NAME

       debounce - filter noisy digital inputs

SYNOPSIS

       loadrt debounce cfg=size[,size,...]

       Creates  debounce  groups with the number of filters specified by (size).  Every filter in the same group
       has the same sample rate and delay. For example cfg=2,3 creates two filter groups with 2 filters  in  the
       first group and 3 filters in the second group.

NOTE

       An  alternate  component  named  dbounce  implements  similar functionality using conventional count= and
       names= parameters.  Delay settings are implemented by a delay pin for  each  instance  instead  of  using
       filter groups.

DESCRIPTION

       The  debounce  filter  works  by  incrementing a counter whenever the input is true, and decrementing the
       counter when it is false.  If the counter decrements to zero, the output is set  false  and  the  counter
       ignores  further decrements.  If the counter increments up to a threshold, the output is set true and the
       counter ignores further increments.  If the counter is between zero and the threshold, the output retains
       its previous state.  The threshold determines the amount of filtering: a threshold of 1 does no filtering
       at all, and a threshold of N requires a signal to be present for N  samples  before  the  output  changes
       state.

FUNCTIONS

       debounce.G
              Sample all the input pins in group G and update the output pins.

PINS

       debounce.G.F.in bit in
              The F'th input pin in group G.

       debounce.G.F.out bit out
              The  F'th output pin in group G.  Reflects the last "stable" input seen on the corresponding input
              pin.

       debounce.G.delay signed rw
              Sets the amount of filtering for all pins in group G.

LinuxCNC Documentation                             2007-01-16                                        DEBOUNCE(9)