TillScout's profile - activity

Have you been successful already? I am curious about the performance of ROS on Ubuntu Touch devices.

What do you mean by "connect it correctly"?

I have a custom built Turtlebot with an iRobot Create. However I do not have a serial to USB adapter.

How can I use the serial cable of the Create for my Turtlebot? I already found out that in turtlebot_node.py the port for the Create is set to ttyUSB0. What do I have to change here, so that I can use the serial port? Do I have to change anything else?

oops, I just wanted to reproduce the error, but now it works. Nevermind.

I installed the Turtlebot stack on both my Ubuntu 12.04 Turtlebot computer and my workstation, but I cannot start the turtlebot dashboard. Is that not yet ported to Fuerte?

ok, I was expecting that. I hope that it is possible to run a full ROS installation on a strong master but have several Pi slaves with only low level functionality that take care of certain tasks only (like a Pi that does only arm navigation in a more complex robot that runs a quadcore master or so)

Great job! Will definitely try as soon as my Pi arrives. Even when it is slow, do you think it is usable when you distribute ROS-nodes over several Raspberry Pis?

@patrick_hammer How does your solution work? How do you power the mini ITX board? Maybe you can post some more details on your project.

Try this:

rostopic pub /array_test playground/Arrays "{name:['Foo', 'Bar'], value:[1.1, 2.2]}"

EDIT - the inner quotes don't seem to be required, even with spaces in the string, so this also works:

rostopic pub /array_test playground/Arrays "{name:[Some words, More words], value:[1.1, 2.2]}"

Hi all,

I am new to ROS and experimenting with several things. Now I have the following problem: I want to define a topic where the type contains arrays of strings and floats. So I wrote a file Arrays.msg that contains

string[] name
float32[] value

and a simple Subscriber node:

import roslib; roslib.load_manifest("playground")
import rospy
from playground.msg import Arrays

def callback(data):
        print "test"

def main():
        rospy.init_node("array_test_node")
        sub = rospy.Subscriber("array_test", Arrays, callback)
        rospy.spin()

if __name__ == "__main__":
        main()

Now my question is: How do I publish a list of strings and floats on the command line? It works when I type

rostopic pub /array_test playground/Arrays -- ["Foo"] [1.1]

and it publishes the correct message on /array_test. But what if I have more strings? I tried

rostopic pub /array_test playground/Arrays -- ["Foo", "Bar"] [1.1, 2.2]

but I get the following error message:

rostopic: error: Argument error: while parsing a flow node
expected the node content, but found '<stream end>'
    in "<string>", line 1, column 6:
    [Foo,
         ^

What would be the correct command for publishing these arrays on the command line?

Thanks!