setting limits in a stepper motor system.

Discussion in 'The Projects Forum' started by adriadri, Apr 30, 2009.

  1. adriadri

    Thread Starter Member

    Apr 30, 2009
    I have this system;
    1.An encoder as pulse and direction source
    2.a driver
    3.a stepper motor that follows the encoder I move manually.
    What I need is to digitally set a ccw limit and a cw limit with the push of respective buttons on a panel,after positioning the encoder on each limit.
    In short, I need to set a range of rotation.
    No Pc at all nor physical switches (hard limits) .Then delete them to set another two limits.Also this two positions must be memorized even at power off.
    please note this must be acomplished without Pc , plc or any software involved (of course, when operating)
    Any thoughts to achieve this with an additional board to my system?
    Last edited: Apr 30, 2009
  2. SgtWookie


    Jul 17, 2007
    If you lose power in the middle of stepping the motor, you'll lose any reference to where it is.

    Your power-up sequence will need to include seeking to at least one limit.

    While you might have a uC flash into memory some values for arbitrarily set limits, the uC will need at least one method to determine what the actual stepper position is after power failure, or upon initial power-up.
  3. adriadri

    Thread Starter Member

    Apr 30, 2009
    thanks for your replies sgtwookie and Alberto!
    I found a product from TRUEMETER (a dual preset counter with eeprom) that does exactly what I need, around $140 .