From 143327bb7e9472691718572243c0f59bb0c02086 Mon Sep 17 00:00:00 2001 From: Nicolas Schodet Date: Fri, 5 Apr 2013 23:06:50 +0200 Subject: digital/io-hub/src/apbirthday: add jack filtering --- digital/io-hub/src/common-cc/debounce.cc | 46 ++++++++++++++++++++++++++++++ digital/io-hub/src/common-cc/debounce.hh | 49 ++++++++++++++++++++++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 digital/io-hub/src/common-cc/debounce.cc create mode 100644 digital/io-hub/src/common-cc/debounce.hh (limited to 'digital/io-hub/src/common-cc') 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 -- cgit v1.2.3