from tkinter import *
import serial, os, pty
import pickle



def draw_point(x,y):

	green = "#476042"
	canvas.create_oval(x-5,y-5, x+5, y+5, fill=green)

def sendToSerial():
	#x, y = event.x, event.y
	x = root.winfo_pointerx() - root.winfo_rootx()
	y = root.winfo_pointery() - root.winfo_rooty()

	posn = str(x) + ", " + str(y)
	b = posn.encode('utf-8')
	ser.write(b)

	readSerial()

def readSerial():
	b = os.read(master, 100)
	posn = b.decode("utf-8") 
	coords = posn.replace('"', "").split(",")
	x,y = coords
	
	draw_point(int(x),int(y))

	root.after(100, sendToSerial)


if __name__ == '__main__':
	master, slave = pty.openpty()
	s_name = os.ttyname(slave)
	ser = serial.Serial(s_name)

	root = Tk()
	root.title("Path")

	canvas = Canvas(root, width=400, height=400)
	canvas.pack()

	root.after(1000,sendToSerial)
	root.mainloop()