Mark Thompson 4d1269051b
Fixed debounce code to handle noisy switch transitions #989 (#1030)
* Fix debounce to handle noisy switch transitions

* Fix debounce to handle noisy switch transitions

* Fix debounce to handle noisy switch transitions

* Removed inline comment to see if Clang checker will be happy

* Test fix for supposed Clang formatting issue
2023-05-22 12:06:37 +12:00

47 lines
1.5 KiB
C++

/*
* 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)
bool Debounce::feed(const uint8_t bit) {
history_ = (history_ << 1) | (bit & 1);
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;
}