रास्पबेरी पाई पर आरओएस का व्यावहारिक उपयोग - भाग 2

कैमरा आरपीआई कैमरा बोर्ड

पुस्तकालय स्थापना

$ sudo apt-get install libopencv-dev

$ tar xvzf raspicamxx.tgz
$ cd raspicamxx
$ mkdir build
$ cd build
$ cmake ..
$ make
$ sudo make install
$ sudo ldconfig

$ sudo raspi-config

आरओएस के साथ शुरू हो रही है

$ mkdir -p ~/driverobot_ws/src
$ cd ~/driverobot_ws/src
$ catkin_init_workspace
$ cd ~/driverobot_ws
$ catkin_make

$ cd src/
$ catkin_create_pkg raspi_cam_ros image_transport cv_bridge roscpp std_msgs sensor_msgs compressed_image_transport opencv2

$ curl http://www.linux-projects.org/listing/uv4l_repo/lrkey.asc | sudo apt-key add -

deb http://www.linux-projects.org/listing/uv4l_repo/raspbian/ wheezy main

$ sudo apt-get update
$ sudo apt-get install uv4l uv4l-raspicam

$ sudo apt-get install uv4l-raspicam-extras

link_directories(/usr/lib/uv4l/uv4lext/armv6l/)
…
target_link_libraries(capture ${catkin_LIBRARIES} uv4lext)

add_executable(capture src/capturer.cpp)
target_link_libraries(capture ${catkin_LIBRARIES} uv4lext)

<?xml version="1.0"?>                                                                                            
<package>                                                                                                        
  <name>raspi_cam_ros</name>                                                                                      
  <version>0.0.0</version>                                                                                       
  <description>The raspi_cam_ros package</description>                                                            
                                                                                                                 
  <maintainer email="pi@todo.todo">pi</maintainer>                                                               
                                                                                                                 
  <license>TODO</license>                                                                                        
  <buildtool_depend>catkin</buildtool_depend>                                                                    
  <build_depend>cv_bridge</build_depend>                                                                         
  <build_depend>image_transport</build_depend>                                                                   
  <build_depend>roscpp</build_depend>                                                                            
  <build_depend>std_msgs</build_depend>                                                                          
  <build_depend>sensor_msgs</build_depend>                                                                       
  <build_depend>opencv2</build_depend>                                                                           
  <build_depend>compressed_image_transport</build_depend>                                                        
  <run_depend>cv_bridge</run_depend>                                                                             
  <run_depend>image_transport</run_depend>                                                                       
  <run_depend>roscpp</run_depend>                                                                                
  <run_depend>std_msgs</run_depend>                                                                              
  <run_depend>sensor_msgs</run_depend>                                                                           
  <run_depend>opencv2</run_depend>                                                                               
  <run_depend>compressed_image_transport</run_depend>                                                                                                                                                                    
</package>

ros::init(argc, argv,"raspi_cam_ros");
ros::NodeHandle n;
UsbCamNode a(n);
a.spin();

$ uv4l --driver raspicam --auto-video_nr --width 640 --height 480 --nopreview

$ roscore
$ cd ~/driverobot_ws
$ catkin_make

echo $ROS_PACKAGE_PATH
/opt/ros/indigo/share:/opt/ros/indigo/stacks

$ source devel/setup.bash

/home/youruser/catkin_ws/src:/opt/ros/indigo/share:/opt/ros/indigo/stacks

$ rosrun raspi_cam_ros capture

$ rosrun rqt_image_view rqt_image_view

$ ssh -X pi@<host_pi>

rostopic hz image_raw

average rate: 7.905
              min: 0.075s max: 0.249s std dev: 0.02756s 

average rate: 30.005
              min: 0.024s max: 0.043s std dev: 0.00272s 

OpenCV और ROS के साथ दृश्य-आधारित रोबोट नियंत्रण

#include <std_msgs/Int16.h>

std_msgs::Int16 shift_msg;

ros::Publisher shift_pub;

shift_pub = nh.advertise<std_msgs/Int16>(“line_shift”, 1);

// Some logic for the calculation of offest
shift_msg.data = offset;
shift_pub.publish(shift_msg);

$ rosmsg show std_msgs/Int16

$ rosrun raspi_cam_ros capturer

$ rostopic echo line_shift

#include <std_msgs/UInt16.h>

void messageCb(const std_msgs::UInt16& message) 
{
  int shift_val = int(message.data);
  
  char* log_msg;
  if(shift_val < 0) log_msg = "Left";
  else if(shift_val > 0 ) log_msg = "Right";
  else log_msg = "Forward";
  
  nh.loginfo(log_msg);
}

ros::Subscriber<std_msgs::UInt16> sub("line_shift", &messageCb);

void setup()
{
  nh.initNode();
  nh.subscribe(sub);
  
  Serial.begin(57600);
}

void loop()
{
  nh.spinOnce();
  delay(100);
}

$ cd <catkin_ws>/src
$ catkin_create_pkg rosserial_controller
$ cd src/rosserial_controller
$ vim rosserial_controller.launch

<launch>
 <node pkg="rosserial_python" type="serial_node.py" name="arduino_serial">
       <param name="port" value="/dev/ttyACM0"/>       
 </node>
</launch>

$ cd ~/<catkin_ws>
$ catkin_make
$ source devel/setup.bash
$ roslaunch rosserial_controller rosserial_controller.launch

$ rqt_plot line_shift