1. mchabib

    Thread Starter New Member

    Jul 20, 2010
    hi, im working with QEI in a microcontroller for odometry in a wheelchair.
    i need some help with reading data from the position counter.
    if the position counter is reset and we move backward, what does the position counter indicate? is it an overflow error? and how will i know that the chair moved backward?
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    mchabib likes this.
  3. Jaguarjoe

    Active Member

    Apr 7, 2010
    Does your position indicator have a quadrature output? This would be two outputs, usually called "A" and "B" that are shifted 90 degrees from each other. With simple logic you can discriminate clockwise from counterclockwise rotation.
  4. mchabib

    Thread Starter New Member

    Jul 20, 2010
    yes, my indicator has 3 outputs: A, B, and X, but my problem is not with direction, it is reading the data from microcontroller. I need to know how much the wheelchair travels from reading the position counter, but the position counter resets after reaching FFFFh so data might be lost and i haven't found the solution yet,
    i would appreciate your help