/////////////////////////////////////////////  
        //    The Vibrating Pressure, Altitude     //
       //      Temperature and Tilt Detector      //
      //       ----------------------------      //
     //             (Arduino Nano)              //           
    //             by Kutluhan Aktar           // 
   //                                         //
  /////////////////////////////////////////////

// Get pressure, temperature and altitude values from a BMP180 sensor with regard to a baseline pressure in mb.
// Detect a tilted plain with the data produced by a tilt sensor digitally as 0 and 1, or LOW and HIGH.
// Also, if this sensor and Arduino Nano are not balanced on a flat plain, get notified by the vibration generated by a vibration motor, and FALSE and OK led.
//
// On a flat plain;
// Tilt sensor is HIGH,
// OK is HIGH,
// FALSE is LOW,
// Vibration motor is LOW,
// Pressure, temperature and altitude values are displayed.
//
// On a tilted plain;
// Tilt sensor is LOW,
// OK is LOW,
// FALSE is HIGH,
// Vibration motor is HIGH,
// Error message is displayed - "Please balance on a flat plain!".
//
// Connections
// Arduino Nano(CH340) :           
//                                BMP180 Pressure Sensor
// A4 --------------------------- SDA
// A5 --------------------------- SCL
//                                LCD Screen (16, 2)
// D7 --------------------------- rs
// D6 --------------------------- en
// D5 --------------------------- d4
// D4 --------------------------- d5
// D3 --------------------------- d6
// D2 --------------------------- d7
//                                Tilt Sensor(Mercury Sensor)
// GND + 10K + D8 --------------- Leg(1)
// 5V --------------------------- Leg(2)
//                                OK Led
// D9 --------------------------- +
//                                FALSE Led
// D10 -------------------------- +
//                                Vibration Motor
// D11 -------------------------- +
// GND -------------------------- -


// Include the LiquidCrystal library.
#include 

// Initialize the library by associating any needed LCD interface pin with the arduino pin number it is connected to.
const int rs = 7, en = 6, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);


// Celcius sign.
byte celcius[8] = {
0b01111,
0b01001,
0b01001,
0b01001,
0b01111,
0b00000,
0b00000,
0b00000
};
// Meter sign.
byte meter[8] = {
0b00000,
0b00000,
0b00000,
0b10001,
0b11011,
0b10101,
0b10001,
0b10001
};

// Your sketch must #include this library, and the Wire library.
// (Wire is a standard library included with Arduino.):

#include 
#include 

// You will need to create an SFE_BMP180 object, here called "pressure":

SFE_BMP180 pressure;

// Connect BMP180 SDA and SCL pins to the labeled pins below.
// Any Arduino pins labeled: SDA  SCL
// Nano, Uno, Pro:            A4   A5
// Mega2560, Due:             20   21
// Leonardo:                   2    3

// Define a baseline pressure (sea-level or other) in mb to predict altitude. 
#define p0 1013

// Define temperature, pressure, and baseline pressure variables.
char status;
double T,P,a;

// Define Tilt Sensor digital pin.
#define tilt 8
// Define OK and FALSE led.
#define OK 9
#define FALSE 10
// Define vibration motor digital pin.
#define vibration 11

void setup() {
// Initialize LCD screen.
lcd.begin(16, 2);
// Create celcius sign.
lcd.createChar(1, celcius);
// Create meter sign.
lcd.createChar(2, meter);

// Initialize the sensor (it is important to get calibration values stored on the device).
pressure.begin();

pinMode(tilt, INPUT);
pinMode(OK, OUTPUT);
pinMode(FALSE, OUTPUT);
pinMode(vibration, OUTPUT);

}

void loop() {
if(digitalRead(tilt) == HIGH){
  lcd.clear();
  // If the system on a flat plain.
  while(digitalRead(tilt) == HIGH){
  digitalWrite(OK, HIGH);
  digitalWrite(FALSE, LOW);
  // Deactivate vibration motor.
  digitalWrite(vibration, LOW);
  // Get data from BMP180 Pressure Sensor.
  get_temperature_and_pressure();

  digitalRead(tilt);
  }
}else if(digitalRead(tilt) == LOW){
  lcd.clear();
  // If tilt sensor is activated.
  while(digitalRead(tilt) == LOW){
  digitalWrite(OK, LOW);
  digitalWrite(FALSE, HIGH);
  // Activate vibration motor.
  digitalWrite(vibration, HIGH);
  // Display error message.
  lcd.setCursor(0,0);
  lcd.print("Please balance");
  lcd.setCursor(0,1);
  lcd.print("on a flat plain!");

  digitalRead(tilt);
  }
}



}

void get_temperature_and_pressure(){
// You must first get a temperature measurement to perform a pressure reading.
  
// Start a temperature measurement:
// If request is successful, the number of ms to wait is returned.
// If request is unsuccessful, 0 is returned.

  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){
      lcd.setCursor(0,0);
      lcd.print(T);
      lcd.write(1);
      lcd.print("C");
      // Start a pressure measurement:
      // The parameter is the oversampling setting, from 0 to 3 (highest res, longest wait).
      // If request is successful, the number of ms to wait is returned.
      // If request is unsuccessful, 0 is returned.
      status = pressure.startPressure(0);
        if (status != 0){
          // Wait for the measurement to complete:
          delay(status);
          // Retrieve the completed pressure measurement:
          // Note that the measurement is stored in the variable P.
          // Note also that the function requires the previous temperature measurement (T).
          // (If temperature is stable, you can do one temperature measurement for a number of pressure measurements.)
          // Function returns 1 if successful, 0 if failure.
          status = pressure.getPressure(P,T);
            if (status != 0){
              lcd.setCursor(3, 1);
              lcd.print(P);
              lcd.print(" mb");
              // Determine your altitude from the pressure reading,
              // use the altitude function along with a baseline pressure (sea-level or other).
              // Parameters: P = absolute pressure in mb, p0 = baseline pressure in mb.
              // Result: a = altitude in m.
              a = pressure.altitude(P,p0);
              lcd.setCursor(9, 0);
              lcd.print(a);
              lcd.print(" ");
              lcd.write(2);
              }
          }
      }
  
   }

   delay(1000);
   
 }