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====Programming====


**<Face Tracking>**\\

The ''**findface_publisher.py**'' is a publisher that detects people's face and transfer the x,y coordinates of people's face to the face_tracks.py script.\\
Directory: ''**facedetects/nodes/findface_publisher.py**''

<code python | findface_publisher.py> 
#!/usr/bin/env python
import cv2 as cv # opencv library name to cv
import rospy #ros python

from sensor_msgs.msg import Image
from geometry_msgs.msg import Point

rec_point=Point()

rospy.init_node("furo_find")
coordinates_pub = rospy.Publisher("target_coordinate", Point, queue_size=10) #publish x,y coordinate to the node
## Trained XML file for detecting face with its path
face_cascade = cv.CascadeClassifier('/home/dasl/opencv/opencv-4.2.0/data/haarcascades/haarcascade_frontalface_alt.xml')
# Trained XML file for detecting eyes
eye_cascade = cv.CascadeClassifier('/home/dasl/opencv/opencv-4.2.0/data/haarcascades/haarcascade_eye.xml')

# Capture frames from a camera
cap = cv.VideoCapture(0,cv.CAP_V4L)
while True:
	ret, img = cap.read()
	# Convert to gray scale of each frames
	gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)

	# Detects faces of different sizes in the input image
	faces = face_cascade.detectMultiScale(gray, 1.3, 5)

	for (x,y,w,h) in faces:
		# To draw a rectangle in a face
		cv.rectangle(img,(x,y),(x+w,y+h),(255,255,0),2)
		roi_gray = gray[y:y+h, x:x+w]
		roi_color = img[y:y+h, x:x+w]
		target_x=(w/2.0)+x
		target_y=(h/2.0)+y
		
		target_direction_x = target_x/640
		target_direction_y = target_y/480
		
		target_direction_x -= 0.5
		target_direction_y -= 0.5

		target_direction_x *= 2.0
		target_direction_y *= 2.0
		
		rec_point.x = target_direction_x
		rec_point.y = target_direction_y
	
		# Detects eyes of different sizes in the input image
	#	eyes = eye_cascade.detectMultiScale(roi_gray)

		#To draw a rectangle in eyes
		#for (ex,ey,ew,eh) in eyes:
		#	cv.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,127,255),2)

	##Use the below comment if you need to display an image in a window
	screen_res=2560,1440
	window_width=2560
	window_height=1440
	cv.namedWindow('img',cv.WINDOW_NORMAL)
	resized=cv.resize(img,screen_res)
	cv.resizeWindow('img',window_width, window_height)
	flipped =cv.flip(resized,1)
	cv.imshow('img', flipped)
	h,w,c=img.shape
	#print(w)
	#print('width:',img.width)
	#print('height:',img.height)
	

	coordinates_pub.publish(rec_point)
	rospy.loginfo(rec_point)
	rate = rospy.Rate(200)
	#rate.sleep()

	# Wait for Esc key to stop
	if cv.waitKey(5) ==27:
	    break
</code>


The ''**face_tracks.py**'' script is a subscriber that receives the x,y coordinate of a person's face and enable Furo to move toward the person.\\
Directory: ''**head_motor/src/face_tracks.py**''

<code python | face_tracks.py> 
#!/usr/bin/env python
# -*- coding: utf-8 -*-

import rospy
from geometry_msgs.msg import Twist
from std_msgs.msg import Float32
from geometry_msgs.msg import Point

import RPi.GPIO as GPIO
from time import sleep 
GPIO.setmode(GPIO.BOARD)
GPIO.setwarnings(False)
AN2 =33  #pitch 
AN1 = 32  #roll
DIG2 = 18 #pitch
DIG1 = 37 #roll
GPIO.setup(AN2,GPIO.OUT)
GPIO.setup(AN1, GPIO.OUT)
GPIO.setup(DIG2, GPIO.OUT)
GPIO.setup(DIG1, GPIO.OUT)
sleep(1)
p1=GPIO.PWM(AN1,100)
p2=GPIO.PWM(AN2,100)

__author__= "4dimentional@kau.kr"


target_x = 0;
target_y = 0;
error_x = 0;
error_y = 0;
diff_x = 0;
diff_y = 0;
max_output_x = 76.7;
min_output_x = -76.7;
max_output_y = 76.7;
min_output_y = -76.7;


def head_motion_callback(rec_point):
	global target_y,target_x
	global error_x,error_y
	global diff_x,diff_y
	global max_output_x, min_output_x
	global max_output_y, min_output_y

	Px,Dx =20, 30
	Py,Dy = 20 , 30
	
	prev_x = 0
	prev_y = 0
	
	target_x = rec_point.x
	target_y = rec_point.y
	
	error_x = 0 - target_x
	error_y = 0 - target_y
	
	diff_x = prev_x - error_x
	diff_y = prev_y - error_y
	
	prev_x = error_x
	prev_y = error_y
	
	output_x = Px*error_x + Dx*diff_x
	output_y = Py*error_y + Dy*diff_y
	
	if output_x > max_output_x:
		output_x = max_output_x
	elif output_x < min_output_x:
		output_x = min_output_x
	
	if output_x < 0:
		left_speed = abs(output_x)
		GPIO.output(DIG2,GPIO.LOW)
		p2.start(left_speed)
	elif output_x > 0:
		right_speed = abs(output_x)
		GPIO.output(DIG2,GPIO.HIGH)
		p2.start(right_speed)
		
	if output_y > max_output_y:
		output_y = max_output_y
	elif output_y < min_output_y:
		output_y = min_output_y
	
	if output_y < 0:
		upward_speed = abs(output_y)
		GPIO.output(DIG1,GPIO.LOW)
		p1.start(upward_speed)
	elif output_y > 0:
		downward_speed = abs(output_y)
		GPIO.output(DIG1,GPIO.HIGH)
		p1.start(downward_speed)
		
		
	print(output_y)

def head_vel_callback(headCTR):
	head_roll = headCTR.data
	
	if head_roll==4:
		rospy.loginfo("Head downward")		
		GPIO.output(DIG2, GPIO.HIGH)
		p1.start(0)		# set AN2 as HIGH, M2B will turn ON
		p2.start(30)				# set Direction for M2  
						#delay for 2 second

	if head_roll==2:
		rospy.loginfo("Head upward")
		GPIO.output(DIG2, GPIO.LOW)         
		p1.start(0)                       
		p2.start(30)                       
		                          
			    
	if head_roll==5:
		rospy.loginfo("STOP")
		p1.start(0)                          # Direction can ignore
		p2.start(0)                          # Direction can ignore
		                            #delay for 3 second

def listener():
	rospy.init_node("furo_head")		
	rospy.Subscriber("cmd_head",Float32, head_vel_callback)
	rospy.Subscriber("target_coordinate",Point, head_motion_callback)

	rate = rospy.Rate(200)
	while not rospy.is_shutdown():
		rate.sleep()

	
if __name__ == '__main__':
	listener()
</code>


\\
**<Furo's Mobility using Joystick>**

The ''**joy_node**'' script is to convert joystick value to digital value.\\
Directory: ''**joy/src/joy_node.cpp **''

The ''**main.cpp**'' script is a topic that is both a publisher and a subscriber at the same time. It obtains value from the joystick, converts it to float data type and passes it to the motor controller.\\
Directory: ''**learning_joy/src/main.cpp **''\\
CMakeList Directory: ''**learning_joy/CMakeLists.txt **''\\
<code cpp | CMakeLists.txt>
cmake_minimum_required(VERSION 2.8.3)
project(learning_joy)

## Compile as C++11, supported in ROS Kinetic and newer
# add_compile_options(-std=c++11)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  joy
  roscpp
  turtlesim
)

## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)


## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()

###########
## Build ##
###########

## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
# include
  ${catkin_INCLUDE_DIRS}
)


#############
## Testing ##
#############

## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_learning_joy.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()

## Add folders to be run by python nosetests
# catkin_add_nosetests(test)
add_executable(furo src/main.cpp)  #Calls furo instead of main.cpp when launching the script from ROS
target_link_libraries(furo ${catkin_LIBRARIES}) 
</code>
\\
The ''**roboclaw.launch**'' script is to control the motor controller that is connected to the wheels of FURO.\\
Directory: ''**roboclaw_ros/roboclaw_node/launch/roboclaw.launch**''
<code python | roboclaw.launch>
<?xml version="1.0"?>
<launch>

    <arg name="dev" default="/dev/ttyACM0"/>
    <arg name="baud" default="38400"/>
    <arg name="address" default="128"/>
    <arg name="max_speed" default="1"/>
    <arg name="ticks_per_meter" default="265957.447"/>
    <arg name="base_width" default="0.315"/>
    <arg name="run_diag" default="true"/>
    
    #launches furo.py script from roboclaw_node
    <node if="$(arg run_diag)" pkg="roboclaw_node" type="furo.py" name="furo" output="screen">> 
        <param name="~dev" value="$(arg dev)"/>
        <param name="~baud" value="$(arg baud)"/>
        <param name="~address" value="$(arg address)"/>
        <param name="~max_speed" value="$(arg max_speed)"/>
        <param name="~ticks_per_meter" value="$(arg ticks_per_meter)"/>
        <param name="~base_width" value="$(arg base_width)"/>
    </node>

    <node pkg="diagnostic_aggregator" type="aggregator_node"
          name="diagnostic_aggregator">
        <rosparam command="load"
                  file="$(find roboclaw_node)/config/roboclaw_diag.yaml"/>
    </node>

</launch>
</code>
The ''**furo.py**'' from roboclaw_node directory controls the motor controller of Furo's wheels.\\
Directory: ''**roboclaw_ros/roboclaw_node/nodes/furo.py**''
<code python | furo.py>\\
#!/usr/bin/env python
from math import pi, cos, sin

import diagnostic_msgs
import diagnostic_updater
import roboclaw_driver.roboclaw_driver as roboclaw
import rospy
import tf
from geometry_msgs.msg import Quaternion, Twist
from nav_msgs.msg import Odometry

__author__ = "phamquyenanh.qb@gmail.com modifine"


# TODO need to find some better was of handling OSerror 11 or preventing it, any ideas?

class EncoderOdom:
    def __init__(self, ticks_per_meter, base_width):
        self.TICKS_PER_METER = ticks_per_meter
        self.BASE_WIDTH = base_width
        self.odom_pub = rospy.Publisher('/odom', Odometry, queue_size=10)
        self.cur_x = 0
        self.cur_y = 0
        self.cur_theta = 0.0
        self.last_enc_left = 0
        self.last_enc_right = 0
        self.last_enc_time = rospy.Time.now()

    @staticmethod
    def normalize_angle(angle):
        while angle > pi:
            angle -= 2.0 * pi
        while angle < -pi:
            angle += 2.0 * pi
        return angle

    def update(self, enc_left, enc_right):
        left_ticks = enc_left - self.last_enc_left
        right_ticks = enc_right - self.last_enc_right
        self.last_enc_left = enc_left
        self.last_enc_right = enc_right

        dist_left = left_ticks / self.TICKS_PER_METER
        dist_right = right_ticks / self.TICKS_PER_METER
        dist = (dist_right + dist_left) / 2.0

        current_time = rospy.Time.now()
        d_time = (current_time - self.last_enc_time).to_sec()
        self.last_enc_time = current_time

        # TODO find better what to determine going straight, this means slight deviation is accounted
        if left_ticks == right_ticks:
            d_theta = 0.0
            self.cur_x += dist * cos(self.cur_theta)
            self.cur_y += dist * sin(self.cur_theta)
        else:
            d_theta = (dist_right - dist_left) / self.BASE_WIDTH
            r = dist / d_theta
            self.cur_x += r * (sin(d_theta + self.cur_theta) - sin(self.cur_theta))
            self.cur_y -= r * (cos(d_theta + self.cur_theta) - cos(self.cur_theta))
            self.cur_theta = self.normalize_angle(self.cur_theta + d_theta)

        if abs(d_time) < 0.000001:
            vel_x = 0.0
            vel_theta = 0.0
        else:
            vel_x = dist / d_time
            vel_theta = d_theta / d_time

        return vel_x, vel_theta

    def update_publish(self, enc_left, enc_right):
        # 2106 per 0.1 seconds is max speed, error in the 16th bit is 32768
        # TODO lets find a better way to deal with this error
	#print('Left Encoder' , enc_left)
	#print('Right Encoder' , enc_right)
        if abs(enc_left - self.last_enc_left) > 20000:
            rospy.logerr("Ignoring left encoder jump: cur %d, last %d" % (enc_left, self.last_enc_left))
        elif abs(enc_right - self.last_enc_right) > 20000:
            rospy.logerr("Ignoring right encoder jump: cur %d, last %d" % (enc_right, self.last_enc_right))
        else:
            vel_x, vel_theta = self.update(enc_left, enc_right)
            self.publish_odom(self.cur_x, self.cur_y, self.cur_theta, vel_x, vel_theta)

    def publish_odom(self, cur_x, cur_y, cur_theta, vx, vth):
        quat = tf.transformations.quaternion_from_euler(0, 0, cur_theta)
        current_time = rospy.Time.now()

        br = tf.TransformBroadcaster()
        br.sendTransform((cur_x, cur_y, 0),
                         tf.transformations.quaternion_from_euler(0, 0, -cur_theta),
                         current_time,
                         "base_link",
                         "odom")

        odom = Odometry()
        odom.header.stamp = current_time
        odom.header.frame_id = 'odom'

        odom.pose.pose.position.x = cur_x
        odom.pose.pose.position.y = cur_y
        odom.pose.pose.position.z = 0.0
        odom.pose.pose.orientation = Quaternion(*quat)

        odom.pose.covariance[0] = 0.01
        odom.pose.covariance[7] = 0.01
        odom.pose.covariance[14] = 99999
        odom.pose.covariance[21] = 99999
        odom.pose.covariance[28] = 99999
        odom.pose.covariance[35] = 0.01

        odom.child_frame_id = 'base_link'
        odom.twist.twist.linear.x = vx
        odom.twist.twist.linear.y = 0
        odom.twist.twist.angular.z = vth
        odom.twist.covariance = odom.pose.covariance

        self.odom_pub.publish(odom)


class Node:
    def __init__(self):

        self.ERRORS = {0x0000: (diagnostic_msgs.msg.DiagnosticStatus.OK, "Normal"),
                       0x0001: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "M1 over current"),
                       0x0002: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "M2 over current"),
                       0x0004: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Emergency Stop"),
                       0x0008: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Temperature1"),
                       0x0010: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Temperature2"),
                       0x0020: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Main batt voltage high"),
                       0x0040: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Logic batt voltage high"),
                       0x0080: (diagnostic_msgs.msg.DiagnosticStatus.ERROR, "Logic batt voltage low"),
                       0x0100: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "M1 driver fault"),
                       0x0200: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "M2 driver fault"),
                       0x0400: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "Main batt voltage high"),
                       0x0800: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "Main batt voltage low"),
                       0x1000: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "Temperature1"),
                       0x2000: (diagnostic_msgs.msg.DiagnosticStatus.WARN, "Temperature2"),
                       0x4000: (diagnostic_msgs.msg.DiagnosticStatus.OK, "M1 home"),
                       0x8000: (diagnostic_msgs.msg.DiagnosticStatus.OK, "M2 home")}

        rospy.init_node("roboclaw_node")
        rospy.on_shutdown(self.shutdown)
        rospy.loginfo("Connecting to roboclaw")
        dev_name = rospy.get_param("~dev", "/dev/ttyACM1")
        baud_rate = int(rospy.get_param("~baud", "38400"))

        self.address = int(rospy.get_param("~address", "128"))
        if self.address > 0x87 or self.address < 0x80:
            rospy.logfatal("Address out of range")
            rospy.signal_shutdown("Address out of range")

        # TODO need someway to check if address is correct
        try:
            roboclaw.Open(dev_name, baud_rate)
        except Exception as e:
            rospy.logfatal("Could not connect to Roboclaw")
            rospy.logdebug(e)
            rospy.signal_shutdown("Could not connect to Roboclaw")

        self.updater = diagnostic_updater.Updater()
        self.updater.setHardwareID("Roboclaw")
        self.updater.add(diagnostic_updater.
                         FunctionDiagnosticTask("Vitals", self.check_vitals))

        try:
            version = roboclaw.ReadVersion(self.address)
        except Exception as e:
            rospy.logwarn("Problem getting roboclaw version")
            rospy.logdebug(e)
            pass

        if not version[0]:
            rospy.logwarn("Could not get version from roboclaw")
        else:
            rospy.logdebug(repr(version[1]))

        roboclaw.SpeedM1M2(self.address, 0, 0)
        roboclaw.ResetEncoders(self.address)

        self.MAX_SPEED = float(rospy.get_param("~max_speed", "1.0"))
        self.TICKS_PER_METER = float(rospy.get_param("~ticks_per_meter", "265957.447"))
        self.BASE_WIDTH = float(rospy.get_param("~base_width", "0.315"))

        self.encodm = EncoderOdom(self.TICKS_PER_METER, self.BASE_WIDTH)
        self.last_set_speed_time = rospy.get_rostime()

        rospy.Subscriber("cmd_vel", Twist, self.cmd_vel_callback)

        rospy.sleep(1)

        rospy.logdebug("dev %s", dev_name)
        rospy.logdebug("baud %d", baud_rate)
        rospy.logdebug("address %d", self.address)
        rospy.logdebug("max_speed %f", self.MAX_SPEED)
        rospy.logdebug("ticks_per_meter %f", self.TICKS_PER_METER)
        rospy.logdebug("base_width %f", self.BASE_WIDTH)

    def run(self):
        rospy.loginfo("Starting motor drive")
        r_time = rospy.Rate(10)
        while not rospy.is_shutdown():
            # TODO need find solution to the OSError11 looks like sync problem with serial
            status1, enc1, crc1 = None, None, None
            status2, enc2, crc2 = None, None, None
            
            try:
                status1, enc1, crc1 = roboclaw.ReadEncM1(self.address)
            except ValueError:
                pass
            except OSError as e:
                rospy.logwarn("ReadEncM1 OSError: %d", e.errno)
                rospy.logdebug(e)

            try:
                status2, enc2, crc2 = roboclaw.ReadEncM2(self.address)
            except ValueError:
                pass
            except OSError as e:
                rospy.logwarn("ReadEncM2 OSError: %d", e.errno)
                rospy.logdebug(e)

            if (enc1 != None) & (enc2 != None):
                rospy.logdebug(" Encoders %d %d" % (enc1, enc2))
                self.encodm.update_publish(enc1, enc2)
                self.updater.update()
            r_time.sleep()

    def cmd_vel_callback(self, twist):
        self.last_set_speed_time = rospy.get_rostime()

        linear_x = twist.linear.x
        if linear_x==10: 
            roboclaw.ResetEncoders(self.address)
            linear_x=0
        if linear_x > self.MAX_SPEED:
            linear_x = self.MAX_SPEED
        if linear_x < -self.MAX_SPEED:
            linear_x = -self.MAX_SPEED

        vr = linear_x - twist.angular.z * self.BASE_WIDTH / 2.0  # m/s
        vl = linear_x + twist.angular.z * self.BASE_WIDTH / 2.0

        vr_ticks = int(vr * 60)  # ticks/s
        vl_ticks = int(vl * 60)

        rospy.loginfo("vr_ticks:%d vl_ticks: %d", vr_ticks, vl_ticks)

        try:
            # This is a hack way to keep a poorly tuned PID from making noise at speed 0
            if vr_ticks is 0 and vl_ticks is 0:
                roboclaw.ForwardM1(self.address, 0)
                roboclaw.ForwardM2(self.address, 0)
            else:
                if vr_ticks>0:
                    roboclaw.BackwardM1(self.address, vr_ticks)
                else:
                    roboclaw.ForwardM1(self.address, abs(vr_ticks))
                if vl_ticks>0:
                    roboclaw.BackwardM2(self.address, vl_ticks)
                else:
                    roboclaw.ForwardM2(self.address, abs(vl_ticks))
        except OSError as e:
            rospy.logwarn("SpeedM1M2 OSError: %d", e.errno)
            rospy.logdebug(e)

    # TODO: Need to make this work when more than one error is raised
    def check_vitals(self, stat):
        try:
            status = roboclaw.ReadError(self.address)[1]
        except OSError as e:
            rospy.logwarn("Diagnostics OSError: %d", e.errno)
            rospy.logdebug(e)
            return
        state, message = self.ERRORS[status]
        stat.summary(state, message)
        try:
            stat.add("Main Batt V:", float(roboclaw.ReadMainBatteryVoltage(self.address)[1] / 10))
            stat.add("Logic Batt V:", float(roboclaw.ReadLogicBatteryVoltage(self.address)[1] / 10))
            stat.add("Temp1 C:", float(roboclaw.ReadTemp(self.address)[1] / 10))
            stat.add("Temp2 C:", float(roboclaw.ReadTemp2(self.address)[1] / 10))
        except OSError as e:
            rospy.logwarn("Diagnostics OSError: %d", e.errno)
            rospy.logdebug(e)
        return stat

    # TODO: need clean shutdown so motors stop even if new msgs are arriving
    def shutdown(self):
        rospy.loginfo("Shutting down")
        try:
            roboclaw.ForwardM1(self.address, 0)
            roboclaw.ForwardM2(self.address, 0)
        except OSError:
            rospy.logerr("Shutdown did not work trying again")
            try:
                roboclaw.ForwardM1(self.address, 0)
                roboclaw.ForwardM2(self.address, 0)
            except OSError as e:
                rospy.logerr("Could not shutdown motors!!!!")
                rospy.logdebug(e)


if __name__ == "__main__":
    try:
        node = Node()
        node.run()
    except rospy.ROSInterruptException:
        pass
    rospy.loginfo("Exiting")
    
</code>\\
The ''**finalheadmotor.py**'' controls the motor controller of Furo's head.\\
Directory: ''**head_motor/src/finalheadmotor.py **''
<code python | finalheadmotor.py>
#!/usr/bin/env python
# -*- coding: utf-8 -*-

import rospy
from geometry_msgs.msg import Twist
from std_msgs.msg import Float32
import RPi.GPIO as GPIO
from time import sleep 
GPIO.setmode(GPIO.BOARD)
GPIO.setwarnings(False)
AN2 =33
AN1 = 32
DIG2 = 18
DIG1 = 37
GPIO.setup(AN2,GPIO.OUT) #speed of the pitch movement
GPIO.setup(AN1, GPIO.OUT) #speed of the roll movement
GPIO.setup(DIG2, GPIO.OUT) #direction of the pitch movement
GPIO.setup(DIG1, GPIO.OUT) #direction of the roll movement
sleep(1)
p1=GPIO.PWM(AN1,100) #GPIO.PWM(pin,scale)
p2=GPIO.PWM(AN2,100)

__author__= "4dimentional@kau.kr"

class callback:

	def head_vel_callback(self,headCTR):
		head_roll = headCTR.data
		
		if head_roll==1:#1=A(Joystick)
			rospy.loginfo("Head downward")		
			GPIO.output(DIG1, GPIO.HIGH) #downward direction
			p1.start(60)		#speed 60 out of 100
			p2.start(0)				  
							

		elif head_roll==5: #5=LB(Joystick)
			rospy.loginfo("Head upward") 
			GPIO.output(DIG1, GPIO.LOW)  #upward direction       
			p1.start(60)                       
			p2.start(0)
			
		elif head_roll==3: #3=Y(Joystick)
			rospy.loginfo("Head left")
			GPIO.output(DIG2,GPIO.HIGH) #left direction
			p1.start(0)
			p2.start(60)
			
		elif head_roll==2: #2=B(Joystick)
			rospy.loginfo("Head right")
			GPIO.output(DIG2,GPIO.LOW) #right direction
			p1.start(0)
			p2.start(60)                      
			                          
				    
		elif head_roll==4: #LB
			rospy.loginfo("STOP")
			p1.start(0) #speed 0 out of 100           
			p2.start(0)                          
				                        


	def __init__(self):		
		rospy.Subscriber("cmd_head",Float32, self.head_vel_callback)

		rate = rospy.Rate(10)
		while not rospy.is_shutdown():
			rate.sleep()
    
		print(1)

if __name__ == '__main__':
	rospy.init_node('head_roll',anonymous=True)
	try:
		wow = callback()
	except rospy.ROSInitException:
		pass
</code>