#include <LiquidCrystal.h>
#define trg A0
#define ech A1
int dis =0;
int t=0;
int x[2];//distance 
int dx =0 ; //delta dist
int tim[2];//time 
double dt =0;//delta time
int v=0;//spead
int s=0; // step cond
int coun=0;//time 
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
  lcd.begin(16, 2);
  lcd.print("distance: ");
  Serial.begin(9600);
  pinMode(trg, OUTPUT);
  pinMode(ech, INPUT);
}
void loop() {
  digitalWrite(trg, LOW);
  delayMicroseconds(5);
  digitalWrite(trg, HIGH);
  delayMicroseconds(10);
  digitalWrite(trg, LOW);
  t=pulseIn(ech,HIGH);
  dis=t/57;
  dis=(dis*.975)+1;//معامل تصحيح الاشاره
  if (s%2){
    x[0]=dis;
    }else{
      x[1]=dis;
    }
  v=1000*dx/dt;
  //**// warning cause
  if(dis<=10){
    lcd.setCursor(0,1);
    lcd.print("warnning");
  }else{
    lcd.setCursor(0,1);
    lcd.print("        ");
  }/**/
  coun=millis();
  dx=x[0]-x[1];
  dx=abs(dx);// absolut delta of distance 
  //Serial.println(dx); // for checking 

  /**result print **/
  lcd.setCursor(9,0);
  lcd.print(dis);
  lcd.print("  ");
  /****///
  if (s==0){
    s=1;
  }else if (s=1){
    s=0;
  }
  if (s%2){
    tim[0]=coun;
    }else{
      tim[1]=coun;
      }
  dt=tim[0]-tim[1];
  dt=abs(dt)*.001;// absolut delta of time in 
  if (dt!=0){//for not making delta time =0
  v=dx/dt;
  lcd.setCursor(9,1);
  lcd.print("v=");
  lcd.print(v);
  lcd.print("     ");
  }
  delay(200);
  coun=millis();

}