import serial
import threading
import time
from tkinter import *
root=Tk()
root.title('Usart-stm32')
root.geometry('250x250')
root['bg']='blue'
v = StringVar()
tex=Text(root,width=20,height=2,
         font='Verdana 12',
         wrap=WORD)
def get1(event,*args,**kwargs):
    threading.Timer(1.0, get1).start()
    time.sleep(2.0)
    print ("hello")
but3=Button(root,text='Hello')
but3.bind('<Button-1>',get1)
ent1 = Entry (root, textvariable = v,bg="black",fg="white",font=20,width=20,bd=20)
ent1.pack()
tex.pack()
but3.pack()
root.mainloop()

 Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Users\111\AppData\Local\Programs\Python\Python35-32\lib\threading.py", line 914, in _bootstrap_inner
    self.run()
  File "C:\Users\111\AppData\Local\Programs\Python\Python35-32\lib\threading.py", line 1180, in run
    self.function(*self.args, **self.kwargs)
TypeError: get1() missing 1 required positional argument: 'event'
hello

 import tkinter as tk
import time
def tick():
    label.after(200, tick)
    label['text'] = time.strftime('%H:%M:%S')
root=tk.Tk()
label = tk.Label(font='sans 20')
label.pack()
label.after_idle(tick)
root.mainloop()

  s = ser.read(10)        # read up to ten bytes (timeout)