Need to resolve rosserial rostopic echo chatter not published yet
After uploading the Hello World sketch to my Arduino Uno per the rosserial tutorial, I'm getting this "rostopic echo chatter WARNING: topic [/chatter] does not appear to be published yet".
I'm a real beginner with ROS, so hopefully someone has a link to the solution.
Thanks in advance
RoboBill
Asked by RoboBill on 2014-12-28 23:24:38 UTC
Answers
When you run rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB1 you should get something like so:
$ rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB1
[INFO] [WallTime: 1420480219.434646] ROS Serial Python Node
[INFO] [WallTime: 1420480219.437731] Connecting to /dev/ttyUSB1 at 57600 baud
/opt/ros/indigo/lib/python2.7/dist-packages/rosserial_python/SerialClient.py:336: SyntaxWarning: The publisher should be created with an explicit keyword argument 'queue_size'. Please see http://wiki.ros.org/rospy/Overview/Publishers%20and%20Subscribers for more information.
self.pub_diagnostics = rospy.Publisher('/diagnostics', diagnostic_msgs.msg.DiagnosticArray)
[ERROR] [WallTime: 1420480219.439001] Error opening serial: could not open port /dev/ttyUSB1: [Errno 2] No such file or directory: '/dev/ttyUSB1'
Asked by tonybaltovski on 2015-01-05 12:52:47 UTC
Comments
Wow... I get nothing like that. Should I uninstall then re-install ROS or is there a fix I can run?
Asked by RoboBill on 2015-01-06 13:35:24 UTC
What do you get?
Asked by tonybaltovski on 2015-01-06 14:59:48 UTC
I get nothing... sorry... I type roscore...(with the correct response) then I type in your command and ... nothing... darn
Asked by RoboBill on 2015-01-06 18:08:04 UTC
Finally!... not sure why but I typed in your command in a new terminal and got a response...
Asked by RoboBill on 2015-01-06 18:13:03 UTC
THE SAME PROBLEM HERE IF PLEASE ANY ONE HELP WHEN I RUN ""rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB1"" NO thing is done
Asked by sazuddin on 2015-06-19 23:17:53 UTC
I believe I've figured it out. The tutorial did not specify that each instruction was to be entered into a new terminal. Once I did that I got data hello world
Thanks Tony for your patients
RoboBill
Asked by RoboBill on 2015-01-06 21:37:04 UTC
Comments
Did you run the serial_node?
Asked by tonybaltovski on 2014-12-29 00:38:15 UTC
Hi Tony,
I followed the instructions per the rosserial tutorial...
in a terminal I ran... 1) roscore 2) rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB1 3) In a new terminal.... rostopic echo chatter... thats where it "burps"
RoboBill
Asked by RoboBill on 2014-12-29 01:21:32 UTC
Is your Arduino connected /dev/ttyUSB1?
Asked by tonybaltovski on 2014-12-29 04:31:03 UTC
Yes... I uploaded the sketch successfully with the Arduino IDE via USB1
Asked by RoboBill on 2014-12-29 10:11:50 UTC
Hi Tony,
I just remembered I changed the bootloader on this Uno a few months back. So when I upload a sketch to this Uno, I choose the board type as a Duemilanove w/ ATmega328.
Does this help?
Asked by RoboBill on 2014-12-29 12:41:55 UTC
What does the serial_node output? Does it connect?
Asked by tonybaltovski on 2014-12-29 14:38:34 UTC
Hi Tony,
I get the following:
WARNING: topic [/chatter] does not appear to be published yet
Thanks
RoboBill
Asked by RoboBill on 2014-12-30 14:54:50 UTC
I meant, what output do you get from the serial_node?
Asked by tonybaltovski on 2015-01-04 23:11:38 UTC
Hi Tony,
First ... thank you for your time. I am not a programmer... so a majority of this is way over my head...
OK. to your question...
if you mean what happens after I type in "rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB1" Nothing happens.. is there a link to help me with that?
Asked by RoboBill on 2015-01-05 12:40:12 UTC