/***************************************************************************
    This is a library for the BME280 humidity, temperature & pressure sensor
  
    Designed specifically to work with the Adafruit BME280 Breakout
    ----> http://www.adafruit.com/products/2650
  
    These sensors use I2C or SPI to communicate, 2 or 4 pins are required
    to interface. The device's I2C address is either 0x76 or 0x77.
  
    Adafruit invests time and resources providing this open source code,
    please support Adafruit andopen-source hardware by purchasing products
    from Adafruit!
  
    Written by Limor Fried & Kevin Townsend for Adafruit Industries.
    BSD license, all text above must be included in any redistribution
   ***************************************************************************/
  

  byte requestBytes[3];   // for incoming xBee data

  byte answerBytes[3];
  
  
  #include <Wire.h>
  #include <SPI.h>
  #include <Adafruit_Sensor.h>
  #include <Adafruit_BME280.h>

  #include <SoftwareSerial.h>

  
  #define BME_SCK 13
  #define BME_MISO 12
  #define BME_MOSI 11
  #define BME_CS 10
  
  //Adafruit_BME280 bme; // I2C
  //Adafruit_BME280 bme(BME_CS); // hardware SPI
  Adafruit_BME280 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
  

  //on crée la liaison xBee
  
  SoftwareSerial xBee(2, 3);
  
  
  int luxPin = A0;
  float rawRange = 1024;
  float logRange = 5.0; 

  
  void setup() {

      xBee.begin(9600);
      analogReference(EXTERNAL);
      char requestBytes[3];
      //tableau d'octets contenant les données
      byte answerBytes[4];

      bme.begin();
  }
  
  
  void loop() { 
  
  

      if (xBee.available() <= 3 && xBee.available() >= 1 ) {
        xBee.readBytes(requestBytes,3);

        if(requestBytes[0] == 'G' && requestBytes[1] == 'E' && requestBytes[2] == 'T') //Si 3 octets correspondant à G,E et T sont envoyé on envoie les données météo
        {
          //on charge les donnée dans la chaîne de bytes d'envoi (modélisé par un tableau)

          answerBytes[0] = pressureToByte(bme.readPressure());
          answerBytes[1] = tempToByte(bme.readTemperature());
          answerBytes[2] = humidityToByte(bme.readHumidity());

          answerBytes[3] = luxToByte(getLux());
  

          //On envoie le buffer constituée des 4 donnée
          xBee.write(answerBytes,4);
  
          //on vide le buffer série pour éviter un décalage des requêtes
          while(xBee.available() > 0)
              xBee.read();

        }
      }
     // printValues();
  }
  

  int arrondiSuperieur(float val)
  {
    int newVal = 0;
    //arrondi supérieur
    if(val-(int)val >= 0.5)
      newVal = (int)val+1;
    else
      newVal = (int)val;
  
    return newVal;
  }
  

  //Ces fonctions convertissent chaque donnée en un seul octet
  
  byte pressureToByte(float pressure)

  {

    return (byte)(arrondiSuperieur(pressure/100.0)-845);

  }
  
  byte tempToByte(float temp)
  {
    return (byte)arrondiSuperieur(temp);
  }
  
  byte humidityToByte(float humidity)
  {
    return (byte)arrondiSuperieur(humidity);
  }
  

  byte luxToByte(float lux)
  {
    return (byte)(lux*255/10000);
  }
  
  //https://cdn-learn.adafruit.com/downloads/pdf/adafruit-ga1a12s202-log-scale-analog-light-sensor.pdf
  float getLux()
  {
    int raw = analogRead(luxPin); 
    float logLux = raw * logRange / rawRange;
    float res = pow(10, logLux);
    if(res > 10000.0)
    {
      res = 10000.0;
    }
    return res;
  }