HamsterPython

Python setup

• Note you are on the HamsterNet

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$ export ROS_IP=<your IP>

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$ export ROS_MASTER_URI=http://10.0.2.<HAMSTER AGENT Number>:11311

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Python Example 1

• Receive laser scan from robot to decide if free

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1. !/usr/bin/env python

import rospy from sensor_msgs.msg import LaserScan

def is_free(ranges ,start_index, end_index ,min_distance): #sub array from angle to angle s_ranges = ranges[start_index:end_index] #filter the array b_ranges = filter(lambda x: x <= min_distance, s_ranges) if len(b_ranges) > 1 : print "BLOCKED" else : print "FREE"

def callback(msg): is_free(msg.ranges,160,200,0.2)

rospy.init_node('scan_values')

1. Put your Hamster number instead of agent<number>
2. The agent number is printed on the Hamster cover

sub = rospy.Subscriber('/agent14/scan', LaserScan, callback)

rospy.spin()

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