import utime

# Initialize variables
start_ticks = None
is_timer_running = False
while True :
    # Function to start the timer
    def start_timer():
        global start_ticks, is_timer_running
        start_ticks = utime.ticks_ms()
        print ("start_ticks",start_ticks)
        is_timer_running = True

    # Function to stop the timer
    def stop_timer():
        global start_ticks, is_timer_running
        start_ticks = None
        is_timer_running = False

    # Function to get the elapsed time in milliseconds
    def get_elapsed_time():
        if start_ticks is not None:
            current_ticks = utime.ticks_ms()
            return utime.ticks_diff(current_ticks, start_ticks)
        else:
            return 0  # Counter is at zero if time measurement is stopped

    # Example usage
    start_timer()  # Start the timer

    # Simulate some work (e.g., a delay of 2 seconds)
    utime.sleep(2)  # Sleep for 2 seconds

    # Get the elapsed time
    elapsed_time = get_elapsed_time()
    print("Elapsed time: {} milliseconds".format(elapsed_time))

    # Stop the timer
    stop_timer()

    # Simulate more work (e.g., another delay of 1 second)
    utime.sleep(1)  # Sleep for 1 second

    # Get the elapsed time after stopping (should be the same as before stopping)
    elapsed_time_after_stop = get_elapsed_time()
    print("Elapsed time after stopping: {} milliseconds".format(elapsed_time_after_stop))