Difference between revisions of "HamsterPython"

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{{DISPLAYTITLE:Hamster Python API}}
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[[Category:Hamster]]
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=== Python setup ===
 
=== Python setup ===
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* Note you are on the HamsterNet
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* Note you are connected to the hamster_net (wifi / router)
  
 
<syntaxhighlight lang="bash" line='line'>
 
<syntaxhighlight lang="bash" line='line'>
Line 10: Line 13:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
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* If the Hamster is powered and your terminal is well configured you should be able to
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See all data streams
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<syntaxhighlight lang="bash" line='line'>
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$ rostopic list
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</syntaxhighlight>
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See imagery from the robot
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<syntaxhighlight lang="bash" line='line'>
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$ rqt_image_view
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</syntaxhighlight>
  
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=== Python Example 1 ===
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* Install dependencies
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* Receive laser scan from robot to decide if free
 
  
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<syntaxhighlight lang="python" line='line'>
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<syntaxhighlight lang="bash" line='line'>
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#!/usr/bin/env python
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sudo apt-get install ros-kinetic-desktop ros-kinetic-ackermann-*
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import rospy
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</syntaxhighlight>
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from sensor_msgs.msg import LaserScan
 
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def is_free(ranges ,start_index, end_index ,min_distance):
 
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#sub array from angle to angle
 
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s_ranges = ranges[start_index:end_index]
 
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#filter the array
 
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b_ranges = filter(lambda x: x <= min_distance, s_ranges)
 
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if len(b_ranges) > 1 : print "BLOCKED"
 
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else : print "FREE"
 
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def callback(msg):    
 
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is_free(msg.ranges,160,200,0.2)
 
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rospy.init_node('scan_values')
 
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#Put your Hamster number instead of agent<number>
 
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#The agent number is printed on the Hamster cover
 
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sub = rospy.Subscriber('/agent14/scan', LaserScan, callback)
 
  
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=== Beginner tutorials ===
  
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rospy.spin()
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* Exercise 1 - [https://wiki.cogni.io/index.php/HamsterPythonExample1 | Process laser Scan ]
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* Exercise 2 - [https://wiki.cogni.io/index.php/HamsterPythonExample2 | Process inertial measurement unit (IMU) ]
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</syntaxhighlight>
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* Exercise 3 - [https://wiki.cogni.io/index.php/HamsterPythonExample3 | Move until collision ]

Latest revision as of 09:21, 24 March 2019


Python setup

  • Note you are connected to the hamster_net (wifi / router)

<syntaxhighlight lang="bash" line='line'> 

$ export ROS_IP=<your IP>

</syntaxhighlight>

<syntaxhighlight lang="bash" line='line'> 

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

</syntaxhighlight>

  • If the Hamster is powered and your terminal is well configured you should be able to

See all data streams <syntaxhighlight lang="bash" line='line'> 

$ rostopic list

</syntaxhighlight> See imagery from the robot <syntaxhighlight lang="bash" line='line'> 

$ rqt_image_view

</syntaxhighlight>

  • Install dependencies

<syntaxhighlight lang="bash" line='line'> sudo apt-get install ros-kinetic-desktop ros-kinetic-ackermann-* </syntaxhighlight>

Beginner tutorials

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