You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
120 lines
3.4 KiB
120 lines
3.4 KiB
// -----------------------------------------------------------------------------
|
|
// NTC Sensor (maps to a NTCSensor)
|
|
// Copyright (C) 2019 by Xose Pérez <xose dot perez at gmail dot com>
|
|
// -----------------------------------------------------------------------------
|
|
|
|
#if SENSOR_SUPPORT && NTC_SUPPORT
|
|
|
|
#pragma once
|
|
|
|
|
|
#include "AnalogSensor.h"
|
|
extern "C" {
|
|
#include "../libs/fs_math.h"
|
|
}
|
|
|
|
class NTCSensor : public AnalogSensor {
|
|
|
|
public:
|
|
|
|
// ---------------------------------------------------------------------
|
|
// Public
|
|
// ---------------------------------------------------------------------
|
|
|
|
NTCSensor() {
|
|
_count = 1;
|
|
_sensor_id = SENSOR_NTC_ID;
|
|
}
|
|
|
|
void setBeta(unsigned long beta) {
|
|
if (beta > 0) _beta = beta;
|
|
}
|
|
|
|
void setUpstreamResistor(unsigned long resistance) {
|
|
_resistance_up = resistance;
|
|
if (_resistance_up > 0) _resistance_down = 0;
|
|
}
|
|
|
|
void setDownstreamResistor(unsigned long resistance) {
|
|
_resistance_down = resistance;
|
|
if (_resistance_down > 0) _resistance_up = 0;
|
|
}
|
|
|
|
void setR0(unsigned long resistance) {
|
|
if (resistance > 0) _R0 = resistance;
|
|
}
|
|
|
|
void setT0(double temperature) {
|
|
if (temperature > 0) _T0 = temperature;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
|
|
// ---------------------------------------------------------------------
|
|
// Sensor API
|
|
// ---------------------------------------------------------------------
|
|
|
|
// Descriptive name of the sensor
|
|
String description() {
|
|
return String("NTC @ TOUT");
|
|
}
|
|
|
|
// Descriptive name of the slot # index
|
|
String description(unsigned char index) {
|
|
return description();
|
|
}
|
|
|
|
// Address of the sensor (it could be the GPIO or I2C address)
|
|
String address(unsigned char index) {
|
|
return String("0");
|
|
}
|
|
|
|
// Type for slot # index
|
|
unsigned char type(unsigned char index) {
|
|
if (index == 0) return MAGNITUDE_TEMPERATURE;
|
|
return MAGNITUDE_NONE;
|
|
}
|
|
|
|
// Current value for slot # index
|
|
double value(unsigned char index) {
|
|
|
|
double temperature = 0;
|
|
|
|
if (index == 0) {
|
|
|
|
// sampled reading
|
|
double read = _read();
|
|
|
|
// Ru = (1023/c - 1) * Rd
|
|
double resistance;
|
|
double alpha = (1023.0 / read) - 1;
|
|
if (_resistance_down > 0) {
|
|
resistance = _resistance_down * alpha;
|
|
} else if (0 == alpha) {
|
|
resistance = _R0;
|
|
} else {
|
|
resistance = _resistance_up / alpha;
|
|
}
|
|
|
|
// 1/T = 1/T0 + 1/B * ln(R/R0)
|
|
temperature = fs_log(resistance / _R0);
|
|
temperature = (1.0 / _T0) + (temperature / _beta);
|
|
temperature = 1.0 / temperature - 273.15;
|
|
|
|
}
|
|
|
|
return temperature;
|
|
|
|
}
|
|
|
|
protected:
|
|
|
|
unsigned long _beta = NTC_BETA;
|
|
unsigned long _resistance_up = NTC_R_UP;
|
|
unsigned long _resistance_down = NTC_R_DOWN;
|
|
unsigned long _R0 = NTC_R0;
|
|
double _T0 = NTC_T0;
|
|
|
|
};
|
|
|
|
#endif // SENSOR_SUPPORT && NTC_SUPPORT
|