Weather Station

#include <Wire.h> //for I2C communication

#include <Adafruit_GFX.h> // include library for the OLED

#include <Adafruit_SSD1306.h> // include library for the OLED

#include <SFE_BMP180.h> // include library for the pressure sensor

#include <DHT.h> //include library for the temperature and humidity sensor

#define DHTPIN 2     // pin that DTH11 is connected

#define DHTTYPE DHT11   // DHT 11

#define OLED_RESET 4    //OLED

#define DS3231_I2C_ADDRESS 0x68

Adafruit_SSD1306 display(OLED_RESET);

#define ALTITUDE 100 // set with your altitude

SFE_BMP180 pressure;

DHT dht(DHTPIN, DHTTYPE);

byte decToBcd(byte val){

  return( (val/10*16) + (val%10) );

}

byte bcdToDec(byte val){

  return( (val/16*10) + (val%16) );

}

void setup(){

  if (pressure.begin())

    Serial.println("BMP180 init success");

  else {

    while(1); // Pause forever.

  }

  Wire.begin();  // initialize wire communication

  dht.begin();  //initialize  dht sensor 

  Serial.begin(9600); // initialize  serial monitor

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C); //initialize display

  // set the initial time here:

  // DS3231 seconds, minutes, hours, day, date, month, year

  // uncomment the following line after setting up the time once

  //setDS3231time(33,54,13,1,15,12,19);

}

void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte dayOfMonth, byte month, byte year){

  //set the time and date data to DS3231

  Wire.beginTransmission(DS3231_I2C_ADDRESS);

  Wire.write(0); // set next input to start at the seconds register

  Wire.write(decToBcd(second)); // set seconds

  Wire.write(decToBcd(minute)); // set minutes

  Wire.write(decToBcd(hour)); // set hours

  Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday)

  Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31)

  Wire.write(decToBcd(month)); // set month

  Wire.write(decToBcd(year)); // set year (0 to 99)

  Wire.endTransmission();

}

void readDS3231time(byte *second, byte *minute, byte *hour, byte *dayOfWeek, byte *dayOfMonth, byte *month, byte *year){

  Wire.beginTransmission(DS3231_I2C_ADDRESS);

  Wire.write(0); // set DS3231 register pointer to 00h

  Wire.endTransmission();

  Wire.requestFrom(DS3231_I2C_ADDRESS, 7);

  // request seven bytes of data from DS3231 starting from register 00h

  *second = bcdToDec(Wire.read() & 0x7f);

  *minute = bcdToDec(Wire.read());

  *hour = bcdToDec(Wire.read() & 0x3f);

  *dayOfWeek = bcdToDec(Wire.read());

  *dayOfMonth = bcdToDec(Wire.read());

  *month = bcdToDec(Wire.read());

  *year = bcdToDec(Wire.read());

}

// Displays data and time on the OLED display

void displayTime(){ 

  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;

  // retrieve data from DS3231

  readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);

  display.clearDisplay(); //clearing the display

  display.setTextColor(WHITE); //setting the color to white

  display.setTextSize(1); //setting the color size

  display.setCursor(0,0); //set the cursor coordinates

  // dispaying the day of the week

  switch(dayOfWeek){ 

    case 1:

      display.print("Sunday");

      break;

    case 2:

      display.print("Monday");

      break;

    case 3:

      display.print("Tuesday");

      break;

    case 4:

      display.print("Wednesday");

      break;

    case 5:

      display.print("Thursday");

      break;

    case 6:

      display.print("Friday");

      break;

    case 7:

     display.print("Saturday");

      break;

  }

  display.setCursor(0,20); // setting the cursor coordinates

  display.print(hour, DEC); //display the hour

  // convert the byte variable to a decimal number when displayed

  display.print(":");

  if (minute<10){

    display.print("0");

  }

  display.print(minute, DEC);

  display.print(":");

  if (second<10){

    display.print("0");

  }

  display.print(second, DEC);

  display.setCursor(0,10);

  display.print(dayOfMonth, DEC);

  display.print("/");

  display.print(month, DEC);

  display.print("/");

  display.print(year, DEC);

}

// Displays the temperature and humidity

void displayTempHumid(){

  delay(2000);

  // Reading temperature or humidity takes about 250 milliseconds!

  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)

  float h = dht.readHumidity();

  // Read temperature as Celsius

  float t = dht.readTemperature();

  // Read temperature as Fahrenheit

  float f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).

  if (isnan(h) || isnan(t) || isnan(f)) {

   display.clearDisplay();

   display.setTextColor(WHITE);

   display.setTextSize(1);

   display.setCursor(5,0);

   display.print("Failed to read from DHT sensor!");

   return;

  }

  display.clearDisplay();

  display.setTextColor(WHITE);

  display.setTextSize(1);

  display.setCursor(0,0);

  display.print("Humidity: "); 

  display.print(h);

  display.print(" %\t");

  display.print("Temp: "); 

  display.print(t);

  display.print(" C"); 

  display.print("Temp: "); 

  display.print(t*1.8+32);

  display.print(" F"); */

}

void displayPressure(){ 

  char status;

  double T,P,a;

  status = pressure.startTemperature();

  if (status != 0){

    // Wait for the measurement to complete:

    delay(status);

    // Retrieve the completed temperature measurement:

    // Note that the measurement is stored in the variable T.

    // Function returns 1 if successful, 0 if failure.

    status = pressure.getTemperature(T);

    if (status != 0){

      if (status != 0){

        // Wait for the measurement to complete:

        delay(status);

        if (status != 0){

          // Print out the measurement:

          display.setTextColor(WHITE);

          display.setTextSize(1);

          display.setCursor(0,20);

          display.print("Pressure: ");

          display.print(P,2);

          display.print(" mb ");

        }

        else Serial.println("error retrieving pressure measurement\n"); //for debugging

      }

    }

    else Serial.println("error retrieving temperature measurement\n"); //for debugging

  }

  else Serial.println("error starting temperature measurement\n"); //for debugging

}

void loop(){

  displayTempHumid();

  displayPressure();

  display.display();

  delay(3000);

  displayTime(); 

  display.display();

  delay(3000);

}