#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>

LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display. ACHTUNG: Adresse kann auch 0x3F sein !!!

// Anschlüsse:
// GND - GND
// VCC - 5V
// SDA - ANALOG Pin 4
// SCL - ANALOG pin 5

const int buttonPin = 8;
int buttonState = 0;

const byte interruptPin = 2;

int pulse = 0;
long time_alt;
int seconds;
int i;

int counts[200];

const int chipSelect = 10;  // used for Arduino


// ===========================
// =======   SETUP   =========
// ===========================

void setup()
   {
    Serial.begin(9600);
    
    pinMode(interruptPin, INPUT);
    
    attachInterrupt(digitalPinToInterrupt(interruptPin), Puls, RISING);
    
    pinMode(buttonPin, INPUT);

    while (!Serial)
       {
       }

    Serial.print("Initializing SD card...");
    // make sure that the default chip select pin is set to
    // output, even if you don't use it:
  
    if (!SD.begin(chipSelect))
       {
        Serial.println("Initialization failed!");
        while (1);
       }

    Serial.println("card initialized.");
    
    lcd.begin();        // initialize the lcd
    lcd.backlight();
    lcd.setCursor(0,0);
    lcd.print("Geigerzaehler");
    lcd.setCursor(0,1);
    lcd.print("Poisson");
    
    delay(3000);
    
    lcd.setCursor(0,0);
    lcd.print("             ");
    lcd.setCursor(0,1);
    lcd.print("            ");

    for(i = 0; i < 1000; i++)
       {
        counts[i] == 0;
       }

    time_alt = millis();
        
   }


// ===========================
// =======    LOOP   =========
// ===========================

void loop()
   {
    while(millis() < time_alt + 60000)
       {
        // waiting for another minute

        seconds = (millis() - time_alt) / 1000;

        lcd.setCursor(0,0);
        lcd.print("             ");
        lcd.setCursor(0,0);
        lcd.print(seconds);
        lcd.print("    ");
        
        lcd.setCursor(0,1);
        lcd.print("            ");
        lcd.setCursor(0,1);
        lcd.print(pulse);
        lcd.print("    ");
        
        delay(200);        
       }
        
    counts[pulse] = counts[pulse] + 1;
        
    buttonState = digitalRead(buttonPin);    

    if(buttonState == LOW)     // counts-data sent to the SD-Card
       {        
        for(i = 0; i < 200; i++)
           {
            String dataString = "";
            
            dataString += String(i);
            dataString += "  ";
            dataString += String(counts[i]);
            
            File dataFile = SD.open("datalog.txt", FILE_WRITE);

            if (dataFile)
               {
                dataFile.println(dataString);
                dataFile.close();
                Serial.println(dataString);
               }
            else
               {
                Serial.println("error opening datalog.txt");
               }            
           }
       }
            
    pulse = 0;
    
    time_alt = time_alt + 60000;
        
   }




// ==============================
// =======   INTERRUPT  =========
// ==============================

void Puls()
   {
    pulse = pulse + 1;
   }