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/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "debounce.hpp"
#include "utility.hpp"
// Returns TRUE if button state changed (after debouncing)
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bool Debounce::feed(const uint8_t bit) {
history_ = (history_ << 1) | (bit & 1);
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if (state_ == 0) {
// Previous button state was 0 (released);
// Has button been held for DEBOUNCE_COUNT ticks?
if ((history_ & DEBOUNCE_MASK) == DEBOUNCE_MASK) {
state_ = 1;
return true;
}
} else {
// Previous button state was 1 (pressed);
// Has button been released for DEBOUNCE_COUNT ticks?
if ((history_ & DEBOUNCE_MASK) == 0) {
state_ = 0;
return true;
}
}
return false;
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}