sensoresp/include/sensor_sht31.cpp

//Connect SCL to D1, SDA to D2, GND and 3v3
#include "sensor_sht31.h"



Sensor_SHT31::Sensor_SHT31()
{
    sht31 = new Adafruit_SHT31();
}

void Sensor_SHT31::init() //Things to be done during setup()
{    
    Serial.println("initializing sht31");
    if (!sht31->begin(0x44)){
      Serial.println("#ERROR: SHT31 init fail\n");
    }else{
      init_ok=true; //stays false if init failed, sensor will not be read in loop
    }
}

//Also called during setup()
void Sensor_SHT31::setSettings_Temperature(float minchange, unsigned long senddelaymax, unsigned long readdelay)
{
    data_temperature.minchange=minchange;
    data_temperature.senddelaymax=senddelaymax;
    data_temperature.readdelay=readdelay;
}

//Also called during setup()
void Sensor_SHT31::setSettings_Humidity(float minchange, unsigned long senddelaymax, unsigned long readdelay)
{
    data_humidity.minchange=minchange;
    data_humidity.senddelaymax=senddelaymax;
    data_humidity.readdelay=readdelay;
}

//Called during setup
void Sensor_SHT31::advertise(HomieNode& p_sensorNode)
{
    sensorNode = &p_sensorNode;
    sensorNode->advertise("temperature_sht");
    sensorNode->advertise("humidity_sht");
    sensorNode->advertise("sht_heater");
}

void Sensor_SHT31::sensorloop()
{
  if (init_ok) {
    loop_SHT31_temperature();
    loop_SHT31_humidity();
  }
}

void Sensor_SHT31::loop_SHT31_temperature()
{
  sensordata &d=data_temperature;
  bool _changed=false;  

  if (millis() >= (d.lastreadtime+d.readdelay)) {
    d.value = sht31->readTemperature();
    if (fabs(d.lastsentvalue-d.value)>=d.minchange){
      _changed=true;
    }
    d.lastreadtime=millis();
  }

  if (_changed || millis() >= (d.lastsent+d.senddelaymax)) {
    Serial.print("Sending SHT31_temperature. reason=");
    if (_changed) Serial.println("change"); else Serial.println("time");
    

    if (!(isnan(d.value) == 1)){ //success
      sensorNode->setProperty("temperature_sht").send(String(d.value));
      Homie.getLogger() << "temperature_sht " << ": " << d.value << endl;    
      d.lastsentvalue=d.value;
    }

    d.lastsent=millis();
  }
}

void Sensor_SHT31::loop_SHT31_humidity()
{
  sensordata &d=data_humidity;
  bool _changed=false;
  
  if (millis() >= (d.lastreadtime+d.readdelay)) {
    d.value = sht31->readHumidity();
    checkHeater(d.value);
    if (fabs(d.lastsentvalue-d.value)>=d.minchange){
      _changed=true;
    }
    d.lastreadtime=millis();
  }

  if (_changed || millis() >= (d.lastsent+d.senddelaymax)) {
    Serial.print("Sending SHT31_humidity. reason=");
    if (_changed) Serial.println("change"); else Serial.println("time");

    if (!(isnan(d.value) == 1)){ //success
      Homie.getLogger() << "humidity_sht " << ": " << d.value << endl;
      sensorNode->setProperty("humidity_sht").send(String(d.value));
      d.lastsentvalue=d.value;
    }
    d.lastsent=millis();
  }
}

void Sensor_SHT31::checkHeater(float humidity) {
  
  bool heaterstatus=sht31->isHeaterEnabled();
  if (isnan(humidity)==1) { //if sensor cant be read. turn heater on to prevent condensation just in case
    sht31->heater(true);
    Serial.println("checkHeater humidity isnan. turned heater on");
  }else{
    if (!heaterstatus && humidity>=SHT31_HUMIDITY_HEATERON) {//heater was off and humidity is too high
      sht31->heater(true);
      Serial.println("checkHeater humidity too high. turned heater on");
    }else if(heaterstatus && humidity<=SHT31_HUMIDITY_HEATEROFF) { //heater was on and humidity is low enough
      sht31->heater(false);
      Serial.println("checkHeater humidity low enough. turned heater off");
    }
  }
  heaterstatus=sht31->isHeaterEnabled();
  if (heaterstatus!=last_sent_heaterstatus || millis()<30000) { //changed or just booted
    sensorNode->setProperty("sht_heater").send(String(heaterstatus));
    last_sent_heaterstatus=heaterstatus;
  }
  
}