endstop for additional U axis



  • Hey guys,

    I have a extra U axis at the expansion header: M584 X0 Y1 Z2 U5 V6 E3:4 P6
    I use an external stepper (DRV8824/8825). As you can see in the M584 command it is at Driver Number 5 (E2 on the expansion board). So the Signal wire of one of these endstop boards is wired to pin 4 (E2_Stop) of the expansion board.

    For the endstop I have this config after the driver mapping: M574 U1 S0. So when it is not hit in DWC it says "Yes" (in Machine Properties). When I hit it it says "No". So because of this I get a homeu.g failed
    When I change the M574 to M574 U1 S1. In the DWC it still says the same (No if not hit). Because of this when I try to home the U axis it is instantly homed.

    How can I inverse the endstop signal, if not by M574.

    What am I missing?

    I hope that my problem is clear
    Thanks guys


  • administrators

    Endstop inputs are allocated in the order that axes are created. So if you create just one new axis (your U axis), it will use the E0 endstop input.



  • So if I change the config to:
    M584 X0 Y1 Z2 E3:4 U5 V6 P6 it will be the E2_Stop, correct?


  • administrators

    @taconite said in endstop for additional U axis:

    So if I change the config to:
    M584 X0 Y1 Z2 E3:4 U5 V6 P6 it will be the E2_Stop, correct?

    U will use the E0 endstop, V will use the E1 endstop. M584 specifies driver numbers, not endstop numbers.



  • Sry but now I am a littel confused.
    You said "Endstop inputs are allocated in the order that axes are created" (makes total sense) and I thought M584 is specifying driver numbers and thereby creating axes.

    So how can I manipluate in which order axes are created and so allocated endstops?


  • administrators

    In firmware 2.02 and earlier, axes 0 1 2 already exist and are called X Y Z. Each axis uses its own endstop number. When you use M584 to create a new axis, that will be axis #3 and it will use endstop #3 (the one labelled E0). If you create another axis, that will be axis #4 and it will use endstop #4 aka E1 endstop.

    You can control the numbers allocated to your new axes by creating only one axis in each M584 command. If you create more than one axis in a single M584 command, the new axes will be processed in the order UVWABC.



  • @dc42 follow up question: I got an issue with the direction of the U- axis.
    in the config.g I have the following commands for the U axis
    M584 X0 Y1 Z2 U5 V6 E3:4 P6
    M569 P5 S1 --> Driver 5 (U) direction
    M574 U1 S1 --> endstop at low end und active low

    when I change the M569 P5 S1 command to S0 the direction is not changing.
    I use external drivers and everything is wired up correctly --> after homing both directions work


  • administrators

    Your M569 P5 command may contain a non-printing character (so delete it and re-type it), or there may be another M569 P5 command later in config.g.


Log in to reply