diff --git a/Code/Client/Main.py b/Code/Client/Main.py
index d8e2ec8..f17e6d6 100644
--- a/Code/Client/Main.py
+++ b/Code/Client/Main.py
@@ -488,19 +488,19 @@ class mywindow(QMainWindow,Ui_Client):
     def on_btn_Mode(self,Mode):
         if Mode.text() == "M-Free":
             if Mode.isChecked() == True:
-                self.timer.start(34)
+                #self.timer.start(34)
                 self.TCP.sendData(cmd.CMD_MODE+self.intervalChar+'one'+self.endChar)
         if Mode.text() == "M-Light":
             if Mode.isChecked() == True:
-                self.timer.stop()
+                #self.timer.stop()
                 self.TCP.sendData(cmd.CMD_MODE+self.intervalChar+'two'+self.endChar)
         if Mode.text() == "M-Sonic":
             if Mode.isChecked() == True:
-                self.timer.stop()
+                #self.timer.stop()
                 self.TCP.sendData(cmd.CMD_MODE+self.intervalChar+'three'+self.endChar)    
         if Mode.text() == "M-Line":
             if Mode.isChecked() == True:
-                self.timer.stop()
+                #self.timer.stop()
                 self.TCP.sendData(cmd.CMD_MODE+self.intervalChar+'four'+self.endChar)
          
                                   
diff --git a/Code/Server/Line_Tracking.py b/Code/Server/Line_Tracking.py
index be60497..7ec12b4 100644
--- a/Code/Server/Line_Tracking.py
+++ b/Code/Server/Line_Tracking.py
@@ -1,22 +1,23 @@
 import time
 from Motor import *
 import RPi.GPIO as GPIO
-IR01 = 14
-IR02 = 15
-IR03 = 23
-GPIO.setmode(GPIO.BCM)
-GPIO.setup(IR01,GPIO.IN)
-GPIO.setup(IR02,GPIO.IN)
-GPIO.setup(IR03,GPIO.IN)
 class Line_Tracking:
+    def __init__(self):
+        self.IR01 = 14
+        self.IR02 = 15
+        self.IR03 = 23
+        GPIO.setmode(GPIO.BCM)
+        GPIO.setup(self.IR01,GPIO.IN)
+        GPIO.setup(self.IR02,GPIO.IN)
+        GPIO.setup(self.IR03,GPIO.IN)
     def run(self):
         while True:
             self.LMR=0x00
-            if GPIO.input(IR01)==True:
+            if GPIO.input(self.IR01)==True:
                 self.LMR=(self.LMR | 4)
-            if GPIO.input(IR02)==True:
+            if GPIO.input(self.IR02)==True:
                 self.LMR=(self.LMR | 2)
-            if GPIO.input(IR03)==True:
+            if GPIO.input(self.IR03)==True:
                 self.LMR=(self.LMR | 1)
             if self.LMR==2:
                 PWM.setMotorModel(800,800,800,800)
@@ -29,7 +30,8 @@ class Line_Tracking:
             elif self.LMR==3:
                 PWM.setMotorModel(4000,4000,-2000,-2000)
             elif self.LMR==7:
-                pass
+                #pass
+                PWM.setMotorModel(0,0,0,0)
             
 infrared=Line_Tracking()
 # Main program logic follows:
@@ -37,5 +39,5 @@ if __name__ == '__main__':
     print ('Program is starting ... ')
     try:
         infrared.run()
-    except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
+    except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program  will be  executed.
         PWM.setMotorModel(0,0,0,0)
diff --git a/Code/Server/Ultrasonic.py b/Code/Server/Ultrasonic.py
index 4434267..fd6af8f 100644
--- a/Code/Server/Ultrasonic.py
+++ b/Code/Server/Ultrasonic.py
@@ -3,21 +3,22 @@ from Motor import *
 import RPi.GPIO as GPIO
 from servo import *
 from PCA9685 import PCA9685
-GPIO.setwarnings(False)
-trigger_pin = 27
-echo_pin = 22
-GPIO.setmode(GPIO.BCM)
-GPIO.setup(trigger_pin,GPIO.OUT)
-GPIO.setup(echo_pin,GPIO.IN)
 class Ultrasonic:
+    def __init__(self):
+        GPIO.setwarnings(False)
+        self.trigger_pin = 27
+        self.echo_pin = 22
+        GPIO.setmode(GPIO.BCM)
+        GPIO.setup(self.trigger_pin,GPIO.OUT)
+        GPIO.setup(self.echo_pin,GPIO.IN)
     def send_trigger_pulse(self):
-        GPIO.output(trigger_pin,True)
+        GPIO.output(self.trigger_pin,True)
         time.sleep(0.00015)
-        GPIO.output(trigger_pin,False)
+        GPIO.output(self.trigger_pin,False)
 
     def wait_for_echo(self,value,timeout):
         count = timeout
-        while GPIO.input(echo_pin) != value and count>0:
+        while GPIO.input(self.echo_pin) != value and count>0:
             count = count-1
      
     def get_distance(self):