python code for serial data to print on window.

Question

I am quite new to python and pyserial. My pc was installed with python 2.7.4 with pyserial and I want to print the serially received data on a seperate window on my pc. First the window has to be opened, then after the serial data should print on that window. Here the window has to be opened once and the serial data has to be continously print on the window until the device stops tramsmitting the data. I tried with this code, but its worthless. please someone help me with the code.

import serial
import Tkinter
from Tkinter import *
s = serial.Serial('COM10',9600)    # open serial port
master = Tk()
master.geometry("1360x750")        # a window pop up with width (1360) and height(750)     which exatly fits my monitor screen..

while 1:
if s.inWaiting():
text = s.readline(s.inWaiting())
frameLabel = Frame( master, padx=40, pady =40)
frameLabel.pack()
w = Text( frameLabel, wrap='word', font="TimesNewRoman 37")
w.insert(12.0,text )
w.pack()
w.configure( bg=master.cget('bg'), relief='flat', state='Normal' )

mainloop()

Answer 1

The problem here is that you have two loops that should be constantly running: The mainloop for the GUI and the loop for transmitting the serial data. What you can do to solve this is to start a new thread to receive the content of the serial port, put it in a Queue, and check periodically in the GUI thread the content of this queue:

import serial
import threading
import time
import Queue
import Tkinter as tk


class SerialThread(threading.Thread):
    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.queue = queue
    def run(self):
        s = serial.Serial('/dev/ttyS0',9600)
        s.write(str.encode('*00T%'))
        time.sleep(0.2)
        while True:
            if s.inWaiting():
                text = s.readline(s.inWaiting())
                self.queue.put(text)

class App(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.geometry("1360x750")
        frameLabel = tk.Frame(self, padx=40, pady =40)
        self.text = tk.Text(frameLabel, wrap='word', font='TimesNewRoman 37',
                            bg=self.cget('bg'), relief='flat')
        frameLabel.pack()
        self.text.pack()
        self.queue = Queue.Queue()
        thread = SerialThread(self.queue)
        thread.start()
        self.process_serial()

    def process_serial(self):
        value=True
        while self.queue.qsize():
            try:
                new=self.queue.get()
                if value:
                 self.text.delete(1.0, 'end')
                value=False
                 self.text.insert('end',new)
            except Queue.Empty:
                pass
        self.after(100, self.process_serial)

app = App()
app.mainloop()

This code is tested with my Pi3 ttyS0 serial port and serially connected PC and slave device: its 100% working with single device connected serially