Driving the Robot

01_wheel.ipynb
Running the cell code

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import rospy
import json
from std_msgs.msg import String
import time
import math

Import python modules

pub = rospy.Publisher('/robot_command', String, queue_size=1)
rospy.init_node('zetabot', anonymous=True)
time.sleep(1)

Create zetabot Node
Create robot_command Topic Publisher

def move():
    tmp = {"MoveForward": 1}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create a move() function
Convert {“MoveForward”: 1} to Json String
Publish the converted message

def stop():
    tmp = {"Stop": 0}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create stop() function
Convert {“Stop”: 0} to Json String
Publish the converted message

def moveTo():
    tmp = {"MoveDelta": -0.5}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create a moveTo() function
Convert {“MoveDelta”: -0.5} to Json String
Publish the converted message

def moveTo(distance):
    tmp = {"MoveDelta": distance}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create a moveTo(distance) function
Convert {“MoveForward”: distance} to Json string
Publish the converted message

def turnTo():
    tmp = {"TurnDelta": math.radians(45)}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create turnTo() function
Convert 45° to radians
Convert {“TurnDelta”: math.radians(45)} to Json string
Publish the converted message

def turnTo(degree):
    tmp = {"TurnDelta": math.radians(int(degree))}
    msg = json.dumps(tmp)
    rospy.loginfo("Sent: %s", msg)
    pub.publish(msg)

Create turnTo(degree) function
Convert degree(°) to radians
Convert radian to int
Convert {“TurnDelta”: math.radians(int(degree))} to Json string
Publish the converted message

move()
time.sleep(2)
stop()

Run the move() function
2 second time delay
Run the stop() function

moveTo(1)

Execute the moveTo(distance) function
1 distance forward

turnTo(170)
time.sleep(1)
stop()

Run the turnTo(degree) function
170 degree rotation
1 second time delay
Run the stop() function

turnTo(25)
time.sleep(1)
stop()

Run the turnTo(degree) function
25 degree rotation
1 second time delay
Run the stop() function