Ejemplo n.º 1
0
    def __init__(self):
        rospy.init_node('arduino_servo_node', log_level=rospy.INFO)
        self.dynamic_client = DynamicReconfig.Client("arduino_dynamic_reconfig",timeout=10,config_callback=self.dynamic_callBack)

        # Get the actual node name in case it is set in the launch file
        self.name = rospy.get_name()
        rospy.on_shutdown(self.shutdown)

        # Get all param
        self.getAllParams()

        #subscrib topic to move servo
        rospy.Subscriber(self.moveServoTopic, MoveServo, self.moveServoCB)

        #define publisher to pub arduino firmware version
        self.versionPub = rospy.Publisher(self.firmwareVerTopic, UInt16, queue_size=1)

        #define all services
        self.defineAllServices()

        # Initialize the controlller
        self.controller = Arduino(self.port, self.baud, self.timeout)
        self.controller.connect()
        rospy.loginfo("Connected to Arduino on port:" + self.port + " at " + str(self.baud) + " baud")

        # Enable servo x and servo y
        self.controller.servo_enable(self.servo_x_id, 1)
        self.controller.servo_enable(self.servo_y_id, 1)

        # while loop
        while not rospy.is_shutdown():
            rate = rospy.Rate(self.pubRate)
            firmwareVersion = self.controller.get_firmware_version()
            self.versionPub.publish(firmwareVersion)
            rate.sleep()
Ejemplo n.º 2
0
    def __init__(self):
        rospy.init_node('Arduino', log_level=rospy.DEBUG)

        # Cleanup when terminating the node
        rospy.on_shutdown(self.shutdown)

        # A cmd_vel publisher so we can stop the robot when shutting down
        self.cmd_vel_pub = rospy.Publisher('cmd_vel', Twist, queue_size=10)

        # loop rate
        self.node_rate = int(rospy.get_param("~node_rate", 50))
        r = rospy.Rate(self.node_rate)

        # create instance of the Arduino driver
        self.port = rospy.get_param("~port", "/dev/ttyACM0")
        self.baud = int(rospy.get_param("~baud", 115200))
        self.com_timeout = rospy.get_param("~com_timeout", 0.5)

        rospy.loginfo("Requesting Arduino on port " + self.port + " at " +
                      str(self.baud) + " baud with communication timeout " +
                      str(self.com_timeout) + " s")
        self.controller = Arduino(self.port, self.baud, self.com_timeout)
        self.controller.connect()
        self.controller.reset_odometry()
        rospy.loginfo("Connected to Arduino on port " + self.port + " at " +
                      str(self.baud) + " baud")

        # inform Arduino about IP address
        ip = socket.gethostbyname(socket.gethostname())
        rospy.loginfo("send IP to Arduino: " + ip)
        self.controller.set_ip(ip)

        # Initialize the base controller
        self.base_frame = rospy.get_param("~base_frame", 'base_link')
        self.myBaseController = BaseController(self.controller,
                                               self.base_frame)

        # Reserve a thread lock
        mutex = thread.allocate_lock()

        # Start polling the base controller
        while not rospy.is_shutdown():
            mutex.acquire()
            self.myBaseController.poll()
            mutex.release()

            r.sleep()
Ejemplo n.º 3
0
    def __init__(self):
        rospy.init_node('Arduino', log_level=rospy.DEBUG)
                
        # Cleanup when termniating the node
        rospy.on_shutdown(self.shutdown)
        
        self.port = rospy.get_param("~port", "/dev/ttyACM0")
        self.baud = int(rospy.get_param("~baud", 57600))
        self.timeout = rospy.get_param("~timeout", 0.5)

        # Overall loop rate: should be faster than fastest sensor rate
        self.rate = int(rospy.get_param("~rate", 50))
        r = rospy.Rate(self.rate)

        # Rate at which summary SensorState message is published. Individual sensors publish
        # at their own rates.        
        self.sensorstate_rate = int(rospy.get_param("~sensorstate_rate", 10))
        
        self.use_base_controller = rospy.get_param("~use_base_controller", False)
        
        # Set up the time for publishing the next SensorState message
        now = rospy.Time.now()
        self.t_delta_sensors = rospy.Duration(1.0 / self.sensorstate_rate)
        self.t_next_sensors = now + self.t_delta_sensors
        
        # Initialize a Twist message
        self.cmd_vel = Twist()
  
        # A cmd_vel publisher so we can stop the robot when shutting down
        self.cmd_vel_pub = rospy.Publisher('cmd_vel', Twist)
        
        # The SensorState publisher periodically publishes the values of all sensors on
        # a single topic.
        self.sensorStatePub = rospy.Publisher('~sensor_state', SensorState)
        
        # A service to position a PWM servo
        rospy.Service('~servo_write', ServoWrite, self.ServoWriteHandler)
        
        # A service to read the position of a PWM servo
        rospy.Service('~servo_read', ServoRead, self.ServoReadHandler)
        
        # A service to turn set the direction of a digital pin (0 = input, 1 = output)
        rospy.Service('~digital_set_direction', DigitalSetDirection, self.DigitalSetDirectionHandler)
        
        # A service to turn a digital sensor on or off
        rospy.Service('~digital_write', DigitalWrite, self.DigitalWriteHandler)

        # Initialize the controlller
        self.controller = Arduino(self.port, self.baud, self.timeout, rospy.loginfo)
        
        # Make the connection
        self.controller.connect()
        
        rospy.loginfo("Connected to Arduino on port " + self.port + " at " + str(self.baud) + " baud")
     
        # Reserve a thread lock
        mutex = thread.allocate_lock()

        # Initialize any sensors
        self.mySensors = list()
        
        sensor_params = rospy.get_param("~sensors", dict({}))
        
        for name, params in sensor_params.iteritems():
            # Set the direction to input if not specified
            try:
                params['direction']
            except:
                params['direction'] = 'input'
                
            if params['type'] == "Ping":
                sensor = Ping(self.controller, name, params['pin'], params['rate'])
            elif params['type'] == "GP2D12":
                sensor = GP2D12(self.controller, name, params['pin'], params['rate'])
            elif params['type'] == 'Digital':
                sensor = DigitalSensor(self.controller, name, params['pin'], params['rate'], direction=params['direction'])
            elif params['type'] == 'Analog':
                sensor = AnalogSensor(self.controller, name, params['pin'], params['rate'], direction=params['direction'])
            elif params['type'] == 'PololuMotorCurrent':
                sensor = PololuMotorCurrent(self.controller, name, params['pin'], params['rate'])
            elif params['type'] == 'PhidgetsVoltage':
                sensor = PhidgetsVoltage(self.controller, name, params['pin'], params['rate'])
            elif params['type'] == 'PhidgetsCurrent':
                sensor = PhidgetsCurrent(self.controller, name, params['pin'], params['rate'])
                
#                if params['type'] == "MaxEZ1":
#                    self.sensors[len(self.sensors)]['trigger_pin'] = params['trigger_pin']
#                    self.sensors[len(self.sensors)]['output_pin'] = params['output_pin']

            self.mySensors.append(sensor)
            rospy.loginfo(name + " " + str(params))
              
            self.myBaseController = BaseController(self.controller)
    
        # Start polling the sensors and base controller
        while not rospy.is_shutdown():
            for sensor in self.mySensors:
                mutex.acquire()
                sensor.poll()
                mutex.release()
                    
            if self.use_base_controller:
                mutex.acquire()
                self.myBaseController.poll()
                mutex.release()
            
            # Publish all sensor values on a single topic for convenience
            now = rospy.Time.now()
            
            if now > self.t_next_sensors:
                msg = SensorState()
                msg.header.frame_id = 'base_link'
                msg.header.stamp = now
                for i in range(len(self.mySensors)):
                    msg.name.append(self.mySensors[i].name)
                    msg.value.append(self.mySensors[i].value)
                try:
                    self.sensorStatePub.publish(msg)
                except:
                    pass
                
                self.t_next_sensors = now + self.t_delta_sensors
            
            r.sleep()
Ejemplo n.º 4
0
    def __init__(self):
        rospy.init_node('Arduino', log_level=rospy.DEBUG)

        # Cleanup when termniating the node
        rospy.on_shutdown(self.shutdown)

        self.port = rospy.get_param("~port", "/dev/ttyACM0")
        self.baud = int(rospy.get_param("~baud", 115200))
        self.timeout = rospy.get_param("~timeout", 0.5)
        self.base_frame = rospy.get_param("~base_frame", 'base_link')

        # Overall loop rate: should be faster than fastest sensor rate
        self.rate = int(rospy.get_param("~rate", 50))
        r = rospy.Rate(self.rate)

        # Rate at which summary SensorState message is published. Individual sensors publish
        # at their own rates.
        #self.sensorstate_rate = int(rospy.get_param("~sensorstate_rate", 10))

        self.use_base_controller = rospy.get_param("~use_base_controller",
                                                   False)

        # Set up the time for publishing the next SensorState message
        now = rospy.Time.now()
        #self.t_delta_sensors = rospy.Duration(1.0 / self.sensorstate_rate)
        #self.t_next_sensors = now + self.t_delta_sensors

        # Initialize a Twist message
        self.cmd_vel = Twist()

        # A cmd_vel publisher so we can stop the robot when shutting down
        self.cmd_vel_pub = rospy.Publisher('cmd_vel', Twist)

        # The SensorState publisher periodically publishes the values of all sensors on
        # a single topic.
        #self.sensorStatePub = rospy.Publisher('~sensor_state', SensorState)

        # A service to position a PWM servo
        #rospy.Service('~servo_write', ServoWrite, self.ServoWriteHandler)

        # A service to read the position of a PWM servo
        #rospy.Service('~servo_read', ServoRead, self.ServoReadHandler)

        # A service to turn set the direction of a digital pin (0 = input, 1 = output)
        #rospy.Service('~digital_set_direction', DigitalSetDirection, self.DigitalSetDirectionHandler)

        # A service to turn a digital sensor on or off
        #rospy.Service('~digital_write', DigitalWrite, self.DigitalWriteHandler)

        # A service to set pwm values for the pins
        #rospy.Service('~analog_write', AnalogWrite, self.AnalogWriteHandler)

        # Initialize the controlller
        self.controller = Arduino(self.port, self.baud, self.timeout)

        # Make the connection
        self.controller.connect()

        rospy.loginfo("Connected to Arduino on port " + self.port + " at " +
                      str(self.baud) + " baud")

        # Reserve a thread lock
        mutex = thread.allocate_lock()

        # Initialize any sensors
        #self.mySensors = list()

        #sensor_params = rospy.get_param("~sensors", dict({}))

        #for name, params in sensor_params.iteritems():
        # Set the direction to input if not specified
        #    try:
        #       params['direction']
        #   except:
        #        params['direction'] = 'input'

        #            if params['type'] == "Ping":
        #               sensor = Ping(self.controller, name, params['pin'], params['rate'], self.base_frame)
        #            elif params['type'] == "GP2D12":
        #                sensor = GP2D12(self.controller, name, params['pin'], params['rate'], self.base_frame)
        #            elif params['type'] == 'Digital':
        #                sensor = DigitalSensor(self.controller, name, params['pin'], params['rate'], self.base_frame, direction=params['direction'])
        #            elif params['type'] == 'Analog':
        #                sensor = AnalogSensor(self.controller, name, params['pin'], params['rate'], self.base_frame, direction=params['direction'])
        #            elif params['type'] == 'PololuMotorCurrent':
        #                sensor = PololuMotorCurrent(self.controller, name, params['pin'], params['rate'], self.base_frame)
        #            elif params['type'] == 'PhidgetsVoltage':
        #                sensor = PhidgetsVoltage(self.controller, name, params['pin'], params['rate'], self.base_frame)
        #            elif params['type'] == 'PhidgetsCurrent':
        #               sensor = PhidgetsCurrent(self.controller, name, params['pin'], params['rate'], self.base_frame)

        #                if params['type'] == "MaxEZ1":
        #                    self.sensors[len(self.sensors)]['trigger_pin'] = params['trigger_pin']
        #                    self.sensors[len(self.sensors)]['output_pin'] = params['output_pin']

        #            self.mySensors.append(sensor)
        #            rospy.loginfo(name + " " + str(params))

        # Initialize the base controller if used
        if self.use_base_controller:
            self.myBaseController = BaseController(self.controller,
                                                   self.base_frame)

        # Start polling the sensors and base controller
        while not rospy.is_shutdown():
            #            for sensor in self.mySensors:
            #                mutex.acquire()
            #                sensor.poll()
            #                mutex.release()

            if self.use_base_controller:
                mutex.acquire()
                self.myBaseController.poll()
                mutex.release()

            # Publish all sensor values on a single topic for convenience
            now = rospy.Time.now()

            #            if now > self.t_next_sensors:
            #                msg = SensorState()
            #                msg.header.frame_id = self.base_frame
            #                msg.header.stamp = now
            #                for i in range(len(self.mySensors)):
            #                    msg.name.append(self.mySensors[i].name)
            #                    msg.value.append(self.mySensors[i].value)
            #                try:
            #                    self.sensorStatePub.publish(msg)
            #                except:
            #                    pass

            #                self.t_next_sensors = now + self.t_delta_sensors

            r.sleep()
Ejemplo n.º 5
0
class ArduinoROS():
    def __init__(self):
        rospy.init_node('arduino_servo_node', log_level=rospy.INFO)
        self.dynamic_client = DynamicReconfig.Client("arduino_dynamic_reconfig",timeout=10,config_callback=self.dynamic_callBack)

        # Get the actual node name in case it is set in the launch file
        self.name = rospy.get_name()
        rospy.on_shutdown(self.shutdown)

        # Get all param
        self.getAllParams()

        #subscrib topic to move servo
        rospy.Subscriber(self.moveServoTopic, MoveServo, self.moveServoCB)

        #define publisher to pub arduino firmware version
        self.versionPub = rospy.Publisher(self.firmwareVerTopic, UInt16, queue_size=1)

        #define all services
        self.defineAllServices()

        # Initialize the controlller
        self.controller = Arduino(self.port, self.baud, self.timeout)
        self.controller.connect()
        rospy.loginfo("Connected to Arduino on port:" + self.port + " at " + str(self.baud) + " baud")

        # Enable servo x and servo y
        self.controller.servo_enable(self.servo_x_id, 1)
        self.controller.servo_enable(self.servo_y_id, 1)

        # while loop
        while not rospy.is_shutdown():
            rate = rospy.Rate(self.pubRate)
            firmwareVersion = self.controller.get_firmware_version()
            self.versionPub.publish(firmwareVersion)
            rate.sleep()


    def dynamicReconfig(self, paramList):
        self.pubRate = paramList['firmware_pub_rate']
        self.default_x_deg = paramList['default_x_deg']
        self.default_y_deg = paramList['default_y_deg']
        self.move_delay    = paramList['servo_move_delay']
        #rospy.loginfo("(%f,%d,%d,%d)" %(self.pubRate,self.default_x_deg,self.default_y_deg,self.move_delay))

    def dynamic_callBack(self, config):
        dynamic_param = self.dynamic_client.get_configuration(timeout=3)
        self.dynamicReconfig(dynamic_param)

    def defineAllServices(self):
        # Two services to position/read postion a PWM servo
        rospy.Service('~servo_write', ServoWrite, self.ServoWriteHandler)
        rospy.Service('~servo_read',  ServoRead,  self.ServoReadHandler)

        # Service to enable a servo
        rospy.Service('~servo_enable', ServoEnable, self.ServoEnableHandler)

        # Two services to get all servos position and enabled status
        rospy.Service('~get_all_servos_pos',    GetAllServoPos,    self.GetAllServoPosHandler)
        rospy.Service('~get_all_servos_enable', GetAllServoEnable, self.GetAllServoEnableHandler)

    def moveServoCB(self, msgData):
        self.moveServo(msgData.servoId, msgData.targetPos, msgData.delay)

    def getAllParams(self):
        self.port = rospy.get_param("~port", "/dev/ttyUSB0")
        self.baud = int(rospy.get_param("~baud", 57600))
        self.timeout = rospy.get_param("~timeout", 0.5)
        self.servo_x_id = rospy.get_param("~servo_x_id", 3)
        self.servo_y_id = rospy.get_param("~servo_y_id", 4)
        self.pubRate = rospy.get_param("~version_pub_rate", 0.1)
        self.move_delay = rospy.get_param("~servo_move_delay", 50)
        self.moveServoTopic = rospy.get_param("~move_servo_topic", "/arduino_servo_node/moveServoTopic")
        self.firmwareVerTopic = rospy.get_param("~firmware_version_topic", "/arduino_servo_node/firmwareVersionTopic")
        self.default_x_deg = rospy.get_param("~default_x_deg", 90)
        self.default_y_deg = rospy.get_param("~default_y_deg", 0)

    # Service callback functions
    def ServoWriteHandler(self, req):
        self.controller.servo_write(req.id, req.value, req.delay)
        return ServoWriteResponse()

    def ServoReadHandler(self, req):
        pos = self.controller.servo_read(req.id)
        return ServoReadResponse(pos)

    def ServoEnableHandler(self, req):
        self.controller.servo_enable(req.id, req.flag)
        return ServoEnableResponse()

    def GetAllServoPosHandler(self, req):
        positions = []
        positions = self.controller.getAllServosPos()
        return GetAllServoPosResponse(positions)

    def GetAllServoEnableHandler(self, req):
        enabled = []
        enabled = self.controller.getAllServosEnabled()
        return GetAllServoEnableResponse(enabled)

    def moveServo(self, servo_id, move_angular, move_delay):
        self.controller.servo_write(servo_id, move_angular, move_delay)

    def enableServoByID(self, servo_id, flag):
        self.controller.servo_enable(servo_id, flag)

    def shutdown(self):
        rospy.logwarn("Shutting down arduino_servo_node ...")
        # init servo position to origin
        self.moveServo(self.servo_x_id, self.default_x_deg, self.move_delay)
        self.moveServo(self.servo_y_id, self.default_y_deg, self.move_delay)

        # Close the serial port
        try:
            self.controller.close()
        except:
            pass
        finally:
            rospy.logwarn("Arduino serial port closed.")
            os._exit(0)
Ejemplo n.º 6
0
            (inches). The sensor distance resolution is integer based. Also, the
            maxsonar trigger pin is RX, and the echo pin is PW.
        '''
        return self.execute('z %d %d' % (triggerPin, outputPin))


""" Basic test for connectivity """
if __name__ == "__main__":
    if os.name == "posix":
        portName = "/dev/ttyACM0"
    else:
        portName = "COM43"  # Windows style COM port.

    baudRate = 57600

    myArduino = Arduino(port=portName, baudrate=baudRate, timeout=0.5)
    myArduino.connect()

    print "Sleeping for 1 second..."
    time.sleep(1)

    print "Reading on analog port 0", myArduino.analog_read(0)
    print "Reading on digital port 0", myArduino.digital_read(0)
    print "Blinking the LED 3 times"
    for i in range(3):
        myArduino.digital_write(13, 1)
        time.sleep(1.0)
    #print "Current encoder counts", myArduino.encoders()

    print "Connection test successful.",
Ejemplo n.º 7
0
class ArduinoROS():
    def __init__(self):
        rospy.init_node('arduino', log_level=rospy.INFO)

        # Get the actual node name in case it is set in the launch file
        self.name = rospy.get_name()

        # Cleanup when termniating the node
        rospy.on_shutdown(self.shutdown)

        self.port = rospy.get_param("~port", "/dev/ttyUSB0")
        self.baud = int(rospy.get_param("~baud", 57600))
        self.timeout = rospy.get_param("~timeout", 0.5)
        self.base_frame = rospy.get_param("~base_frame", 'base_link')
        self.motors_reversed = rospy.get_param("~motors_reversed", False)
        # Overall loop rate: should be faster than fastest sensor rate
        self.rate = int(rospy.get_param("~rate", 50))
        r = rospy.Rate(self.rate)

        # Rate at which summary SensorState message is published. Individual sensors publish
        # at their own rates.
        self.sensorstate_rate = int(rospy.get_param("~sensorstate_rate", 10))

        self.use_base_controller = rospy.get_param("~use_base_controller", False)

        # Set up the time for publishing the next SensorState message
        now = rospy.Time.now()
        self.t_delta_sensors = rospy.Duration(1.0 / self.sensorstate_rate)
        self.t_next_sensors = now + self.t_delta_sensors

        # Initialize a Twist message
        self.cmd_vel = Twist()

        # A cmd_vel publisher so we can stop the robot when shutting down
        self.cmd_vel_pub = rospy.Publisher('cmd_vel', Twist, queue_size=5)

        # The SensorState publisher periodically publishes the values of all sensors on
        # a single topic.
        self.sensorStatePub = rospy.Publisher('~sensor_state', SensorState, queue_size=5)##

        # A service to position a PWM servo
        rospy.Service('~servo_write', ServoWrite, self.ServoWriteHandler)##

        # A service to read the position of a PWM servo
        rospy.Service('~servo_read', ServoRead, self.ServoReadHandler)

        # A service to turn set the direction of a digital pin (0 = input, 1 = output)
        rospy.Service('~digital_set_direction', DigitalSetDirection, self.DigitalSetDirectionHandler)

        # A service to turn a digital sensor on or off
        rospy.Service('~digital_write', DigitalWrite, self.DigitalWriteHandler)

        # A service to read the value of a digital sensor
        rospy.Service('~digital_read', DigitalRead, self.DigitalReadHandler)

        # A service to set pwm values for the pins
        rospy.Service('~analog_write', AnalogWrite, self.AnalogWriteHandler)

        # A service to read the value of an analog sensor
        rospy.Service('~analog_read', AnalogRead, self.AnalogReadHandler)

        # Initialize the controlller
        self.controller = Arduino(self.port, self.baud, self.timeout, self.motors_reversed)

        # Make the connection
        self.controller.connect()

        rospy.loginfo("Connected to Arduino on port " + self.port + " at " + str(self.baud) + " baud")

        # Reserve a thread lock
        mutex = thread.allocate_lock()

        # Initialize any sensors
        self.mySensors = list()

        sensor_params = rospy.get_param("~sensors", dict({}))

        for name, params in sensor_params.iteritems():
            # Set the direction to input if not specified
            try:
                params['direction']
            except:
                params['direction'] = 'input'

            if params['type'] == "Ping":
                sensor = Ping(self.controller, name, params['pin'], params['rate'], self.base_frame)
            elif params['type'] == "GP2D12":
                sensor = GP2D12(self.controller, name, params['pin'], params['rate'], self.base_frame)
          #  elif params['type'] == 'Digital':
                #sensor = DigitalSensor(self.controller, name, params['pin'], params['rate'], self.base_frame, direction=params['direction'])
            elif params['type'] == 'Analog':
                sensor = AnalogSensor(self.controller, name, params['pin'], params['rate'], self.base_frame, direction=params['direction'])
            elif params['type'] == 'PololuMotorCurrent':
                sensor = PololuMotorCurrent(self.controller, name, params['pin'], params['rate'], self.base_frame)
            elif params['type'] == 'PhidgetsVoltage':
                sensor = PhidgetsVoltage(self.controller, name, params['pin'], params['rate'], self.base_frame)
            elif params['type'] == 'PhidgetsCurrent':
                sensor = PhidgetsCurrent(self.controller, name, params['pin'], params['rate'], self.base_frame)

#                if params['type'] == "MaxEZ1":
#                    self.sensors[len(self.sensors)]['trigger_pin'] = params['trigger_pin']
#                    self.sensors[len(self.sensors)]['output_pin'] = params['output_pin']
            try:
                self.mySensors.append(sensor)
                rospy.loginfo(name + " " + str(params) + " published on topic " + rospy.get_name() + "/sensor/" + name)
            except:
                rospy.logerr("Sensor type " + str(params['type']) + " not recognized.")

        # Initialize the base controller if used
        if self.use_base_controller:
            self.myBaseController = BaseController(self.controller, self.base_frame, self.name + "_base_controller")

        # Start polling the sensors and base controller
        while not rospy.is_shutdown():
            for sensor in self.mySensors:
                mutex.acquire()
                sensor.poll()
                mutex.release()

            if self.use_base_controller:
                mutex.acquire()
                self.myBaseController.poll()
                mutex.release()

            # Publish all sensor values on a single topic for convenience
            now = rospy.Time.now()

            if now > self.t_next_sensors:
                msg = SensorState()
                msg.header.frame_id = self.base_frame
                msg.header.stamp = now
                for i in range(len(self.mySensors)):
                    msg.name.append(self.mySensors[i].name)
                    msg.value.append(self.mySensors[i].value)
                try:
                    self.sensorStatePub.publish(msg)
                except:
                    pass

                self.t_next_sensors = now + self.t_delta_sensors

            r.sleep()

    # Service callback functions
    def ServoWriteHandler(self, req):
        self.controller.servo_write(req.id, req.value)
        return ServoWriteResponse()

    def ServoReadHandler(self, req):
        pos = self.controller.servo_read(req.id)
        return ServoReadResponse(pos)

    def DigitalSetDirectionHandler(self, req):
        self.controller.pin_mode(req.pin, req.direction)
        return DigitalSetDirectionResponse()

    def DigitalWriteHandler(self, req):
        self.controller.digital_write(req.pin, req.value)
        return DigitalWriteResponse()

    def DigitalReadHandler(self, req):
        value = self.controller.digital_read(req.pin)
        return DigitalReadResponse(value)

    def AnalogWriteHandler(self, req):
        self.controller.analog_write(req.pin, req.value)
        return AnalogWriteResponse()

    def AnalogReadHandler(self, req):
        value = self.controller.analog_read(req.pin)
        return AnalogReadResponse(value)

    def shutdown(self):
        rospy.loginfo("Shutting down Arduino Node...")

        # Stop the robot
        try:
            rospy.loginfo("Stopping the robot...")
            self.cmd_vel_pub.Publish(Twist())
            rospy.sleep(2)
        except:
            pass

        # Close the serial port
        try:
            self.controller.close()
        except:
            pass
        finally:
            rospy.loginfo("Serial port closed.")
            os._exit(0)