#include <Every.h>
//#include <LCD_I2C.h>
#include <Adafruit_SSD1306.h>
#include <Wire.h>
#include <Adafruit_GFX.h>

//LCD_I2C lcd(0x27);  // set adress for LCD
#define SSD1306_128_64 // display name
#define OLED_ADDR 0x3C // I2C display adress
// reset pin not used on 4-pin OLED module
Adafruit_SSD1306 display(-1);  // -1 = no reset pin

// declaration of variables
bool ButtonState = HIGH;
bool ButtonState_K1 = HIGH;
float ElapsedTime = 0.0;
unsigned long ButtonPressedLastTime = 0;
unsigned long ButtonPressedTime = 0;


// declaration of constants
//static Every t1(200);  // every 200 msec
const byte ButtonPin = 2;

void setup() {
  // put your setup code here, to run once:
//lcd.begin();
//lcd.backlight();
//lcd.print("ElapsedTime [ms]:");

pinMode(ButtonPin, INPUT_PULLUP); // init digital pin as input (Button)
pinMode(4, OUTPUT);

// initialize and clear display
  display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR); // turn display on and set adress
  display.clearDisplay();
  display.display();

    // display a line of text
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(27,30);
  display.print("Starting");
}

void loop() {
  // put your main code here, to run repeatedly:
// read button and signalize buttonstate 
  ButtonState = digitalRead(ButtonPin);
  if(ButtonState){
    digitalWrite(4,HIGH);
  }
  else{digitalWrite(4,LOW);}
  
  // edge detection and time measurement
  if (ButtonState_K1==LOW && ButtonState ==HIGH){
    ButtonPressedTime = millis();
    ElapsedTime = ButtonPressedTime - ButtonPressedLastTime;
    /*lcd.setCursor(0,1);
    lcd.print(ElapsedTime);
    lcd.setCursor(8,0);
    lcd.print(ButtonPressedTime);
    lcd.setCursor(0,0);
    lcd.print(ButtonPressedLastTime);
    //Serial.println(millis());*/
  }

  // hold variables
  ButtonState_K1 = ButtonState;
  ButtonPressedLastTime = ButtonPressedTime;
}