IOError on wrist when changing tool

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1

I followed the steps outlined to change the tool to the dry erase marker tool provided here as an exercise before changing to our custom tool, but when executing:

$ rosrun stretch_calibration update_urdf_after_xacro_change.sh

The output said it finished but the process seems to hang and not finish so I used ctrl c to return to the command line in order to run the following roslaunch command. When running the roslaunch command or trying to run stretch_robot_home.py I got the following error message:

IOError on: /dev/hello-dynamixel-wrist

which also means when running stretch_robot_system_check.py that not everything was calibrated. It seems to me that the rosrun command isn’t actually updating the URDF file to include the new tool, and still expects the original gripper. I was able to still run a simple program that involved moving the base, lift, and arm, but I want to make sure I’m not doing something wrong that could harm the robot.

2

Great to see that you’re exploring new tools! It is normal to have to Ctrl-C out of the URDF update script. I believe that the robot is still looking for the gripper (which I presume has been removed).

Take a look in your ~/stretch_user/stretch-re1-xxxx/stretch_re1_user_params.yaml. You’ll want to comment out the section that reads:

end_of_arm:
devices:
stretch_gripper:
py_class_name: StretchGripper
py_module_name: stretch_body.stretch_gripper

Let us know how it goes. (By the way, there is new Stretch Body and Stretch ROS functionality coming out soon that will allow for easier changing of tools).

3

Yes, this fixed the error message. Thanks!