hi now I’m making a project stopwatch or timer is in control of the android app start, stop and reset the timer in arduino in the show in lcd 16 x 2 but I was wondering how the programming for the method “TIMER STOP” button when finished logic stop on tap then the timer stops and the time is not reset to
00: 00: 00: 00 but stops displaying the time when the accounts at the stop. I really appreciate your help. thanks 
#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>
int h,m,s,ms;
//byte tombol,kode;
LiquidCrystal_I2C lcd(0x3F ,2,1,0,4,5,6,7,3, POSITIVE);
int bluetoothTx = 0;
int bluetoothRx = 1;
char val;
void setup() {
Serial.begin(9600);
lcd.begin(16, 2);
lcd.clear();
lcd.print("JT 777");
lcd.setCursor(0,1);
lcd.print("00:00:00:00");
pinMode(8,INPUT);
pinMode(9,INPUT);
}
void loop() {
if( Serial.available() >0 ) {
val = Serial.read();
Serial.println(val);
}
if(val=='0'){
ms=0;
s=0;
m=0;
h=0;
lcd.setCursor(0,1);
lcd.print(h);
lcd.print(':');
lcd.print(m);
lcd.print(':');
lcd.print(s);
lcd.print(':');
lcd.print(ms);
lcd.print(" ");
delay(250);
}
if(val=='1'){
ms++;
delay(100);
if(ms==10){
ms=0;
s++;
delay(100);
if(s==59){
s=0;
m++;
delay(100);
}
if(m==59){
m=0;
h++;
delay(100);
}
if(h==24){
h=0;
m=0;
s=0;
ms=0;
ms++;
}
}
Serial.println();
lcd.setCursor(0,1);
lcd.print(h);
lcd.print(':');
lcd.print(m);
lcd.print(':');
lcd.print(s);
lcd.print(':');
lcd.print(ms);
lcd.print(" ");
}
}
