Can't access turtlebot through ttyUSB0

Question

Hi,

I think that ROS can't access my Create... Is not possible see informations about the robot in turtlebot_dashboard, like battery and sensors status, but is possible to see netbook battery status, then I can conclude that the connection Workstation-netbook is ok, the problem could be between the netbook and Create. The status of all sensors in turtlebot_dashboard is Stale, except the netbook battery.

I'm using a serial-usb converter, because my Create uses a serial-serial cable. Could it be the problem?

Using "dmesg" and "lsusb" commands, I can see that my converter is properly connected at ttyUSB0. And I've tried to change the default_port in turtlebot_node.py to another USB and serial ports, but the error continues.

Thanks in advance, Lucas

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Originally posted by lucascoelho on ROS Answers with karma: 497 on 2011-09-12

Post score: 2

Answer 1

I think I had the same problem with the ATHEN USB serial cable. Here is how I solved it:

Add the following line in the /etc/udev/rules.d/52-turtlebot.rules:

ATTRS{idProduct}=="2008",ATTRS{idVendor}=="0557",MODE="666",GROUP="turtlebot"

2008 and 0557 is either the vendor or product id. You can find that out from lsusb. The problem is that the ttyUSB0 does not have the approprite permission.

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Originally posted by dvbot with karma: 86 on 2011-09-12

This answer was ACCEPTED on the original site

Post score: 7

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Original comments

Comment by lucascoelho on 2011-11-25:
Have you tried to edit the file as a superuser (root)?

Comment by MovieMaker on 2011-11-23:
I am having the same darn problem that I had on the other one. I can pull up the file and make changes, but I cannot save the new file.

Comment by lucascoelho on 2011-09-13:
Thanks a lot!!!! Now everything is ok on my turtlebot!

Comment by Ozkan on 2012-05-02:
I had a similar problem. I followed the instructions here, and got my turtlebot working for a day. I shutdown everything at the weekend. On monday, I was back to zero. I am getting "Failed to open port /dev/ttyUSB0" What can cause this?

Comment by Sentinal_Bias on 2013-06-04:
Hi is GROUP="xxx" referring to the login account?

Comment by vikiboy on 2014-06-30:
Bus 003 Device 005: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC

What shall be my required code ? and could u tell me the parameters for GROUP and MODE ?

Answer 2

I had a similar problem, and I'd like to add something to dvbot's extremely helpful response. I couldn't communicate to the my turtlebot netbook, and my Turtlebot Dashboard was all gray. Under Diagnostic, I had the error: TurtleBot Node: Failed to open port /dev/ttyUSB0. Please make sure the Create cable is plugged into the computer.

When trying to implement dvbot's recommendation, I realized my turtlebot netbook didn't have the file /etc/udev/rules.d/52-turtlebot.rules, and I did not have permission to create it. I went here, and found good instructions from tredegar (halfway down the page) in how to overcome the problem. For your convenience, I am recopying some of tredegar's recommendation. To become root issue the command:

sudo -i

Then to create the file you can use the command

gedit /etc/udev/rules.d/52-turtlebot.rules

or use your favorite editor. Once you populate the content with dvbot's code, restart udev:

/etc/init.d/udev  restart

I'm still very new to this, but I do know this worked for me: once I restarted udev, my Turtlebot Dashboard went from gray to greens and reds. Both my workstation and turtlebot netbook are running Ubuntu 11.10 and ros electric. Hope this is useful.

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Originally posted by trroy with karma: 21 on 2012-03-06

This answer was NOT ACCEPTED on the original site

Post score: 2