nishthapa's profile - activity

I have a scenario in which i have to take readings from a DHT11 Temperatute & Humidity sensor and publish it to a topic (I am using python so suggestions keeping python in mind would be helpful). The problem is that i need to do sudo to assess the GPIO but again rosrun is not found when in sudo. What should i do ?

Glad I could be of help.

Hey guys, I have sucsessfully set up an apache2 server on a Raspberry Pi 2. It hosts a simple webpage which I created. All this webpage does is that it connects to the ws://ww.xx.yy.zz:9090 of my rosbridge_server websocket which is also running on the Pi. I can access the webpage from the internet but the webpage does not connect to rosbridge_server (websocket). (I have made all the port forwarding and other required settings on my router). Please help me. Here is the JavaScript Console error message from my browser:

WebSocket connection to 'ws://ww.xx.yy.zz:9090/' failed: Error in connection establishment: net::ERR_CONNECTION_TIMED_OUT
Error connecting to websocket server

Connection to websocket server closed.

I am not being able to import even the basic libraries such as with from std_msgs import Stringsin my python scripts. Please help me fix this issue.

EDIT

This is my CMakeLists.txt :

cmake_minimum_required(VERSION 2.8.3)
project(ior_internet)

find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
std_msgs
)

catkin_package
(
 ##INCLUDE_DIRS include
 ##LIBRARIES ior_internet
 ##CATKIN_DEPENDS roscpp rospy std_msgs
 ##DEPENDS system_lib
)

And this is my package.xml :

<?xml version="1.0"?>
<package>
<name>ior_internet</name>
<version>0.0.0</version>
<description>The ior_internet package</description>

<license>TODO</license>

<buildtool_depend>catkin</buildtool_depend>
<build_depend>roscpp</build_depend>
<build_depend>rospy</build_depend>
<build_depend>std_msgs</build_depend>
<run_depend>roscpp</run_depend>
<run_depend>rospy</run_depend>
<run_depend>std_msgs</run_depend>

</package>

Predrucius, if you mean the internet (a webpage), and the Master node then you will have to keep your master node under a port forwarded router having a public IP. And of course you will have to code the webpage (with JavaScript) yourself. If you want more help, mail me.

The machine has apache2 and ROS Master. I have also built a Wordpress site on the same machine. What i want to do is to access that wordpress site from the internet (i will buy a router) and use it to send messages to and receive from the ROS Master. Any ideas ?

Here is what I get on sudo apt-get install ros-indigo-rosbridge-suite

Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package ros-indigo-rosbridge-suite

Thank you for the quick answer. Installing qtbase5-dev solved my problem.

Hello guys, I have been trying to install rqt features (such as rqt_plot and rqt_graph) in a Minimal ROS installation (not the full desktop) my Raspberry Pi 2 from source. I have been resolving dependencies all night but now I am stuck. When the package rqt_gui_cpp is being built with catkin_make , the following error keeps creeping up. What should i do ?

-- +++ processing catkin package: 'qt_gui_cpp'
-- ==> add_subdirectory(qt_gui_core/qt_gui_cpp)
-- Boost version: 1.55.0
-- Found the following Boost libraries:
--   filesystem
--   system
CMake Error at qt_gui_core/qt_gui_cpp/src/qt_gui_cpp/CMakeLists.txt:3 (find_package):
By not providing "FindQt5Widgets.cmake" in CMAKE_MODULE_PATH this project
has asked CMake to find a package configuration file provided by
"Qt5Widgets", but CMake did not find one.

Could not find a package configuration file provided by "Qt5Widgets" with
any of the following names:

  Qt5WidgetsConfig.cmake
  qt5widgets-config.cmake

Add the installation prefix of "Qt5Widgets" to CMAKE_PREFIX_PATH or set
"Qt5Widgets_DIR" to a directory containing one of the above files.  If
"Qt5Widgets" provides a separate development package or SDK, be sure it has
 been installed.


-- Configuring incomplete, errors occurred!
See also "/home/pi/ros_catkin_ws/build/CMakeFiles/CMakeOutput.log".
See also "/home/pi/ros_catkin_ws/build/CMakeFiles/CMakeError.log".
Makefile:7390: recipe for target 'cmake_check_build_system' failed
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed

I wonder if NRF24L01 modules would help as they are tranceivers. All i want to do is make the usb cable connection wireless.

No, I already have a 433 MHz TX-RX radio pair. I dont want xbee. And the maximum bandwidth i would want is about 100bytes/sec which the rf pair can easily handle. I have even tried it out for arduino to arduino communication.

I have an arduino which i want to use as RF receiver and a Raspberry Pi 2 which will act as RF transmitter. The problem is that I just want to replace the USB cable from RPI to arduino with a 433 MHz Tx-Rx pair. I want to do it as USB Serial as i only need to transmit low volumes of data. I also have a USB to Serial converter which I think I may need.In short, i just want to make the process wireless with RF Communication. Please help me out.

EDIT

I dont want to program the arduino over RF or anything but just send data from a running python node like this :

 RPI(ROS Python Node) ---> USB to Serial Converter ---> RF Transmitter ---> Air ---> RF Receiver ---> Arduino

Yes but currently, I dont need the common_msgs but only diagnostic_msgs so I only installed diagnostic_msgs.

Hello guys, I built ROS indigo on my pi 2 and tried to use the rosserial_arduino (after making my workspace having rosserial metapackage with catkin_make install). The problem is that whenever i try to initialize serial communication with an arduino with rosrun rosserial_python serial_node.py /dev/ttyACM0,it just says : No such file or directory. I checked my ports with ls /dev and my arduino is on ttyACM0. Please help me out.

EDIT

This problem was solved by rebuilding my workspace with catkin_make install but new errors have crept up again :

This is the error now on executing rosrun rosserial_python serial_node.py /dev/ttyACM0

Traceback (most recent call last):
File "/home/pi/ros_catkin_ws/src/rosserial/rosserial_python/nodes/serial_node.py", line 39, in <module>
from rosserial_python import SerialClient, RosSerialServer
File "/home/pi/ros_catkin_ws/devel/lib/python2.7/dist-packages/rosserial_python/__init__.py", line 35, in <module>
exec(__fh.read())
File "<string>", line 1, in <module>
File "/home/pi/ros_catkin_ws/src/rosserial/rosserial_python/src/rosserial_python/SerialClient.py", line 51, in <module>
import diagnostic_msgs.msg
ImportError: No module named diagnostic_msgs.msg

Hey guys i solved it. All i had to do was rebuild my workspace with catkin_make install and install the diagnostic_msgs package into a source built ROS distribution. Thank you all for your help.