/*
  An open-source desk weather station for Arduino with weather forecast
  Source :   https://www.sla99.fr
  Source prevision meteo : https://forum.mysensors.org/topic/3718/bmp280-i2c/6
  Date : 2018-02-18
*/
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

#define BME_SCK 13
#define BME_MISO 12
#define BME_MOSI 11
#define BME_CS 10

#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME280 bme; // I2C

double P; // for pressure conversion
int altitude = 600;
int valm = 0;
int valh = 0;
unsigned long time = 0;
double timeToStart = 0;


//prévision meteo
const char *weather[] = { "stable", "soleil", "nuage", "instab", "tempete", "indef" };
enum FORECAST
{
  STABLE = 0,     // "Stable Weather Pattern"
  SUNNY = 1,      // "Slowly rising Good Weather", "Clear/Sunny "
  CLOUDY = 2,     // "Slowly falling L-Pressure ", "Cloudy/Rain "
  UNSTABLE = 3,   // "Quickly rising H-Press",     "Not Stable"
  THUNDERSTORM = 4, // "Quickly falling L-Press",    "Thunderstorm"
  UNKNOWN = 5     // "Unknown (More Time needed)
};
// for forecast
float lastPressure = -1;
float lastTemp = -1;
int lastForecast = -1;
const int LAST_SAMPLES_COUNT = 5;
float lastPressureSamples[LAST_SAMPLES_COUNT];
// this CONVERSION_FACTOR is used to convert from Pa to kPa in forecast algorithm
// get kPa/h be dividing hPa by 10
#define CONVERSION_FACTOR (1.0/10.0)
int minuteCount = 0;
bool firstRound = true;
// average value is used in forecast algorithm.
float pressureAvg;
// average after 2 hours is used as reference value for the next iteration.
float pressureAvg2;
float dP_dt;



#define PIN_SCE   7
#define PIN_RESET 6
#define PIN_DC    5
#define PIN_SDIN  4
#define PIN_SCLK  3

#define LCD_C     LOW
#define LCD_D     HIGH

#define LCD_X     84
#define LCD_Y     48

static const byte ASCII[][5] =
{
  {0x00, 0x00, 0x00, 0x00, 0x00} // 20
  , {0x00, 0x00, 0x5f, 0x00, 0x00} // 21 !
  , {0x00, 0x07, 0x00, 0x07, 0x00} // 22 "
  , {0x14, 0x7f, 0x14, 0x7f, 0x14} // 23 #
  , {0x24, 0x2a, 0x7f, 0x2a, 0x12} // 24 $
  , {0x23, 0x13, 0x08, 0x64, 0x62} // 25 %
  , {0x36, 0x49, 0x55, 0x22, 0x50} // 26 &
  , {0x00, 0x05, 0x03, 0x00, 0x00} // 27 '
  , {0x00, 0x1c, 0x22, 0x41, 0x00} // 28 (
  , {0x00, 0x41, 0x22, 0x1c, 0x00} // 29 )
  , {0x14, 0x08, 0x3e, 0x08, 0x14} // 2a *
  , {0x08, 0x08, 0x3e, 0x08, 0x08} // 2b +
  , {0x00, 0x50, 0x30, 0x00, 0x00} // 2c ,
  , {0x08, 0x08, 0x08, 0x08, 0x08} // 2d -
  , {0x00, 0x60, 0x60, 0x00, 0x00} // 2e .
  , {0x20, 0x10, 0x08, 0x04, 0x02} // 2f /
  , {0x3e, 0x51, 0x49, 0x45, 0x3e} // 30 0
  , {0x00, 0x42, 0x7f, 0x40, 0x00} // 31 1
  , {0x42, 0x61, 0x51, 0x49, 0x46} // 32 2
  , {0x21, 0x41, 0x45, 0x4b, 0x31} // 33 3
  , {0x18, 0x14, 0x12, 0x7f, 0x10} // 34 4
  , {0x27, 0x45, 0x45, 0x45, 0x39} // 35 5
  , {0x3c, 0x4a, 0x49, 0x49, 0x30} // 36 6
  , {0x01, 0x71, 0x09, 0x05, 0x03} // 37 7
  , {0x36, 0x49, 0x49, 0x49, 0x36} // 38 8
  , {0x06, 0x49, 0x49, 0x29, 0x1e} // 39 9
  , {0x00, 0x36, 0x36, 0x00, 0x00} // 3a :
  , {0x00, 0x56, 0x36, 0x00, 0x00} // 3b ;
  , {0x08, 0x14, 0x22, 0x41, 0x00} // 3c <
  , {0x14, 0x14, 0x14, 0x14, 0x14} // 3d =
  , {0x00, 0x41, 0x22, 0x14, 0x08} // 3e >
  , {0x02, 0x01, 0x51, 0x09, 0x06} // 3f ?
  , {0x32, 0x49, 0x79, 0x41, 0x3e} // 40 @
  , {0x7e, 0x11, 0x11, 0x11, 0x7e} // 41 A
  , {0x7f, 0x49, 0x49, 0x49, 0x36} // 42 B
  , {0x3e, 0x41, 0x41, 0x41, 0x22} // 43 C
  , {0x7f, 0x41, 0x41, 0x22, 0x1c} // 44 D
  , {0x7f, 0x49, 0x49, 0x49, 0x41} // 45 E
  , {0x7f, 0x09, 0x09, 0x09, 0x01} // 46 F
  , {0x3e, 0x41, 0x49, 0x49, 0x7a} // 47 G
  , {0x7f, 0x08, 0x08, 0x08, 0x7f} // 48 H
  , {0x00, 0x41, 0x7f, 0x41, 0x00} // 49 I
  , {0x20, 0x40, 0x41, 0x3f, 0x01} // 4a J
  , {0x7f, 0x08, 0x14, 0x22, 0x41} // 4b K
  , {0x7f, 0x40, 0x40, 0x40, 0x40} // 4c L
  , {0x7f, 0x02, 0x0c, 0x02, 0x7f} // 4d M
  , {0x7f, 0x04, 0x08, 0x10, 0x7f} // 4e N
  , {0x3e, 0x41, 0x41, 0x41, 0x3e} // 4f O
  , {0x7f, 0x09, 0x09, 0x09, 0x06} // 50 P
  , {0x3e, 0x41, 0x51, 0x21, 0x5e} // 51 Q
  , {0x7f, 0x09, 0x19, 0x29, 0x46} // 52 R
  , {0x46, 0x49, 0x49, 0x49, 0x31} // 53 S
  , {0x01, 0x01, 0x7f, 0x01, 0x01} // 54 T
  , {0x3f, 0x40, 0x40, 0x40, 0x3f} // 55 U
  , {0x1f, 0x20, 0x40, 0x20, 0x1f} // 56 V
  , {0x3f, 0x40, 0x38, 0x40, 0x3f} // 57 W
  , {0x63, 0x14, 0x08, 0x14, 0x63} // 58 X
  , {0x07, 0x08, 0x70, 0x08, 0x07} // 59 Y
  , {0x61, 0x51, 0x49, 0x45, 0x43} // 5a Z
  , {0x00, 0x7f, 0x41, 0x41, 0x00} // 5b [
  , {0x02, 0x04, 0x08, 0x10, 0x20} // 5c ¥
  , {0x00, 0x41, 0x41, 0x7f, 0x00} // 5d ]
  , {0x04, 0x02, 0x01, 0x02, 0x04} // 5e ^
  , {0x40, 0x40, 0x40, 0x40, 0x40} // 5f _
  , {0x00, 0x01, 0x02, 0x04, 0x00} // 60 `
  , {0x20, 0x54, 0x54, 0x54, 0x78} // 61 a
  , {0x7f, 0x48, 0x44, 0x44, 0x38} // 62 b
  , {0x38, 0x44, 0x44, 0x44, 0x20} // 63 c
  , {0x38, 0x44, 0x44, 0x48, 0x7f} // 64 d
  , {0x38, 0x54, 0x54, 0x54, 0x18} // 65 e
  , {0x08, 0x7e, 0x09, 0x01, 0x02} // 66 f
  , {0x0c, 0x52, 0x52, 0x52, 0x3e} // 67 g
  , {0x7f, 0x08, 0x04, 0x04, 0x78} // 68 h
  , {0x00, 0x44, 0x7d, 0x40, 0x00} // 69 i
  , {0x20, 0x40, 0x44, 0x3d, 0x00} // 6a j
  , {0x7f, 0x10, 0x28, 0x44, 0x00} // 6b k
  , {0x00, 0x41, 0x7f, 0x40, 0x00} // 6c l
  , {0x7c, 0x04, 0x18, 0x04, 0x78} // 6d m
  , {0x7c, 0x08, 0x04, 0x04, 0x78} // 6e n
  , {0x38, 0x44, 0x44, 0x44, 0x38} // 6f o
  , {0x7c, 0x14, 0x14, 0x14, 0x08} // 70 p
  , {0x08, 0x14, 0x14, 0x18, 0x7c} // 71 q
  , {0x7c, 0x08, 0x04, 0x04, 0x08} // 72 r
  , {0x48, 0x54, 0x54, 0x54, 0x20} // 73 s
  , {0x04, 0x3f, 0x44, 0x40, 0x20} // 74 t
  , {0x3c, 0x40, 0x40, 0x20, 0x7c} // 75 u
  , {0x1c, 0x20, 0x40, 0x20, 0x1c} // 76 v
  , {0x3c, 0x40, 0x30, 0x40, 0x3c} // 77 w
  , {0x44, 0x28, 0x10, 0x28, 0x44} // 78 x
  , {0x0c, 0x50, 0x50, 0x50, 0x3c} // 79 y
  , {0x44, 0x64, 0x54, 0x4c, 0x44} // 7a z
  , {0x00, 0x08, 0x36, 0x41, 0x00} // 7b {
  , {0x00, 0x00, 0x7f, 0x00, 0x00} // 7c |
  , {0x00, 0x41, 0x36, 0x08, 0x00} // 7d }
  , {0x10, 0x08, 0x08, 0x10, 0x08} // 7e ←
  , {0x78, 0x46, 0x41, 0x46, 0x78} // 7f →
};

void LcdCharacter(char character)
{
  LcdWrite(LCD_D, 0x00);
  for (int index = 0; index < 5; index++)
  {
    LcdWrite(LCD_D, ASCII[character - 0x20][index]);
  }
  LcdWrite(LCD_D, 0x00);
}

void LcdClear(void)
{
  for (int index = 0; index < LCD_X * LCD_Y / 8; index++)
  {
    LcdWrite(LCD_D, 0x00);
  }
}

void LcdInitialise(void)
{
  pinMode(PIN_SCE, OUTPUT);
  pinMode(PIN_RESET, OUTPUT);
  pinMode(PIN_DC, OUTPUT);
  pinMode(PIN_SDIN, OUTPUT);
  pinMode(PIN_SCLK, OUTPUT);
  digitalWrite(PIN_RESET, LOW);
  digitalWrite(PIN_RESET, HIGH);
  LcdWrite(LCD_C, 0x21 );  // LCD Extended Commands.
  LcdWrite(LCD_C, 0xB8 );  // Set LCD Vop (Contrast).
  LcdWrite(LCD_C, 0x04 );  // Set Temp coefficent. //0x04
  LcdWrite(LCD_C, 0x14 );  // LCD bias mode 1:48. //0x13
  LcdWrite(LCD_C, 0x20 );  // LCD Basic Commands
  LcdWrite(LCD_C, 0x0C );  // LCD in normal mode.
}

void LcdString(char *characters)
{
  while (*characters)
  {
    LcdCharacter(*characters++);
  }
}

void LcdWrite(byte dc, byte data)
{
  digitalWrite(PIN_DC, dc);
  digitalWrite(PIN_SCE, LOW);
  shiftOut(PIN_SDIN, PIN_SCLK, MSBFIRST, data);
  digitalWrite(PIN_SCE, HIGH);
}

void setup(void)
{
  Serial.begin(9600);
  bool status;
  status = bme.begin();
  //initialisation boutons
  pinMode(14, INPUT);
  pinMode(15, INPUT);
  digitalWrite(14, HIGH);
  digitalWrite(15, HIGH);

}

void loop(void)
{
  time = millis();
  //phase d'initialisation pour paramétrage altitude
  if (time < 60000) {
    valm = digitalRead(14);    
    if (valm == LOW) {
      altitude = altitude - 10;
      delay(100);
    }

    valh = digitalRead(15); 
    if (valh == LOW) {
      altitude = altitude + 10;
      delay(100);
    }
    LcdInitialise();
    LcdClear();
    printValuesStart();
    delay(100);
  }
  //phase normale
  else {
    LcdInitialise();
    LcdClear();
    printValues();
    delay(60000);
  }
}

void printValues() {

  char tempBuffer[5];
  LcdString("Temp:");
  dtostrf(bme.readTemperature(), 4, 1, tempBuffer);
  LcdString(tempBuffer);
  LcdString(" C ");

  P = getP((bme.readPressure() / 100.0F), bme.readTemperature());
  char PresBuffer[5];
  LcdString("Pres:");
  dtostrf(P, 4, 0, PresBuffer);
  LcdString(PresBuffer);
  LcdString("hPa");

  char humBuffer[5];
  LcdString("Humi:");
  dtostrf(bme.readHumidity(), 2, 0, humBuffer);
  LcdString(humBuffer);
  LcdString("%    ");

  char altiBuffer[4];
  LcdString("Alti:");
  dtostrf(altitude, 4, 0,  altiBuffer);
  LcdString(altiBuffer);
  LcdString("m  ");

  int forecast = sample(P);
  LcdString("Prev:");
  LcdString(weather[forecast]);
  
}

void printValuesStart() {
  char altiBuffer[4];
  LcdString("Alti:");
  dtostrf(altitude, 4, 0,  altiBuffer);
  LcdString(altiBuffer);
  LcdString("m  ");

  char compteur[2];
  LcdString("Reste :");
  timeToStart = 60 - time / 1000;
  dtostrf(timeToStart, 2, 0,  compteur);
  LcdString(compteur);
  LcdString(" s");
}

//fonction qui corrige la pression en fonction de l'altitude
double getP(double Pact, double temp) {
  return Pact * pow((1 - ((0.0065 * altitude) / (temp + 0.0065 * altitude + 273.15))), -5.257);
}

float getLastPressureSamplesAverage()
{
  float lastPressureSamplesAverage = 0;
  for (int i = 0; i < LAST_SAMPLES_COUNT; i++)
  {
    lastPressureSamplesAverage += lastPressureSamples[i];
  }
  lastPressureSamplesAverage /= LAST_SAMPLES_COUNT;

  return lastPressureSamplesAverage;
}

// Algorithm found here
// http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
// Pressure in hPa -->  forecast done by calculating kPa/h
int sample(float pressure)
{
  // Calculate the average of the last n minutes.
  int index = minuteCount % LAST_SAMPLES_COUNT;
  lastPressureSamples[index] = pressure;

  minuteCount++;
  if (minuteCount > 185)
  {
    minuteCount = 6;
  }

  if (minuteCount == 5)
  {
    pressureAvg = getLastPressureSamplesAverage();
  }
  else if (minuteCount == 35)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change * 2; // note this is for t = 0.5hour
    }
    else
    {
      dP_dt = change / 1.5; // divide by 1.5 as this is the difference in time from 0 value.
    }
  }
  else if (minuteCount == 65)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) //first time initial 3 hour
    {
      dP_dt = change; //note this is for t = 1 hour
    }
    else
    {
      dP_dt = change / 2; //divide by 2 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 95)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 1.5; // note this is for t = 1.5 hour
    }
    else
    {
      dP_dt = change / 2.5; // divide by 2.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 125)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    pressureAvg2 = lastPressureAvg; // store for later use.
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2; // note this is for t = 2 hour
    }
    else
    {
      dP_dt = change / 3; // divide by 3 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 155)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2.5; // note this is for t = 2.5 hour
    }
    else
    {
      dP_dt = change / 3.5; // divide by 3.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 185)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 3; // note this is for t = 3 hour
    }
    else
    {
      dP_dt = change / 4; // divide by 4 as this is the difference in time from 0 value
    }
    pressureAvg = pressureAvg2; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
    firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
  }

  int forecast = UNKNOWN;
  if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
  {
    forecast = UNKNOWN;
  }
  else if (dP_dt < (-0.25))
  {
    forecast = THUNDERSTORM;
  }
  else if (dP_dt > 0.25)
  {
    forecast = UNSTABLE;
  }
  else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
  {
    forecast = CLOUDY;
  }
  else if ((dP_dt > 0.05) && (dP_dt < 0.25))
  {
    forecast = SUNNY;
  }
  else if ((dP_dt > (-0.05)) && (dP_dt < 0.05))
  {
    forecast = STABLE;
  }
  else
  {
    forecast = UNKNOWN;
  }

  // uncomment when debugging
  //Serial.print(F("Forecast at minute "));
  //Serial.print(minuteCount);
  //Serial.print(F(" dP/dt = "));
  //Serial.print(dP_dt);
  //Serial.print(F("kPa/h --> "));
  //Serial.println(weather[forecast]);

  return forecast;
}