ROS Tutorial 3

Hello everyone,

I am working on ROS tutorial 3. However, after I uploaded the provided code and ran
$ /opt/husarion/tools/rpi-linux/ros-core2-client /dev/ttyCORE2
$ rosrun teleop_twist_keyboard
the ROSbot doesn’t move when I issue commands in the terminal.
Running rqt_graph gives me ‘libEGL warning:DRI2 fails to authenticate’ but the graph itself shows up and is the same as the graph in the tutorial except that /diagnostic isn’t there.
Furthermore, ‘$ /opt/husarion/tools/rpi-linux/ros-core2-client /dev/ttyCORE2’ gives me:
[INFO] [1525425289.841859]: ROS Serial Python Node
[INFO] [1525425289.858312]: Connecting to /dev/ttyCORE2 at 500000 baud
[INFO] [1525425292.045754]: Note: subscribe buffer size is 512 bytes
[INFO] [1525425292.046715]: Seup subscriber on /cmd_vel [geometry_msgs/Twist]
Could someone help me with this?


Hello Eric,

Output from ‘$ /opt/husarion/tools/rpi-linux/ros-core2-client /dev/ttyCORE2’ is correct.
Please make sure that messages from teleop_twist_keyboard are sent by:
$ rostopic echo /cmd_vel

Also, make sure, that you have batteries fully charged - motors will be disabled when supply voltage is lower than 11.1V. Low voltage is indicated with LED L1 blinking.

Łukasz Mitka

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