begriffs open source - cmsis-driver-bare/blob - lib/debounce.c

   1 #include <stddef.h>
   2
   3 #include "debounce.h"
   4
   5 void debounce_init(sample_state *ss,
   6         bool initial, uint32_t threshold)
   7 {
   8         ss->candidate = initial;
   9         ss->count = ss->count_reset = threshold;
  10 }
  11
  12 bool *debounce(sample_state *ss, bool val)
  13 {
  14         if (val == ss->candidate)
  15                 ss->count = ss->count_reset;
  16         else if (--ss->count == 0)
  17         {
  18                 ss->candidate = val;
  19                 ss->count = ss->count_reset;
  20                 return &ss->candidate;
  21         }
  22         return NULL;
  23 }