Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// 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;
#if EMON_REPORT_CURRENT
++_magnitudes;
#endif
#if EMON_REPORT_POWER
++_magnitudes;
#endif
#if EMON_REPORT_ENERGY
++_magnitudes;
#endif
// 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, double &pivot) {
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 char _magnitudes = 0;
unsigned long _adc_counts;
unsigned int _multiplier = 1;
double _current_factor;
unsigned long _samples = EMON_MAX_SAMPLES;
};