// ----------------------------------------------------------------------------- // Abstract Energy Monitor Sensor (other EMON sensors extend this class) // Copyright (C) 2017 by Xose PĂ©rez // ----------------------------------------------------------------------------- #pragma once #include "Arduino.h" #include "BaseSensor.h" class EmonSensor : public BaseSensor { public: // --------------------------------------------------------------------- // Public // --------------------------------------------------------------------- EmonSensor(): BaseSensor() { // Calculate # of magnitudes #if EMON_REPORT_CURRENT ++_magnitudes; #endif #if EMON_REPORT_POWER ++_magnitudes; #endif #if EMON_REPORT_ENERGY ++_magnitudes; #endif } void setVoltage(double voltage) { if (_voltage != voltage) _dirty = true; _voltage = voltage; } void setReference(double reference) { if (_reference != reference) _dirty = true; _reference = reference; } void setCurrentRatio(unsigned char channel, double current_ratio) { if (channel >= _channels) return; if (_current_ratio[channel] != current_ratio) _dirty = true; _current_ratio[channel] = current_ratio; } // --------------------------------------------------------------------- // Sensor API // --------------------------------------------------------------------- void begin() { // Resolution _adc_counts = 1 << _resolution; // Calculations for (unsigned char i=0; i<_channels; i++) { _energy[i] = _current[i] = 0; _pivot[i] = _adc_counts >> 1; _current_factor[i] = _current_ratio[i] * _reference / _adc_counts; _multiplier[i] = calculateMultiplier(_current_factor[i]); } #if SENSOR_DEBUG DEBUG_MSG("[EMON] Reference (mV): %d\n", int(1000 * _reference)); DEBUG_MSG("[EMON] ADC counts: %d\n", _adc_counts); for (unsigned char i=0; i<_channels; i++) { DEBUG_MSG("[EMON] Channel #%d current ratio (mA/V): %d\n", i, int(1000 * _current_ratio[i])); DEBUG_MSG("[EMON] Channel #%d current factor (mA/bit): %d\n", i, int(1000 * _current_factor[i])); DEBUG_MSG("[EMON] Channel #%d Multiplier: %d\n", i, int(_multiplier[i])); } #endif } protected: // --------------------------------------------------------------------- // Protected // --------------------------------------------------------------------- // Initializes internal variables void init() { _current_ratio = new double[_channels]; _current_factor = new double[_channels]; _multiplier = new uint16_t[_channels]; _pivot = new double[_channels]; _current = new double[_channels]; #if EMON_REPORT_ENERGY _energy = new uint32_t[_channels]; #endif } virtual unsigned int readADC(unsigned char channel) {} unsigned int calculateMultiplier(double current_factor) { unsigned int s = 1; unsigned int i = 1; unsigned int m = s * i; unsigned int multiplier; while (m * current_factor < 1) { multiplier = m; i = (i == 1) ? 2 : (i == 2) ? 5 : 1; if (i == 1) s *= 10; m = s * i; } return multiplier; } 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[channel] = (_pivot[channel] + (sample - _pivot[channel]) / EMON_FILTER_SPEED); filtered = sample - _pivot[channel]; // Root-mean-square method sum += (filtered * filtered); } time_span = millis() - time_span; // Quick fix if (_pivot[channel] < min || max < _pivot[channel]) { _pivot[channel] = (max + min) / 2.0; } // Calculate current double rms = _samples > 0 ? sqrt(sum / _samples) : 0; double current = _current_factor[channel] * rms; current = (double) (int(current * _multiplier[channel]) - 1) / _multiplier[channel]; if (current < 0) current = 0; #if SENSOR_DEBUG DEBUG_MSG("[EMON] Channel: %d\n", channel); DEBUG_MSG("[EMON] Total samples: %d\n", _samples); DEBUG_MSG("[EMON] Total time (ms): %d\n", time_span); DEBUG_MSG("[EMON] Sample frequency (Hz): %d\n", int(1000 * _samples / time_span)); DEBUG_MSG("[EMON] Max value: %d\n", max); DEBUG_MSG("[EMON] Min value: %d\n", min); DEBUG_MSG("[EMON] Midpoint value: %d\n", int(_pivot[channel])); DEBUG_MSG("[EMON] RMS value: %d\n", int(rms)); DEBUG_MSG("[EMON] Current (mA): %d\n", int(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; } unsigned char _channels = 0; // Number of ADC channels available unsigned char _magnitudes = 0; // Number of magnitudes per channel unsigned long _samples = EMON_MAX_SAMPLES; // Samples (dynamically modificable) unsigned char _resolution = 10; // ADC resolution in bits unsigned long _adc_counts; // Max count double _voltage = EMON_MAINS_VOLTAGE; // Mains voltage double _reference = EMON_REFERENCE_VOLTAGE; // ADC reference voltage (100%) double * _current_ratio; // Ratio ampers in main loop to voltage in secondary (per channel) double * _current_factor; // Calculated, reads (RMS) to current (per channel) uint16_t * _multiplier; // Calculated, error (per channel) double * _pivot; // Moving average mid point (per channel) double * _current; // Last current reading (per channel) #if EMON_REPORT_ENERGY uint32_t * _energy; // Aggregated energy (per channel) #endif };