Endstop Related

Microswitch Endstop

Three-Wire Microswitch Notes

Note

• FLY Motherboard Users Please Note: Three-wire microswitch endstop switches cannot be directly connected to the FLY motherboard, as the endstop interface on the motherboard already provides a 5V power supply. Direct connection will cause a 5V short circuit, potentially damaging the motherboard, host computer, drivers, and other equipment!

• Solution
  • Cut the 5V wire: Cut the 5V wire (usually red, but please confirm by actual color) in the XH2.54 terminal of the three-wire endstop switch, and wrap it with insulating tape to prevent short circuits.

Microswitch Wiring Method

Notes

• Strongly Recommended: Use the normally closed (NC) contact (to prevent crashes in case of disconnection)

• Wiring Requirements:

Motherboard Terminal	Function	Connection Requirement
5V	Power	🔌 Leave unconnected
GND	Ground	✅ Must be connected
S	Signal	✅ Must be connected

• Testing Steps:

1. Set multimeter to continuity test mode (beep icon)

2. Test microswitch:

   • Not Pressed: Continuity between NC and common terminal (beeper sounds)
   • Pressed: Open circuit between NC and common terminal (no sound)

3. If results are reversed:

   • Check if normally open (NO) contact was mistakenly used
   • Check for poor contact
   

Configuration Instructions

• Pull-up Resistor Requirement:

  • Most printers require enabling the pull-up resistor, which requires adding the ^ symbol before the pin name

• Normally Closed (NC) Endstop Configuration:

  • When using a normally closed (NC) endstop, add the ! symbol

• Below is a sample configuration

  [stepper_x]
  endstop_pin: ^!PD9

TAP

Wiring Instructions

Note

• This tutorial demonstrates using the BL-Touch interface on the SHT36-V2
• Some TAP devices support 12V or 24V, but it is recommended to use 5V for safety
• The center signal pin of the BL-Touch cannot be used as an endstop pin!!!

Motherboard Terminal	Function	Connection Requirement
5V	Power	✅ Must be connected
GND	Ground	✅ Must be connected
S	Signal	✅ Must be connected

Sample Configuration

• Pull-up Resistor Requirement:
• Most printers require enabling the pull-up resistor, which requires adding the ^ symbol before the pin name

[stepper_z]
endstop_pin: probe:z_virtual_endstop
# position_endstop: -0.5        

[probe]
pin: ^sht36:PC15             # Signal interface
x_offset: 0                  # X-axis - Offset from nozzle
y_offset: 0                  # Y-axis - Offset from nozzle
#z_offset: 0                 # Z-axis - Offset from nozzle
speed: 3.0                   # Leveling speed
lift_speed: 5                # Probe lifting speed
samples: 3                   # Number of samples
samples_result: median       # Value selection method (median by default)
sample_retract_dist: 3.0     # Retract distance during leveling
samples_tolerance: 0.075     # Sampling tolerance (Note: too small a value may increase sampling count)
samples_tolerance_retries: 3 # Retries when exceeding tolerance
activate_gcode:
    {% set PROBE_TEMP = 150 %}
    {% set MAX_TEMP = PROBE_TEMP + 5 %}
    {% set ACTUAL_TEMP = printer.extruder.temperature %}
    {% set TARGET_TEMP = printer.extruder.target %}

    {% if TARGET_TEMP > PROBE_TEMP %}
        { action_respond_info('Extruder temperature target of %.1fC is too high, lowering to %.1fC' % (TARGET_TEMP, PROBE_TEMP)) }
        M106 S255
        M109 S{ PROBE_TEMP }
        M106 S26
    {% else %}
        # Temperature target is already low enough, but nozzle may still be too hot.
        {% if ACTUAL_TEMP > MAX_TEMP %}
            { action_respond_info('Extruder temperature %.1fC is still too high, waiting until below %.1fC' % (ACTUAL_TEMP, MAX_TEMP)) }
            TEMPERATURE_WAIT SENSOR=extruder MAXIMUM={ MAX_TEMP }
        {% endif %}
    {% endif %}

Optical Endstop

Note

• This tutorial uses the EE-SX670WR
• Sensor Type: NPN Normally Closed Switch
• Power the photoelectric switch with 5V
• For voltages exceeding 5V, refer to the proximity switch tutorial below for 12V or 24V usage

Wiring Instructions

Motherboard Terminal	Function	Connection Requirement
5V	Power	✅ Must be connected
GND	Ground	✅ Must be connected
S	Signal	✅ Must be connected

• EE-SX670WR wiring instructions

• It is recommended to connect the normally closed terminal to the blue wire (GND)!

  Photoelectric Switch	Function	Connection Requirement
  Brown	Power	✅ Must be connected
  Blue	Ground	✅ Must be connected
  Black	Signal	✅ Must be connected
  Pink	Normally Closed	Use with GND connected

  

Configuration Instructions

• Pull-up Resistor Requirement:

• Most printers require enabling the pull-up resistor, which requires adding the ^ symbol before the pin name

• Below is a sample configuration

[stepper_x]
endstop_pin: ^PD9

Proximity Switch

Important Note

• Using Omron proximity switch TL-Q5MC2-Z as an example, please note before operation:
• Sensor Type: NPN Normally Closed Switch
• Required Component: You need to purchase a BAT85 diode separately

Wiring Steps

1. Diode Installation

• Connect the black end of the diode (cathode) to the sensor signal wire
• Connect the other end (anode) to the motherboard signal interface

2. Insulation Treatment

• It is strongly recommended to cover exposed wire ends with heat shrink tubing or electrical tape to prevent short circuits with other devices
  

Sample Configuration

• Pull-up Resistor Requirement:
• Most printers require enabling the pull-up resistor, which requires adding the ^ symbol before the pin name
• Below is a sample configuration

[probe]
pin: ^PC0
x_offset: 0
y_offset: 25.0
z_offset: 0

Endstop Status Check

Preparation

• Prepare and perform initial inspection
• With the power safely disconnected, manually move the print head to the center of the machine before powering on.
• Open the web console and enter the following command to verify the endstop status:

QUERY_ENDSTOPS

• If wiring and configuration are correct, all endstops should show as open status.
  

Testing

• Press and hold one of the endstops (do not release), then execute the following command again:

QUERY_ENDSTOPS

• At this point, the pressed endstop status should change to TRIGGERED (for example, pressing the Y endstop should change its status from OPEN to TRIGGERED).
  

Result Interpretation

• Status Unchanged: Check if the wiring and the Pin defined in the configuration are correct.
• Unresponsive Trigger: Check if the Pin in the configuration has the ^ symbol (e.g., ^PC0), which enables pull-up. Missing it may cause triggering issues.
• Opposite Status:
  • If such a symbol exists, remove it (e.g., change ^!PD9 to ^PD9).
  • If not, try adding it (e.g., change ^PD9 to ^!PD9).