Humidity and Temperature Monitoring Using Arduino

// Connections:
// LCD pin 1 to Arduino GND
// LCD pin 2 to Arduino 5v
// LCD pin 3 (Contrast) to GND
// rs (LCD pin 4) to Arduino pin 12
// rw (LCD pin 5) to Arduino pin 11
// enable (LCD pin 6) to Arduino pin 10
// LCD pin 15 to Arduino pin 13
// LCD pin 16 to Arduino GND
// LCD pins d4, d5, d6, d7 to Arduino pins 5, 4, 3, 2

//Tested with SHT21 Breakout from Misenso
//SHT21 pin SDA to Arduino Analog pin 4
//SHT21 pin SCL to Arduino Analog pin 5
//SHT21 pin GND to Arduino GND
//SHT21 pin VCC to Arduino 3v (not 5v)

//RGB LED
//Red Cathode to Arduino pin 9
//Blue Cathode to Arduino pin 8
//Green Cathode to Arduino pin 7
//Anode to 270 ohm resistor to 5V

#include <LiquidCrystal.h>
#include <Wire.h>
#include <LibHumidity.h>

LibHumidity humidity = LibHumidity(0);

LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

int backLight = 13;    // pin 13 will control the backlight
int RedLEDPin = 9;                // LED connected to digital pin 9
int BlueLEDPin = 8;                // LED connected to digital pin 8
int GreenLEDPin = 7;                // LED connected to digital pin 7


void setup()
{
  pinMode(backLight, OUTPUT);
  digitalWrite(backLight, HIGH); // turn backlight on. Replace 'HIGH' with 'LOW' to turn it off.

 //I2C
  pinMode(16, OUTPUT);
  digitalWrite(16, LOW);  //GND pin
  pinMode(17, OUTPUT);
  digitalWrite(17, HIGH); //VCC pin

 //Furnace / AC Indicator
  pinMode(RedLEDPin, OUTPUT);      // sets the digital pin as output
  pinMode(BlueLEDPin, OUTPUT);      // sets the digital pin as output
  pinMode(GreenLEDPin, OUTPUT);      // sets the digital pin as output

}

void loop()
{
  lcd.begin(20,4);              // columns, rows.  use 16,2 for a 16x2 LCD, etc.
  lcd.clear();                  // start with a blank screen
  lcd.setCursor(0,0);           // set cursor to column 0, row 0 (the first row)
  lcd.print("Humidity: ");    // change this text to whatever you like. keep it clean.
  lcd.print(humidity.GetHumidity());
  lcd.setCursor(0,1);           // set cursor to column 0, row 1
  lcd.print("Temp in C: ");
  lcd.print(humidity.GetTemperatureC());
  lcd.setCursor(0,2);         // set cursor to column 0, row 2
  lcd.print("Temp in F: ");
  lcd.print(humidity.GetTemperatureF());
 {
if (humidity.GetTemperatureF() < 60)
{
  digitalWrite(RedLEDPin, LOW);  // sets the Red LED on
  digitalWrite(BlueLEDPin, HIGH);  // sets the Blue LED off
  digitalWrite(GreenLEDPin, LOW);  // sets the Green LED off

}
else if (humidity.GetTemperatureF() >= 75)
{
  digitalWrite(BlueLEDPin, LOW);   // sets the Blue LED on
  digitalWrite(RedLEDPin, HIGH);  // sets the Red LED off
  digitalWrite(GreenLEDPin, HIGH);  // sets the Green LED off
}
else
{
  digitalWrite(GreenLEDPin, LOW);  // sets the Green LED on
  digitalWrite(BlueLEDPin, HIGH);  // sets the Blue LED off
  digitalWrite(RedLEDPin, HIGH);  // sets the Red LED off
 
}
 }
 
  delay (20000);
}