// ----------------------------------------------------------------------------- // Eergy monitor sensor // ----------------------------------------------------------------------------- #pragma once #include "Arduino.h" #include "BaseSensor.h" #define EMON_DEBUG 0 class EmonSensor : public BaseSensor { public: EmonSensor(double voltage, unsigned char bits, double ref, double ratio): BaseSensor() { // Cache _voltage = voltage; _adc_counts = 1 << bits; _pivot = _adc_counts >> 1; // Calculate factor _current_factor = ratio * ref / _adc_counts; // Calculate multiplier calculateMultiplier(); #if EMON_DEBUG Serial.print("[EMON] Current ratio: "); Serial.println(ratio); Serial.print("[EMON] Ref. Voltage: "); Serial.println(ref); Serial.print("[EMON] ADC Counts: "); Serial.println(_adc_counts); Serial.print("[EMON] Current factor: "); Serial.println(_current_factor); Serial.print("[EMON] Multiplier: "); Serial.println(_multiplier); #endif } protected: virtual unsigned int readADC(unsigned char channel) {} void calculateMultiplier() { unsigned int s = 1; unsigned int i = 1; unsigned int m = s * i; while (m * _current_factor < 1) { _multiplier = m; i = (i == 1) ? 2 : (i == 2) ? 5 : 1; if (i == 1) s *= 10; m = s * i; } } double read(unsigned char channel) { int sample; int max = 0; int min = _adc_counts; double filtered; double sum = 0; unsigned long time_span = millis(); for (unsigned long i=0; i<_samples; i++) { // Read analog value sample = readADC(channel); if (sample > max) max = sample; if (sample < min) min = sample; // Digital low pass filter extracts the VDC offset _pivot = (_pivot + (sample - _pivot) / EMON_FILTER_SPEED); filtered = sample - _pivot; // Root-mean-square method sum += (filtered * filtered); } time_span = millis() - time_span; // Quick fix if (_pivot < min || max < _pivot) { _pivot = (max + min) / 2.0; } // Calculate current double rms = _samples > 0 ? sqrt(sum / _samples) : 0; double current = _current_factor * rms; current = (double) (int(current * _multiplier) - 1) / _multiplier; if (current < 0) current = 0; #if EMON_DEBUG Serial.print("[EMON] Total samples: "); Serial.println(_samples); Serial.print("[EMON] Total time (ms): "); Serial.println(time_span); Serial.print("[EMON] Sample frequency (Hz): "); Serial.println(1000 * _samples / time_span); Serial.print("[EMON] Max value: "); Serial.println(max); Serial.print("[EMON] Min value: "); Serial.println(min); Serial.print("[EMON] Midpoint value: "); Serial.println(_pivot); Serial.print("[EMON] RMS value: "); Serial.println(rms); Serial.print("[EMON] Current: "); Serial.println(current); #endif // Check timing if ((time_span > EMON_MAX_TIME) || ((time_span < EMON_MAX_TIME) && (_samples < EMON_MAX_SAMPLES))) { _samples = (_samples * EMON_MAX_TIME) / time_span; } return current; } double _voltage; unsigned long _adc_counts; unsigned int _multiplier = 1; double _current_factor; double _pivot; unsigned long _samples = EMON_MAX_SAMPLES; };