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92 lines
1.4 KiB
C++
92 lines
1.4 KiB
C++
//
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// FILE: AnalogPin.cpp
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// AUTHOR: Rob Tillaart
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// VERSION: 0.2.7
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// DATE: 2013-09-09
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// PURPOSE: wrapper for analogRead with smoothing and noise filtering
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//
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// HISTORY: see changelog
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#include "AnalogPin.h"
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AnalogPin::AnalogPin(const uint8_t pin)
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{
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_pin = pin;
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_prescale = 7;
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_alpha = 0;
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_noise = 0;
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_rawRead();
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_prevValue = _value;
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}
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void AnalogPin::setPrescaler(const uint8_t prescale)
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{
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_prescale = prescale;
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if (_prescale < 2) _prescale = 2;
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else if (_prescale > 7) _prescale = 7;
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};
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void AnalogPin::setSmoothWeight(const uint8_t alpha)
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{
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_alpha = alpha;
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if (_alpha > 31) _alpha = 31;
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};
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int AnalogPin::read(const bool twice)
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{
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if (twice) _rawRead();
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_rawRead();
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if ( (_noise == 0) || (((_value - _prevValue) & 0x7FFF) > _noise) )
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{
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_prevValue = _value;
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}
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return _prevValue;
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}
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int AnalogPin::readSmoothed()
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{
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_rawRead();
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if (_alpha > 0)
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{
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_value = _value + (_alpha * (_prevValue - _value)) / 32;
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}
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_prevValue = _value;
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return _value;
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}
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void AnalogPin::_rawRead()
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{
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#if defined(ARDUINO_ARCH_AVR)
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// remember old register value
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uint8_t ADCSRA_TMP = ADCSRA;
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ADCSRA = (ADCSRA | 0x07) & (0xF8 | _prescale);
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#elif defined(ARDUINO_ARCH_SAM)
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#else
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#endif
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_value = analogRead(_pin);
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#if defined(ARDUINO_ARCH_AVR)
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// restore register
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ADCSRA = ADCSRA_TMP;
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#elif defined(ARDUINO_ARCH_SAM)
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#else
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#endif
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}
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// -- END OF FILE --
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