summaryrefslogtreecommitdiffhomepage
path: root/digital/io-hub/src/common-cc
diff options
context:
space:
mode:
Diffstat (limited to 'digital/io-hub/src/common-cc')
-rw-r--r--digital/io-hub/src/common-cc/debounce.cc46
-rw-r--r--digital/io-hub/src/common-cc/debounce.hh49
2 files changed, 95 insertions, 0 deletions
diff --git a/digital/io-hub/src/common-cc/debounce.cc b/digital/io-hub/src/common-cc/debounce.cc
new file mode 100644
index 00000000..1ef06282
--- /dev/null
+++ b/digital/io-hub/src/common-cc/debounce.cc
@@ -0,0 +1,46 @@
+// io-hub - Modular Input/Output. {{{
+//
+// Copyright (C) 2013 Nicolas Schodet
+//
+// APBTeam:
+// Web: http://apbteam.org/
+// Email: team AT apbteam DOT org
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+//
+// }}}
+#include "debounce.hh"
+
+Debounce::Debounce (ucoo::Io &io, int filter_depth)
+ : io_ (io), filter_depth_ (filter_depth), state_ (io.get ()), filter_ (0)
+{
+}
+
+void
+Debounce::update ()
+{
+ bool now = io_.get ();
+ // State unchanged, reset filter.
+ if (now == state_)
+ filter_ = 0;
+ // State changed, should be kept stable for filter_depth_ updates until we
+ // accept it.
+ else if (filter_++ == filter_depth_)
+ {
+ state_ = now;
+ filter_ = 0;
+ }
+}
+
diff --git a/digital/io-hub/src/common-cc/debounce.hh b/digital/io-hub/src/common-cc/debounce.hh
new file mode 100644
index 00000000..6ce0c606
--- /dev/null
+++ b/digital/io-hub/src/common-cc/debounce.hh
@@ -0,0 +1,49 @@
+#ifndef debounce_hh
+#define debounce_hh
+// io-hub - Modular Input/Output. {{{
+//
+// Copyright (C) 2013 Nicolas Schodet
+//
+// APBTeam:
+// Web: http://apbteam.org/
+// Email: team AT apbteam DOT org
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+//
+// }}}
+#include "ucoolib/intf/io.hh"
+
+/// Debounce a contact.
+class Debounce
+{
+ public:
+ /// Constructor.
+ Debounce (ucoo::Io &io, int filter_depth);
+ /// To be called at each cycle.
+ void update ();
+ /// Get filtered state.
+ bool get () const { return state_; }
+ private:
+ /// Attached input.
+ ucoo::Io &io_;
+ /// Filter depth, number of updates for which input should be stable.
+ int filter_depth_;
+ /// Current output.
+ bool state_;
+ /// Current filter counter.
+ int filter_;
+};
+
+#endif // debounce_hh