ensure that there are no duplicate pwms set up for a single GPIO

app.py

@@ -44,7 +44,7 @@ def xml_transfer():
                 shutil.move(str(dir + '/XML/config.xml'),str(dir + '/XML/config_old.xml'))
                 shutil.move('/tmp/aped_device/config.xml',str(dir + '/XML/config.xml'))
                 xml_reader.set_root(str(dir + '/XML/config.xml'))
-                interface_handler = Interface_handler(xml_reader)
+                interface_handler.init_gpio()
             else:
                 SyntaxError('the config.xml has invalid content')
             return {'error': ''}

interface_handler.py

@@ -57,6 +57,9 @@ class Interface_handler:
     def init_gpio(self):
         """initialises the GPIO pins
         """
+        for pwm in self.pwms:
+            if pwm != None:
+                pwm.stop()
         GPIO.setmode(GPIO.BOARD)
         for device_name in self.xml_reader.get_device_names():
             port_info = self.xml_reader.get_port(device_name)