diff --git a/Lasers_und_stuff/main.py b/Lasers_und_stuff/main.py
index bd5adcb..6951fb4 100644
--- a/Lasers_und_stuff/main.py
+++ b/Lasers_und_stuff/main.py
@@ -10,6 +10,8 @@ import random, pygame, sys
 from pygame.locals import *
 from math import fabs
 from math import ceil
+import serial
+
 #import and init pygame
 pygame.init()
 
@@ -82,22 +84,20 @@ def main():
                         screen.communicates.remove("Laser disabled")
                     screen.communicates.append("Laser enabled")
             elif event.type == KEYUP and event.key == K_c:   
-                point1 = [float(x) for x in ask(window, "Point 1 ").split(",")]
-                point2 = [float(x) for x in ask(window, "Point 2 ").split(",")]
-                point3 = [float(x) for x in ask(window, "Point 3 ").split(",")]
+                point1 = get_calibration_point(window, "Point1")
+                point2 = get_calibration_point(window, "Point2")
+                point3 = get_calibration_point(window, "Point3")
                 print point1, point2, point3
                 gunpoint.calibrate(point1, point2, point3)
                 print gunpoint.horizontal_angle, gunpoint.vertical_angle
  
             elif event.type == MOUSEBUTTONUP:
-                print "mouse button up"
                 mouseClicked = True
                 screen.change_color()
-                
+            cannon.send_data()
                 
         
         if mouseClicked :
-            print("Mouse was clicked!") 
             coords = [gunpoint.aim((x/10.0,x/10.0)) for x in range(0,11)]  
             samples = [(x/10.0,x/10.0) for x in range(0, 11)]
             print samples
@@ -145,7 +145,22 @@ def ask(screen, question):
         display_box(screen, question + ": " + "".join(current_string), 20, 400)
     return "".join(current_string)
   
-  
+def get_calibration_point(screen, message):
+    point_string = ask(screen, message)
+    while(not (is_valid_point(point_string)) ):
+        point_string = ask(screen, "Again, " + message)
+    return [float(x) for x in point_string.split(",")]
+    
+def is_valid_point(string):
+    point = string.split(',')  
+    if (len(point) != 2):
+        return False
+    if((not point[0].isdigit()) or (not point[1].isdigit())):
+        return False
+    if(float(point[0]) > 255 or float(point[1]) > 255 or float(point[0])< 0 or float(point[1]) <0 ):
+        return False
+    return True
+
 class Screen:
     
     def __init__(self, window, colors):
@@ -169,7 +184,7 @@ class Screen:
         if cannon.fired:
             self.print_text("Fired!", 20, 150, (150, 20, 40), 40, self.window) 
         
-        self.print_text(cannon.get_data_to_send().__str__(), 20, 300, (0, 0, 0), 30, self.window)               
+        self.print_text([str(x) for x in cannon.get_data()].__str__(), 20, 300, (0, 0, 0), 30, self.window)               
         pygame.display.flip() 
     
     def print_text(self, text,xx,yy,color,text_size, screen):
@@ -195,22 +210,25 @@ class CannonController :
         self.laser = False
         
     def move_left(self, change):
-        self.position[0] -= change  
+        if(self.position[0] >= change):
+            self.position[0] -= change  
+        
     def move_right(self, change):
-        self.position[0] += change
+        if(self.position[0] < 255 - change):
+            self.position[0] += change 
     def move_up(self, change):
-        self.position[1] += change
+        if(self.position[1] < 255 - change):
+            self.position[1] += change
     def move_down(self, change):
-        self.position[1] -= change  
+        if(self.position[1] >= change):
+            self.position[1] -= change
     def check_validity_of_data(self):
         if(fabs(self.position[0]) > 255):
             return False
         if (fabs(self.position[1]) > 255):
             return False
         return True
-    
-    def get_data_to_send(self):
-        # ('a' - os X, 'b' - os Y, 'c' - Strzal, 'd' - laser) 
+    def get_data(self):
         if self.check_validity_of_data():
             data = []
             data.extend(self.position)
@@ -225,9 +243,26 @@ class CannonController :
                 data.append(0)
                 
             return data
+            
         else:
             return [0, 0, 0, 0]
-
+        
+    def get_data_to_send(self):
+        data = self.get_data()
+        return [chr(x) for x in data]
+    
+    def send_data(self):
+        ser = serial.Serial("/dev/ttyACM0", 115200, timeout=1)
+        data = self.get_data_to_send()
+        ser.write('a')
+        ser.write(data[0])
+        ser.write('b')
+        ser.write(data[1])
+        ser.write('c')
+        ser.write(data[2])
+        ser.write('d')
+        ser.write(data[3])
+        
 class Gunpoint :
     def __init__(self, point1, point2, point3):
         self.vertical_angle = point3[1] - point1[1]