Stepper Expansion Board…

  • Hi,
    Nice to see the stepper expansion boards are now available for the DuetWifi. However, I only need one additional stepper motor and have done so with the generic stepper addon boards. The problem with this is that in order to make the stepper motor work the driver enable pin needs to be sent to ground keeping the motor active all the time. It is just a small annoyance, but how can I tie the enable pin to a GPIO pin and have the firmware enable / disable the motor?

    Are servos supported on the mainboard at all or do I need the expander?

    Speaking of, does anyone want to buy my Duet (wired) board and stepper expander with about 4 hours use on it? The Wifi board came out a week later.
    I am in the USA.

  • administrators

    The enable control pin is available on the expansion header along with the step and direction pin for whichever channel you are using.

    Have a look here for information on using servos:

  • It seems I tried using that before but it did not work. I have an email somewhere from DC42 back when I first got the Duet Wifi board, he said to tie the enable pin to ground.

    I found email -

    "The current firmware assumes that all drivers are TMC2660, which means that the Enable pin will not get driven."
    This was on Sept 12, 2016

    I was using pins:
    Driver: A4988

    Expansion Port pins
    pin 1 = 5v
    pin 2 = Gnd
    pin 5 = Step
    pin 6 = Dir
    pin 7 = Enable

    Extruder did not work (had to put enable pin to ground), but I guess the enable pin works now..


  • administrators

    Ahh yes, That was the case in earlier versions of the firmware but support for the enable pin on external drivers (when a TMC is not detected) was added in a firmware upgrade.

  • Sweet!

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