Endstop problem with smoothie board

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Hartmut Eger

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Nov 27, 2021, 4:52:03 AM11/27/21
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Good day,

who can help me with my PnP machine with the end stop.
I have an SS-5GL on the X, Y axes in the min.position and one SS-5GL on Z for each of the two nozzles.
I connected them with C to GND and Signal and NC to Signal (X_min 1.24, Y_min to 1.26 and Z to 1.28 and 1.29)
All end stops react to M119:
SENDING: M119
X_min: 1 Y_min: 0 Z_min: 0 pins- (XL) P1.24: 1 (YL) P1.26: 0 (ZL) P1.28: 0 (ZL) P1.29: 0

X-min was triggered.

But as soon as I move one of the axles to the end stop, nothing happens. The axes drive hard to the endstops without my smoothie board reacting.

Can somebody help me with it?

attached is the excerpt from my config file.
Endstop sction.jpg

mark maker

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Nov 27, 2021, 8:46:23 AM11/27/21
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Just some  guesses:

  1. Check how you wired the end-switch. A good design has them wired NC "normally closed", i.e. the end-switch is closed (conducting) when it is not pressed. This way a signal line break will be interpreted as "pressed" and you are alerted to the problem.  Set the polarity of the end-switch in config.txt correctly.
    https://smoothieware.org/endstops
  2. Usually, the input must be pull-up or pull-down, either physically (a resistor is present on the board), or through the MCU. If it is already done physically, remove the ^ (I don't exactly know why, but it says so in the link above). Smoothie has physical pullups on the default end-switch inputs:

    https://github.com/Smoothieware/Smoothieboard/blob/289ecaab5d17cb3c06dab00d7b116ef5af7c2f09/smoothieboard-5driver-schematic.pdf

_Mark

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Hartmut Eger

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Nov 27, 2021, 1:35:47 PM11/27/21
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Hello Mark,

Hello Mark,

many thanks for your response.
The page https://smoothieware.org/endstops i've already worked through it.

I only have one more question about the color of the limit switch wiring. Which wire is green and which is blue?
27-11-_2021_19-23-35.jpg
Since I'm not sure whether my wiring is NC on (3) X_min signal and C on (2) GND.

27-11-_2021_19-14-12.jpg
27-11-_2021_19-21-09.jpg

mark maker

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Nov 27, 2021, 3:47:48 PM11/27/21
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If in doubt, I always use a multimeter to "beep" it. That's better than any schematic.

_Mark

Hartmut Eger

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Dec 11, 2021, 3:51:32 AM12/11/21
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Thank you Mark, your firmware installed and the PnP machine homing via G28 works

Thank you for your support

Hartmut
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