NAME

       ilowpass - Low-pass filter with integer inputs and outputs

SYNOPSIS

       loadrt ilowpass [count=N|names=name1[,name2...]]

DESCRIPTION

       While it may find other applications, this component was written to create smoother motion
       while jogging with an MPG.

       In a machine with high acceleration, a short jog can behave almost like a  step  function.
       By  putting the ilowpass component between the MPG encoder counts output and the axis jog-
       counts input, this can be smoothed.

       Choose scale conservatively so that during a single session there will never be more  than
       about  2e9/scale  pulses  seen  on  the MPG.  Choose gain according to the smoothing level
       desired.  Divide the axis.N.jog-scale values by scale.

FUNCTIONS

       ilowpass.N (requires a floating-point thread)
              Update the output based on the input and parameters.

PINS

       ilowpass.N.in s32 in
       ilowpass.N.out s32 out
              out tracks in*scale through a low-pass filter of gain per period.

PARAMETERS

       ilowpass.N.scale float rw (default: 1024)
              A scale factor applied to the output value of the low-pass filter.

       ilowpass.N.gain float rw (default: .5)
              Together with the period, sets the rate at which the output changes.  Useful  range
              is  between  0 and 1, with higher values causing the input value to be tracked more
              quickly.  For instance, a setting of 0.9 causes the output value to go 90%  of  the
              way towards the input value in each period.

AUTHOR

       Jeff Epler

LICENSE

       GPL