Problem with stepper motor controller

Discussion in 'The Projects Forum' started by sakeynes, Apr 29, 2012.

  1. sakeynes

    Thread Starter New Member

    Apr 29, 2012
    Hi all,
    BACKGROUND-I am making a scotch mount, also called a barn door mount, for astro-photography. I need to drive a motor at a fixed speed, but I will have to tune it to that speed very carefully, and then set it and never adjust again. Not much torque is required.
    I thought a stepper motor would be a good way to go, as opposed to a DC motor with some kind of feedback for rate control.
    I bought a cheap controller off eBay exactly (as far as I can tell) the same as this:
    Has anyone had experience with this controller? It sells cheaply on eBay and all the instructions on it's use seem to be consistent. I only want to use it in button control mode if possible.
    PROBLEM - When I run it in button control mode, the INC and DEC buttons do increase and decrease the speed, but they also reverse the direction. Ie. INC will increase the clockwise rotational speed, but when I hit DEC the motor changes to anti-clockwise, at a slightly slower rate. This is hopeless! Anyone know how to keep it moving in only one direction while making speed adjustments? I have Jumper JP1 on, jumper JP2 off, as per instructions.
    Thanks in advance
  2. bertus


    Apr 5, 2008

    By reading the description, I would use mode 1:

    In mode 1 the speed can be controlled using external pulses (JP1 removed).
    These can be generated by an NE555.
    If you want higher accuracy a x-tal controlled oscillator can be used.
    The direction an run/stop can be done using switches on the respective inputs.
    (see your datasheet for more info).

    Last edited: Apr 29, 2012
  3. sakeynes

    Thread Starter New Member

    Apr 29, 2012
    Thanks Bertus.
    I'd really rather stay away from using external control if I can. The controller just doesn't seem to be operating as advertised. Changing directions when the speed is increased or decreased doesn't make any sense! Has anyone used this controller before in button-control mode and had it work just fine?