX onto RADDS board

unf0rg0tt3n

Hey Guys,

I have a Z-Probe of type: LJ12A3-4-Z/BX (12V), and I want to install it onto my RADDS board.
I figured out I need to add a resistor divider with 10KΩ and 3.3KΩ in order not to fry my board.

What I didn't figure out yet is what pins I need to use for my signal pin;
Do I need to use Z_min endstop or do I need to use Servo PMW3?
The  12VDC and GND I need to install onto the PSU or maybe I could fake extruder fan 2 which I am not using for fans.

I also want to use the autolevel function so I don't need to have my bed level spot on which is kinda cool.
So do I need to change my mechanical endstop to Z_max instead of Z_min where it is installed now (or am I wrong with this)?
I know lots of questions but youtube and lots of internet information is kinda all about Ramps and lots of marlin

Thanks in common.

Cheers,
Dennis

Repetier

z min endstop switch makes only sense with a leveled bed. If you want to allow it not leveled you need to remove it. 

You have 2 options. Use z probe as z min pin as well or use z max homing. z max homing has some benefits but homing takes a bit longer.

Z probe just needs a digital input pin. You can use any free pin, just set the right pin number. So y_max is also an option. If you use it as z min probe as well set z min endstop to same pin.

Don't know the sensor type, so why do you think you need a servo pin?

unf0rg0tt3n

Repetier said:

z min endstop switch makes only sense with a leveled bed. If you want to allow it not leveled you need to remove it. 

You have 2 options. Use z probe as z min pin as well or use z max homing. z max homing has some benefits but homing takes a bit longer.

Z probe just needs a digital input pin. You can use any free pin, just set the right pin number. So y_max is also an option. If you use it as z min probe as well set z min endstop to same pin.

Don't know the sensor type, so why do you think you need a servo pin?

So when I want to use auto bed level I need to connect to Z_max ? So how does that work exactly, when I disconnect my Z_min endstop and connect a Z_max probe using the endstop signal pin?

About the servo pin thing: http://www.akeric.com/blog/?p=4062
There is where I found it; Not many people use RADDS so this is kind of the only guy giving explanation about it.

Repetier

Ok, no idea why he used a servo pin for it, but has nothing to do with servo. As I said pins may have names but get function you assign, so any free pin works. Only important is that it is configured as input and you do not exceed 3.3V.

So you want to go with z probe only. Just unplug z min endstop and put your z probe signal pin to z min pin. Select pullup no and check if signal is ok using M114. If it is H when not triggered invert endstop.

Assign z probe also the z min pin, so firmware knows about the special condition. Also set pullup/signal same as end stop so M114 signals it right.

As a first test run G30 with a metal holding close to sensor to stop before you reach bed. That way you have time enough to reset printer if it does not stop. Do the same for z homing. When you know it works you can let it go down to bed for testing.

unf0rg0tt3n

Repetier said:

Ok, no idea why he used a servo pin for it, but has nothing to do with servo. As I said pins may have names but get function you assign, so any free pin works. Only important is that it is configured as input and you do not exceed 3.3V.

So you want to go with z probe only. Just unplug z min endstop and put your z probe signal pin to z min pin. Select pullup no and check if signal is ok using M114. If it is H when not triggered invert endstop.

Assign z probe also the z min pin, so firmware knows about the special condition. Also set pullup/signal same as end stop so M114 signals it right.

As a first test run G30 with a metal holding close to sensor to stop before you reach bed. That way you have time enough to reset printer if it does not stop. Do the same for z homing. When you know it works you can let it go down to bed for testing.

So this config should do the trick:

// ################ Endstop configuration #####################

#define ENDSTOP_PULLUP_X_MIN false  // pullup false
#define ENDSTOP_X_MIN_INVERTING false
#define MIN_HARDWARE_ENDSTOP_X false

#define ENDSTOP_PULLUP_Y_MIN true
#define ENDSTOP_Y_MIN_INVERTING true
#define MIN_HARDWARE_ENDSTOP_Y true

#define ENDSTOP_PULLUP_Z_MIN false
#define ENDSTOP_Z_MIN_INVERTING true
#define MIN_HARDWARE_ENDSTOP_Z true



// #################### Z-Probing #####################

#define FEATURE_Z_PROBE 1  //Set to enabled
#define Z_PROBE_BED_DISTANCE 10
#define Z_PROBE_PIN 18  // according to pins.h #define ORIG_Z_MIN_PIN      18
#define Z_PROBE_PULLUP 0
#define Z_PROBE_ON_HIGH 0
#define Z_PROBE_X_OFFSET 0
#define Z_PROBE_Y_OFFSET 0
#define Z_PROBE_WAIT_BEFORE_TEST 0
#define Z_PROBE_SPEED 2
#define Z_PROBE_XY_SPEED 150
#define Z_PROBE_SWITCHING_DISTANCE 1
#define Z_PROBE_REPETITIONS 1
#define Z_PROBE_HEIGHT 40
#define Z_PROBE_START_SCRIPT ""
#define Z_PROBE_FINISHED_SCRIPT ""
#define FEATURE_AUTOLEVEL 1

Just changed my original Firmware, pullup false, pin changed and autolevel on.

Repetier

Yes, looks good.

MartinH

#define Z_PROBE_X_OFFSET 0
#define Z_PROBE_Y_OFFSET 0
These need setting according to the offset distance of probe to nozzle

unf0rg0tt3n

MartinH said:

#define Z_PROBE_X_OFFSET 0
#define Z_PROBE_Y_OFFSET 0
These need setting according to the offset distance of probe to nozzle

I know, but thanks for the reminder. I still am doing the wiring and proper testing with the voltage divider to not fry my main board.

unf0rg0tt3n

MartinH said:

#define Z_PROBE_X_OFFSET 0
#define Z_PROBE_Y_OFFSET 0
These need setting according to the offset distance of probe to nozzle

Wiring worked, the offset X and Y .. are those calculated from extruder 0 or 1 or do I need to define both?

Also G30 p0 gives me error: G30 z-probe failed. How could I fix that?

Repetier

You define where 0,0 is. With 2 extruders it is normally the left extruder. Offsets are then relative to that. Only for deltas you MUST take the center of the carriage as origin.

unf0rg0tt3n

That worked. So when disabling the hardware zmin endstop as the guide says in the probe manual on the website; it won't stop anymore when it reached the bottom. Why is that?

Repetier

It also says you have to set z min end stop to the z probe sensor! as I said at 5 march. For homing it will use still z min but it must be wired to the probe and not to the z min endstop. That way we know at which position we hit the bed.

unf0rg0tt3n

I don't know what made it work but I think the software endstop did the trick because it isn't crashing in the bed. All works now!