DHT.h

/*
 Copyright (C) AC SOFTWARE SP. Z O.O.
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/
 
#ifndef SRC_SUPLA_SENSOR_DHT_H_
#define SRC_SUPLA_SENSOR_DHT_H_
 
#include <DHT.h>
 
#include "therm_hygro_meter.h"
 
namespace Supla {
namespace Sensor {
class DHT : public ThermHygroMeter {
 public:
  DHT(int pin, int dhtType) : dht(pin, dhtType) {
    dht.begin();
    delay(100);
    retryCountTemp = 0;
    retryCountHumi = 0;
    lastValidTemp = TEMPERATURE_NOT_AVAILABLE;
    lastValidHumi = HUMIDITY_NOT_AVAILABLE;
  }
 
  double getTemp() {
    double value = TEMPERATURE_NOT_AVAILABLE;
    value = dht.readTemperature();
    if (isnan(value)) {
      value = TEMPERATURE_NOT_AVAILABLE;
    }
 
    if (value == TEMPERATURE_NOT_AVAILABLE) {
      retryCountTemp++;
      if (retryCountTemp > 3) {
        retryCountTemp = 0;
      } else {
        value = lastValidTemp;
      }
    } else {
      retryCountTemp = 0;
    }
    lastValidTemp = value;
 
    return value;
  }
 
  double getHumi() {
    double value = HUMIDITY_NOT_AVAILABLE;
    value = dht.readHumidity();
    if (isnan(value)) {
      value = HUMIDITY_NOT_AVAILABLE;
    }
 
    if (value == HUMIDITY_NOT_AVAILABLE) {
      retryCountHumi++;
      if (retryCountHumi > 3) {
        retryCountHumi = 0;
      } else {
        value = lastValidHumi;
      }
    } else {
      retryCountHumi = 0;
    }
    lastValidHumi = value;
 
    return value;
  }
 
 protected:
  ::DHT dht;
  double lastValidTemp;
  double lastValidHumi;
  int8_t retryCountTemp;
  int8_t retryCountHumi;
};
 
};  // namespace Sensor
};  // namespace Supla
 
#endif  // SRC_SUPLA_SENSOR_DHT_H_