/**
   Arduino Calculator

   Copyright (C) 2020, Uri Shaked.
   Released under the MIT License.
*/

#include <LiquidCrystal.h>


/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);
#define BUTTON 5
#define SENSOR 3




void setup() {
  pinMode(BUTTON,INPUT_PULLUP);
  pinMode(SENSOR, INPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  lcd.begin(16, 2);
  lcd.print("HELLO");
  Serial.begin(9600);
}

int sensorstate = 0;
int prevsensorstate = 0;
float time = 0;
float prevtime = 0;
float timediff = 1;

float wheelsize = 100; //10cm
//cm/ms * 36 = km/h
float speed = 0.0;

float distance = 0; //km
int rotations = 0;


float totaltime = 0;




void loop() {
  sensorstate = digitalRead(SENSOR);
  
  
  if(sensorstate == LOW && prevsensorstate != sensorstate){
    lcd.clear();
    prevtime = time;
    time = millis();
    timediff = time - prevtime;
    Serial.println(timediff);

    speed = (wheelsize/timediff)*36; //km/h
    Serial.println(speed); //km/h

    digitalWrite(LED_BUILTIN, HIGH);
    lcd.print(speed);
    lcd.print("km/h");
    

    distance = (wheelsize * rotations)/100;

    lcd.print(" ");
    lcd.print(distance);
    lcd.print("m");
    lcd.setCursor(0,1);

    totaltime = millis()/60000;

    Serial.println(totaltime);

    lcd.print(totaltime);
    lcd.print(" min");
    rotations++;
  }else 
  {
    digitalWrite(LED_BUILTIN, LOW);
  }
  prevsensorstate = sensorstate;

}