import serial
from tkinter import *
root = Tk()
w, h = root.winfo_screenwidth(), root.winfo_screenheight()
root.geometry("%dx%d+0+0" % (w, h-200))
root.attributes('-fullscreen', True)
varo = StringVar()
varo.set('test1')
c=0
o = Label(root, textvariable=varo,bg="lightblue")
o.pack()
 
o.place(relx=0.5, rely=0.5, anchor="n")
try:
    ser = serial.Serial("/dev/ttyUSB0", 38400)
except: True
while TRUE:
    try:
       cc=str(ser.readline())
    except: True
    c=c+1
    varo.set(c)
    print(c)
    root.update_idletasks()

root.mainLoop()