dht22.cpp

/******************************************************************************
  Read Temperature and Humidity
  DHT22 Hardware Connections (Breakoutboard to ESP32):
  
  OUT to GPIO 0
  -  to GND 
  + to 3.3V
  
******************************************************************************/

// *****************************************************
// **
// ** INCLUDES
// **
// *****************************************************
#include <DHT.h>;
#include <math.h>


// *****************************************************
// **
// ** GLOBAL VARIABLES & Defines
// **
// *****************************************************

// -------------------------- DHT22 --------------------------

#define NaN 0.0 / 0.0

#define DHTPIN 0     // what pin we're connected to
#define DHTTYPE DHT22   // DHT 22  (AM2302)
DHT dht(DHTPIN, DHTTYPE); //// Initialize DHT sensor for normal 16mhz Arduino

struct dht22DataStruct
{
  float temperature;
  float humidity;
  float temperature_score;
  float humidity_score;
};

// levels
const float temperature_min_value = -40;
const float temperature_max_value = 80;
int temperature_levels[] = {0,20,22,24,30};
int temperature_levels_percentage[] = {0,70,100,70,0};

const float humidity_min_value = 0;
const float humidity_max_value = 100;
int humidity_levels[] = {0,30,45,55,60,80,100};
int humidity_levels_percentage[] = {0,50,100,100,50,10,0};


void setup()
{
  Serial.begin(115200);
  initDHT22();
}

void loop()
{
  struct dht22DataStruct dht22Data_instance; 
  
  delay(2000);
 
  dht22Data_instance = readDHT22Data();

//  float a= 2.00;
//  float b= 0.07;
//  Serial.println(a/b);
// Serial.println("temp");
//   Serial.println(dht22Data_instance.temperature);
//   Serial.println(dht22Data_instance.temperature_score);
//   Serial.println("-");
//
// Serial.println("hum");
//   Serial.println(dht22Data_instance.humidity);
//   Serial.println(dht22Data_instance.humidity_score);
//   Serial.println("-");
}


// * Calculate The Score Using Some Levels for values and percentages
float calculateScore(uint16_t current_value, int levels_values[],int levels_percentages[], int levels_length)
{
  float output=NAN;
  

  for (int i = 0; i < levels_length; i++) {
    if (current_value <= levels_values[i]) 
    {
      if (i == 0) 
      {
        output = levels_percentages[0];
        break;
      }
      
      float step_value = (float)abs(levels_values[i] - levels_values[i - 1]) / abs(levels_percentages[i] - levels_percentages[i - 1]);
      float percentage_diff = (float)abs(current_value - levels_values[i - 1]) / step_value;

    Serial.println(step_value);   
    Serial.println(2.00/step_value);
    Serial.println(2.00/0.07);
    Serial.println("-");
      // used in case that percentage are not ordered (example for temperature when the 100 is at 22 degrees)
      if(levels_percentages[i - 1] < levels_percentages[i]){
        percentage_diff = -percentage_diff;
      }
      
      output = levels_percentages[i - 1] - percentage_diff;
      break;
    } 
    else 
      {
        if (i == levels_length - 1) 
        {
          output = levels_percentages[levels_length-1];
          break;
        }
      }
   }
  return output;
}



// * Read data from DHT22
struct dht22DataStruct readDHT22Data()
{
  struct dht22DataStruct dht22Data_instance;


  dht22Data_instance.temperature = dht.readTemperature();
  dht22Data_instance.humidity = dht.readHumidity();

  if (isnan(dht22Data_instance.temperature) || isnan(dht22Data_instance.humidity)) {
     dht22Data_instance.temperature_score=NAN;
      dht22Data_instance.humidity_score=NAN;
   
  } 
  else
  {
     dht22Data_instance.temperature_score = calculateScore(dht22Data_instance.temperature,temperature_levels,temperature_levels_percentage,5);
//     dht22Data_instance.humidity_score = calculateScore(dht22Data_instance.humidity,humidity_levels,humidity_levels_percentage,7);
  }
  
 
    
  return dht22Data_instance;
}

void initDHT22()
{
  dht.begin();
}