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30 lines
725 B
30 lines
725 B
3 years ago
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#include "ADC.h"
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namespace
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{
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const int8_t calibrationNumValues = sizeof(ADC_calibration)/sizeof(ADC_calibration[0]);
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}
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ADC::ADC(int8_t gpioPin)
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: pin_(gpioPin)
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{
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}
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float ADC::read()
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{
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int16_t rawValue = analogRead(pin_);
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for(int8_t i = 1; i < calibrationNumValues; ++i)
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{
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if(i == calibrationNumValues - 1 || ADC_calibration[i].ADC_Value >= rawValue)
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{
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const auto& p = ADC_calibration[i - 1];
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const auto& n = ADC_calibration[i];
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return (float)(rawValue - p.ADC_Value) / (float)(n.ADC_Value - p.ADC_Value) * (n.MeasuredVoltage - p.MeasuredVoltage) + p.MeasuredVoltage;
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}
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}
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// This should never happen if the calibration array contains at least 2 entries
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return -std::numeric_limits<float>::max();
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}
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