/*************************************************************
*                   includes
**************************************************************/
#include <LiquidCrystal_I2C.h>
#include <SD.h>
#include <TimerOne.h>
/*************************************************************
*                   defines
**************************************************************/
#define CS_PIN  10
#define LED_PIN 2
#define DHT22_PIN 9
/*************************************************************
*                   variables globales & structs
**************************************************************/
typedef struct
{
  unsigned char time;
  unsigned char second;
  unsigned char minute;
  unsigned char hour;
  unsigned char day;
  unsigned char month;
  unsigned char year;
}DATETIME_STR;

typedef struct
{
  unsigned int saveData;
  unsigned int readData;
  float humidity;
  float temperature;
}DTH22_STR;

LiquidCrystal_I2C lcd(0x27, 20, 4);
File fil;
DATETIME_STR dateTime;
DTH22_STR dht22;

/*************************************************************
*                           main
**************************************************************/
void setup() {
  LCD_Init();
  SDCard_Init();
  TIMER1_Init();
  RTC_Init();
  GPIO_Init();
  // put your setup code here, to run once:

}

void loop() {
  
  if(dateTime.time)
    dateTime.time = showDateTime();

  // put your main code here, to run repeatedly:

}
/*************************************************************
*                   funciones globales
**************************************************************/
/*funcion que inicia GPIO´s*/
void GPIO_Init(void)
{
  pinMode(LED_PIN, OUTPUT);
}

/*funcion que inicia el lcd*/
void LCD_Init(void)
{
  lcd.init();
  lcd.backlight();
}

/*funcion que inicia la tarjeta de memoria*/
void SDCard_Init(void)
{
  if(!SD.begin(CS_PIN))
  {
    char buffer[20];
    sprintf(buffer,"%s","Error: SD CARD");
    lcdPrint(3,1,buffer); 
    while(1);
  } 
}

/*funcion que inicia el rtc*/
void RTC_Init(void)
{
  dateTime.second = 0;
  dateTime.minute = 0;
  dateTime.hour   = 12;

  dateTime.day    = 28;
  dateTime.month  = 11;
  dateTime.year   = 23;
}

/*funcion que inicia el timer 1*/
void TIMER1_Init(void)
{
  Timer1.initialize(1000000);
  Timer1.attachInterrupt(timerCallback);
  Timer1.start();
}

/*funcion de interrupcion para timer 1*/
void timerCallback(void)
{
  dateTime.time = 1;
  if(++dateTime.second >= 60)
  {
    dateTime.second = 0;
    if(++dateTime.minute >= 60)
    {
      dateTime.minute = 0;
      if(++dateTime.hour >= 24)
      {
        dateTime.hour = 0;
      }
    }
  }
}

/*funcion que controla el pritf del lcd*/
void lcdPrint(int x , int y , String buffer)
{
  lcd.setCursor(x,y);
  lcd.print(buffer);
}

/*funcio que alterna una salida*/
void outputToggle(int pin)
{
  int status = digitalRead(pin);
  digitalWrite(pin,!status);
}

/*funcion que lee el sensor DHT22*/
unsigned int readDHT22(int pin, float* Hum, float* Tem){
  unsigned int status = 0;
  
  pinMode(pin,OUTPUT);
  digitalWrite(pin,LOW);
  delay(2);
  digitalWrite(pin,HIGH);
  delayMicroseconds(30);
  pinMode(pin,INPUT);

  while(digitalRead(pin))
  {
    //add timeout
  }
  while(!digitalRead(pin))
  {
    //add timeout
  }
  while(digitalRead(pin))
  {
    //add timeout
  }

  int i = 32;
  long int HT = 0;
  do{
    while(!digitalRead(pin));
    delayMicroseconds(30);
    if(digitalRead(pin)){
      HT = ((HT<<1) | 1);
    }else{
      HT = (HT<<1);
    }
    while(digitalRead(pin));
    i--;
  }while(i != 0);

  unsigned char cSum = 0;
  i = 8;
  do{
    while(!digitalRead(pin));
    delayMicroseconds(30);
    if(digitalRead(pin)){
      cSum = ((cSum<<1) | 1);
    }else{
      cSum = (cSum<<1);
    }
    while(digitalRead(pin));
    i--;
  }while(i != 0);

  int H = ((0xFFFF0000 & HT)>>16);
  int T = ((0xFFFF & HT));

  unsigned char HH = ((0xFF00 & H)>>8);
  unsigned char HL = (0xFF & H);
  unsigned char TH = ((0xFF00 & T)>>8);
  unsigned char TL = (0xFF & T);

  unsigned char checkSum = (HH+HL+TH+TL);

  if(checkSum && cSum){
    *Hum = H;
    *Hum /= 10;
    *Tem = T;
    *Tem /= 10;
  }else{
    status = 1;
  }
  return status;
}

/*funcion que imprime en la pantalla fecha y hora*/
unsigned int showDateTime(void)
{
  char time[16];
  char date[16];
  char hum[16];
  char temp[16];
  float h , t;

  sprintf(time,"%02d:%02d:%02d",dateTime.hour,dateTime.minute,dateTime.second);
  lcdPrint(0,0,time);
  sprintf(date,"%02d/%02d/%02d",dateTime.day,dateTime.month,dateTime.year);
  lcdPrint(0,1,date);
  
  if(readDHT22(DHT22_PIN,&t,&h) != 0)
  {
    lcdPrint(10,0,"H: ERROR");
    lcdPrint(10,1,"T: ERROR");
  }
  else
  {
    sprintf(hum,"H: %.2d %%",(int)h);
    lcdPrint(10,0,hum);
    sprintf(temp,"T: %d C",(int)t);
    lcdPrint(10,1,temp);
  }
  return 0;
}

/*funcion que escribe en la memoria sd card*/
unsigned int SDCard_Write(char* name,char*data)
{
  unsigned int status = 0; 

  
  return status;
}