/* * TEnergyMonitor.cpp * * Created on: 07 apr 2018 * Author: Emanuele */ #include "TEnergyMonitor.h" TEnergyMonitor::TEnergyMonitor(Serial* _pc){ pc=_pc; } //-------------------------------------------------------------------------------------- // Sets the pins to be used for voltage and current sensors //-------------------------------------------------------------------------------------- void TEnergyMonitor::voltage(PinName _inPinV, double _VCAL, double _PHASECAL) { inPinV = _inPinV; VCAL = _VCAL; PHASECAL = _PHASECAL; offsetV = ADC_COUNTS>>1; adcV = new AnalogIn(inPinV); } void TEnergyMonitor::current(PinName _inPinI, double _ICAL) { inPinI = _inPinI; ICAL = _ICAL; offsetI = ADC_COUNTS>>1; adcI = new AnalogIn(inPinI); } //-------------------------------------------------------------------------------------- // Sets the pins to be used for voltage and current sensors based on emontx pin map //-------------------------------------------------------------------------------------- //void TEnergyMonitor::voltageTX(double _VCAL, double _PHASECAL) //{ // inPinV = 2; // VCAL = _VCAL; // PHASECAL = _PHASECAL; // offsetV = ADC_COUNTS>>1; //} // //void TEnergyMonitor::currentTX(unsigned int _channel, double _ICAL) //{ // if (_channel == 1) inPinI = 3; // if (_channel == 2) inPinI = 0; // if (_channel == 3) inPinI = 1; // ICAL = _ICAL; // offsetI = ADC_COUNTS>>1; //} //-------------------------------------------------------------------------------------- // emon_calc procedure // Calculates realPower,apparentPower,powerFactor,Vrms,Irms,kWh increment // From a sample window of the mains AC voltage and current. // The Sample window length is defined by the number of half wavelengths or crossings we choose to measure. //-------------------------------------------------------------------------------------- void TEnergyMonitor::calcVI(unsigned int crossings, unsigned int timeout) { #if defined emonTxV3 int SupplyVoltage=3300; #else int SupplyVoltage = readVcc(); #endif unsigned int crossCount = 0; //Used to measure number of times threshold is crossed. unsigned int numberOfSamples = 0; //This is now incremented //------------------------------------------------------------------------------------------------------------------------- // 1) Waits for the waveform to be close to 'zero' (mid-scale adc) part in sin curve. //------------------------------------------------------------------------------------------------------------------------- bool st=false; //an indicator to exit the while loop unsigned long start = millis(); //millis()-start makes sure it doesnt get stuck in the loop if there is an error. while(st==false) //the while loop... { startV = adcV->read_u16(); //using the voltage waveform if ((startV < (ADC_COUNTS*0.55)) && (startV > (ADC_COUNTS*0.45))) st=true; //check its within range if ((millis()-start)>timeout) st = true; } //------------------------------------------------------------------------------------------------------------------------- // 2) Main measurement loop //------------------------------------------------------------------------------------------------------------------------- start = millis(); while ((crossCount < crossings) && ((millis()-start)read_u16(); //Read in raw voltage signal sampleI = adcI->read_u16(); //Read in raw current signal //----------------------------------------------------------------------------- // B) Apply digital low pass filters to extract the 2.5 V or 1.65 V dc offset, // then subtract this - signal is now centred on 0 counts. //----------------------------------------------------------------------------- offsetV = offsetV + ((sampleV-offsetV)/1024); filteredV = sampleV - offsetV; offsetI = offsetI + ((sampleI-offsetI)/1024); filteredI = sampleI - offsetI; //----------------------------------------------------------------------------- // C) Root-mean-square method voltage //----------------------------------------------------------------------------- sqV= filteredV * filteredV; //1) square voltage values sumV += sqV; //2) sum //----------------------------------------------------------------------------- // D) Root-mean-square method current //----------------------------------------------------------------------------- sqI = filteredI * filteredI; //1) square current values sumI += sqI; //2) sum //----------------------------------------------------------------------------- // E) Phase calibration //----------------------------------------------------------------------------- phaseShiftedV = lastFilteredV + PHASECAL * (filteredV - lastFilteredV); //----------------------------------------------------------------------------- // F) Instantaneous power calc //----------------------------------------------------------------------------- instP = phaseShiftedV * filteredI; //Instantaneous Power sumP +=instP; //Sum //----------------------------------------------------------------------------- // G) Find the number of times the voltage has crossed the initial voltage // - every 2 crosses we will have sampled 1 wavelength // - so this method allows us to sample an integer number of half wavelengths which increases accuracy //----------------------------------------------------------------------------- lastVCross = checkVCross; if (sampleV > startV) checkVCross = true; else checkVCross = false; if (numberOfSamples==1) lastVCross = checkVCross; if (lastVCross != checkVCross) crossCount++; } //------------------------------------------------------------------------------------------------------------------------- // 3) Post loop calculations //------------------------------------------------------------------------------------------------------------------------- //Calculation of the root of the mean of the voltage and current squared (rms) //Calibration coefficients applied. double V_RATIO = VCAL *((SupplyVoltage/1000.0) / (ADC_COUNTS)); Vrms = V_RATIO * sqrt(sumV / numberOfSamples); double I_RATIO = ICAL *((SupplyVoltage/1000.0) / (ADC_COUNTS)); Irms = I_RATIO * sqrt(sumI / numberOfSamples); //Calculation power values realPower = V_RATIO * I_RATIO * sumP / numberOfSamples; apparentPower = Vrms * Irms; powerFactor=realPower / apparentPower; //Reset accumulators sumV = 0; sumI = 0; sumP = 0; //-------------------------------------------------------------------------------------- } //-------------------------------------------------------------------------------------- double TEnergyMonitor::calcIrms(unsigned int timeout) { #if defined emonTxV3 int SupplyVoltage=3300; #else int SupplyVoltage = readVcc(); #endif //Reset accumulators sumI = 0; unsigned long NumberOfSamples=0; unsigned long start=millis(); while ((millis()-start)read_u16(); // Digital low pass filter extracts the 2.5 V or 1.65 V dc offset, // then subtract this - signal is now centered on 0 counts. offsetI = (offsetI + (sampleI-offsetI)/1024); filteredI = sampleI - offsetI; // Root-mean-square method current // 1) square current values sqI = filteredI * filteredI; // 2) sum sumI += sqI; NumberOfSamples++; } double I_RATIO = ICAL *((SupplyVoltage/1000.0) / (ADC_COUNTS)); Irms = I_RATIO * sqrt(sumI / NumberOfSamples); return Irms; } long TEnergyMonitor::readVcc(){ return 3340; }