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ExpFilter.cpp
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ExpFilter.cpp
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/*
* This Arduino library is for filtering data using exponential filter.
* Copyright (C) 2020 Pierre-Loup Martin
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
// Exponential filter is an easy way to filter data.
// It gives about the same result as a running average, but uses much less memory !
#include "ExpFilter.h"
ExpFilter::ExpFilter(){
_filterCoef = 255;
}
void ExpFilter::begin(uint16_t value){
_lastValue = value;
}
void ExpFilter::setCoef(uint8_t value){
_filterCoef = value;
}
uint16_t ExpFilter::filter(uint16_t value){
_lastValue = _value;
_value = value;
uint32_t filter = (uint32_t)_value * _filterCoef + (uint32_t)_lastValue * (255 - _filterCoef);
filter /= 0xFF;
_value = filter;
return _value;
}
uint16_t ExpFilter::getValue(){
return _value;
}