DHT_U.cpp

/*!
 *  @file DHT_U.cpp
 *
 *  Temperature & Humidity Unified Sensor Library
 *
 *  This is a library for DHT series of low cost temperature/humidity sensors.
 *
 *  You must have Adafruit Unified Sensor Library library installed to use this
 * class.
 *
 *  Adafruit invests time and resources providing this open source code,
 *  please support Adafruit andopen-source hardware by purchasing products
 *  from Adafruit!
 */
#include "DHT_U.h"

/*!
 *  @brief  Instantiates a new DHT_Unified class
 *  @param  pin
 *          pin number that sensor is connected
 *  @param  type
 *          type of sensor
 *  @param  count
 *          number of sensors
 *  @param  tempSensorId
 *          temperature sensor id
 *  @param  humiditySensorId
 *          humidity sensor id
 */
DHT_Unified::DHT_Unified(uint8_t pin, uint8_t type, uint8_t count, int32_t tempSensorId, int32_t humiditySensorId):
  _dht(pin, type, count),
  _type(type),
  _temp(this, tempSensorId),
  _humidity(this, humiditySensorId)
{}

/*!
 *  @brief  Setup sensor (calls begin on It)
 */
void DHT_Unified::begin() {
  _dht.begin();
}

/*!
 *  @brief  Sets sensor name
 *  @param  sensor
 *          Sensor that will be set
 */
void DHT_Unified::setName(sensor_t* sensor) {
  switch(_type) {
    case DHT11:
      strncpy(sensor->name, "DHT11", sizeof(sensor->name) - 1);
      break;
    case DHT12:
      strncpy(sensor->name, "DHT12", sizeof(sensor->name) - 1);
      break;
    case DHT21:
      strncpy(sensor->name, "DHT21", sizeof(sensor->name) - 1);
      break;
    case DHT22:
      strncpy(sensor->name, "DHT22", sizeof(sensor->name) - 1);
      break;
    default:
      // TODO: Perhaps this should be an error?  However main DHT library doesn't enforce
      // restrictions on the sensor type value.  Pick a generic name for now.
      strncpy(sensor->name, "DHT?", sizeof(sensor->name) - 1);
      break;
  }
  sensor->name[sizeof(sensor->name)- 1] = 0;
}

/*!
 *  @brief  Sets Minimum Delay Value
 *  @param  sensor
 *          Sensor that will be set
 */
void DHT_Unified::setMinDelay(sensor_t* sensor) {
  switch(_type) {
    case DHT11:
      sensor->min_delay = 1000000L;  // 1 second (in microseconds)
      break;
    case DHT12:
      sensor->min_delay = 2000000L;  // 2 second (in microseconds)
      break;
    case DHT21:
      sensor->min_delay = 2000000L;  // 2 seconds (in microseconds)
      break;
    case DHT22:
      sensor->min_delay = 2000000L;  // 2 seconds (in microseconds)
      break;
    default:
      // Default to slowest sample rate in case of unknown type.
      sensor->min_delay = 2000000L;  // 2 seconds (in microseconds)
      break;
  }
}

/*!
 *  @brief  Instantiates a new DHT_Unified Temperature Class
 *  @param  parent
 *          Parent Sensor
 *  @param  id
 *          Sensor id
 */
DHT_Unified::Temperature::Temperature(DHT_Unified* parent, int32_t id):
  _parent(parent),
  _id(id)
{}

/*!
 *  @brief  Reads the sensor and returns the data as a sensors_event_t
 *  @param  event
 *  @return always returns true
 */
bool DHT_Unified::Temperature::getEvent(sensors_event_t* event) {
  // Clear event definition.
  memset(event, 0, sizeof(sensors_event_t));
  // Populate sensor reading values.
  event->version     = sizeof(sensors_event_t);
  event->sensor_id   = _id;
  event->type        = SENSOR_TYPE_AMBIENT_TEMPERATURE;
  event->timestamp   = millis();
  event->temperature = _parent->_dht.readTemperature();
  
  return true;
}

/*!
 *  @brief  Provides the sensor_t data for this sensor
 *  @param  sensor
 */
void DHT_Unified::Temperature::getSensor(sensor_t* sensor) {
  // Clear sensor definition.
  memset(sensor, 0, sizeof(sensor_t));
  // Set sensor name.
  _parent->setName(sensor);
  // Set version and ID
  sensor->version         = DHT_SENSOR_VERSION;
  sensor->sensor_id       = _id;
  // Set type and characteristics.
  sensor->type            = SENSOR_TYPE_AMBIENT_TEMPERATURE;
  _parent->setMinDelay(sensor);
  switch (_parent->_type) {
    case DHT11:
      sensor->max_value   = 50.0F;
      sensor->min_value   = 0.0F;
      sensor->resolution  = 2.0F;
      break;
    case DHT12:
      sensor->max_value   = 60.0F;
      sensor->min_value   = -20.0F;
      sensor->resolution  = 0.5F;
      break;
    case DHT21:
      sensor->max_value   = 80.0F;
      sensor->min_value   = -40.0F;
      sensor->resolution  = 0.1F;
      break;
    case DHT22:
      sensor->max_value   = 125.0F;
      sensor->min_value   = -40.0F;
      sensor->resolution  = 0.1F;
      break;
    default:
      // Unknown type, default to 0.
      sensor->max_value   = 0.0F;
      sensor->min_value   = 0.0F;
      sensor->resolution  = 0.0F;
      break;
  }
}

/*!
 *  @brief  Instantiates a new DHT_Unified Humidity Class
 *  @param  parent
 *          Parent Sensor
 *  @param  id
 *          Sensor id
 */
DHT_Unified::Humidity::Humidity(DHT_Unified* parent, int32_t id):
  _parent(parent),
  _id(id)
{}

/*!
 *  @brief  Reads the sensor and returns the data as a sensors_event_t
 *  @param  event
 *  @return always returns true
 */
bool DHT_Unified::Humidity::getEvent(sensors_event_t* event) {
  // Clear event definition.
  memset(event, 0, sizeof(sensors_event_t));
  // Populate sensor reading values.
  event->version           = sizeof(sensors_event_t);
  event->sensor_id         = _id;
  event->type              = SENSOR_TYPE_RELATIVE_HUMIDITY;
  event->timestamp         = millis();
  event->relative_humidity = _parent->_dht.readHumidity();
  
  return true;
}

/*!
 *  @brief  Provides the sensor_t data for this sensor
 *  @param  sensor
 */
void DHT_Unified::Humidity::getSensor(sensor_t* sensor) {
  // Clear sensor definition.
  memset(sensor, 0, sizeof(sensor_t));
  // Set sensor name.
  _parent->setName(sensor);
  // Set version and ID
  sensor->version         = DHT_SENSOR_VERSION;
  sensor->sensor_id       = _id;
  // Set type and characteristics.
  sensor->type            = SENSOR_TYPE_RELATIVE_HUMIDITY;
  _parent->setMinDelay(sensor);
  switch (_parent->_type) {
    case DHT11:
      sensor->max_value   = 80.0F;
      sensor->min_value   = 20.0F;
      sensor->resolution  = 5.0F;
      break;
    case DHT12:
      sensor->max_value   = 95.0F;
      sensor->min_value   = 20.0F;
      sensor->resolution  = 5.0F;
      break;
    case DHT21:
      sensor->max_value   = 100.0F;
      sensor->min_value   = 0.0F;
      sensor->resolution  = 0.1F;
      break;
    case DHT22:
      sensor->max_value   = 100.0F;
      sensor->min_value   = 0.0F;
      sensor->resolution  = 0.1F;
      break;
    default:
      // Unknown type, default to 0.
      sensor->max_value   = 0.0F;
      sensor->min_value   = 0.0F;
      sensor->resolution  = 0.0F;
      break;
  }
}