UW NDCL's profile - activity

This seems to be the case. For some reason, the system is unable to connect to the network, even on a wired connection.

We're trying to install ros on a new system, but during the key setup step, ubuntu is responding with an error claiming

wget: unable to resolve host address 'packages.ros.org'
gpg: no valid OpenPGP data found.

This occurs after attempting to execute

wget http://packages.ros.org/ros.key -O - | sudo apt-key add -

The same problem came up about a week ago on a different system, but it was fixable using

sudo gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv A258828C

(Which was scrounged up from the depths of an old wiki post)

However, this no longer works. Before this month, OpenPGP has never appeared during the ros installation process, but is now making it impossible to complete installation. Is there an easy way to resolve this?

We're trying to communicate via publisher/subscriber nodes between a laptop and a PC-104, but whenever we try to send a message, this error is returned:

QMetaObject::connectSlotsByName: No matching signal for on_button_move_to_clicked(int) file = /opt/ros/fuerte/include/ros/publisher.h line = 102 cond = false message = Trace/breakpoint trap

Which is generated by this line in publisher.h:

  if (!impl_)
     {
       ROS_ASSERT_MSG(false, "Call to publish() on an invalid Publisher");
       return;
     }

But we're not sure what "!impl_" means, so we can't figure out what exactly is triggering this error. Has anyone dealt with this before?

http://mirror.umd.edu/roswiki/doc/api/roscpp/html/publisher_8h_source.html (Full text of publisher.h)

For our current project, we created a launch file that initializes several nodes, one of which is supposed to create a log file, open it, write a header line at the beginning of the file, and then close the file.

When we run the nodes individually from terminal, this function works fine, but when the project is run from a launch file, the log file is never created. Do nodes run from a launch file not have permission to create new log files?

Function to create log file:

char Beacon::createLogFile(char *logDataFileName)

{

int status;
status = mkdir("Log", S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);

if (status == -1)
{
        // error; it might be that the directory already exists
        if (errno == EEXIST)
        {
            // no problem
        }
        else if (errno == EACCES)
        {
            printf("Permission\n");
                return 1;
        }
}
else
{
        // Directory successfully created

}

FILE* logData_f_stream;
logData_f_stream = fopen(logDataFileName, "w");

fprintf(logData_f_stream, "NodeID Latitude Longitude Time OWTT\n");
fclose(logData_f_stream);


return 0;

}