# DynamixelHelloXL430 Ping failed... wrist\_pitch **URL:** \ **Category:** Ask\ **Created:** [February 15, 2024, 5:11pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914 "2024-02-15T17:11:32Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Januxes](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/januxes/32/686_2.png) [@Januxes](https://forum.hello-robot.com/u/Januxes)\ **Post date:** [February 15, 2024, 5:11pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/1 "2024-02-15T17:11:32Z")
Hi, I have been following [this tutorial](https://docs.hello-robot.com/0.3/stretch-install/docs/robot_install/) to install a ubuntu 22.04 system alongside the existing 20.04 system and performed a robot-level install. However, everything worked fine until I ran the shell script: `./stretch_new_robot_install.sh`. I got an error during the creation process for `ament_ws` , probably due to the poor internet environment (I was not using a cable connection for internet but only wi-fi): ```auto ERROR: the following rosdeps failed to install pip: command [sudo -H pip3 install -U torch] failed ``` So I tried to create the `ament_ws` again according to [this tutorial](https://github.com/hello-robot/stretch_install/blob/master/docs/ros_workspace.md): ```auto cd ~\stretch_install ./factory/22.04/stretch_create_ament_workspace.sh -w ~/ament_ws ``` And this worked. I have successfully created the `ament_ws` which can be built and sourced. Then I did the firmware update `REx_firmware_updater.py --install` without any error. I also commented out the following in `~/stretch_user/stretch-re2-xxxx/stretch_configuration_params.yaml` to prevent deprecated warning: ```auto #params: #- stretch_tool_share.stretch_dex_wrist.params ``` But when I moved on to setup the stretch dex wrist, I got the following error when running `REx_calibrate_guarded_contact.py --arm`: ```auto For use with S T R E T C H (R) from Hello Robot Inc. --------------------------------------------------------------------- Joint not calibrated. Exiting. ``` Then I tried to perform the calibration first, but the `stretch_robot_home.py` returns: ```auto For use with S T R E T C H (R) from Hello Robot Inc. --------------------------------------------------------------------- [ERROR] [wrist_pitch]: DynamixelCommError. Mismatched baud rate. Expected 115200 but servo is set to -1. [WARNING] [wrist_pitch]: DynamixelHelloXL430 Ping failed... wrist_pitch DynamixelHelloXL430 Ping failed... wrist_pitch Dnamixel Com error: [ERROR] [robot]: Failed to startup connection to robot ``` Did I miss anything after the creation of ament workspace in `./stretch_new_robot_install.sh`? How can I solve the communication error and could a calibration solve the `Joint not calibrated ` error in `REx_calibrate_guarded_contact.py --arm`? ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [February 15, 2024, 5:49pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/2 "2024-02-15T17:49:31Z")
Hi @Januxes, welcome to the forum! You’re likely correct about a poor internet connection causing the issue initially. I’m glad you were able to create another `ament_ws`. It looks like the reason `stretch_robot_home.py` is failing is because the wrist pitch joint isn’t communicating on the correct baud rate. Let’s start by asking the hardware what baud rate it’s currently using: ```auto REx_dynamixel_id_scan.py /dev/hello-dynamixel-wrist ``` Would you run the above command and share the output here? Additionally, would you tell me the robot’s serial number. ---
**Author:** ![Januxes](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/januxes/32/686_2.png) [@Januxes](https://forum.hello-robot.com/u/Januxes)\ **Post date:** [February 15, 2024, 6:35pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/3 "2024-02-15T18:35:43Z")
Thanks! The serial number is 2031, and this is the output from the scan: ```auto REx_dynamixel_id_scan.py /dev/hello-dynamixel-wrist For use with S T R E T C H (R) from Hello Robot Inc. --------------------------------------------------------------------- Scanning bus /dev/hello-dynamixel-wrist Checking ID 0 Checking ID 1 Checking ID 2 Checking ID 3 Checking ID 4 Checking ID 5 Checking ID 6 Checking ID 7 Checking ID 8 Checking ID 9 Checking ID 10 Checking ID 11 Checking ID 12 Checking ID 13 [Dynamixel ID:013] ping Succeeded. Dynamixel model : XC430-W240. Baud 115200 Checking ID 14 [Dynamixel ID:014] ping Succeeded. Dynamixel model : XL430-W250. Baud 115200 Checking ID 15 Checking ID 16 Checking ID 17 Checking ID 18 Checking ID 19 Checking ID 20 Checking ID 21 Checking ID 22 Checking ID 23 Checking ID 24 Found 2 servos on bus /dev/hello-dynamixel-wrist ``` I also tried `stretch_params.py | grep baud`, which gives 115200 for all devices: ```auto stretch_body.robot_params.nominal_params param.tool_stretch_dex_wrist.baud 115200 stretch_body.robot_params.nominal_params param.tool_stretch_gripper.baud 115200 stretch_body.robot_params.nominal_params param.tool_none.baud 115200 stretch_body.robot_params.nominal_params param.eoa_wrist_dw3_tool_nil.baud 115200 stretch_body.robot_params.nominal_params param.eoa_wrist_dw3_tool_sg3.baud 115200 stretch_body.robot_params.nominal_params param.end_of_arm.baud 115200 stretch_body.robot_params.nominal_params param.head.baud 115200 stretch_body.robot_params.nominal_params param.head_pan.baud 115200 stretch_body.robot_params.nominal_params param.head_tilt.baud 115200 stretch_body.robot_params.nominal_params param.stretch_gripper.baud 115200 stretch_body.robot_params.nominal_params param.wrist_pitch.baud 115200 stretch_body.robot_params.nominal_params param.wrist_roll.baud 115200 stretch_body.robot_params.nominal_params param.wrist_yaw.baud 115200 ``` ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [February 15, 2024, 6:56pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/4 "2024-02-15T18:56:52Z")
Hi @Januxes, it looks like from the output that the wrist pitch and wrist roll joints aren’t present. This might be because your robot doesn’t have the Dex Wrist tool, which was an optional accessory for Stretch 2. Could you take a picture of the tool at the end of the robot’s arm? If your Stretch doesn’t have the Dex Wrist tool, it likely has the Standard Gripper tool. Let me know if you had mistakenly run the `stretch_new_dex_wrist_install.sh` script. ---
**Author:** ![Januxes](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/januxes/32/686_2.png) [@Januxes](https://forum.hello-robot.com/u/Januxes)\ **Post date:** [February 15, 2024, 7:19pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/5 "2024-02-15T19:19:19Z")
Here is the picture: ![image](https://canada1.discourse-cdn.com/flex030/uploads/hello_robot2/original/1X/3c0e43c054541e75e396e569cc82107c15ad0462.jpeg) I just noticed that on the side of the wrist there is an LED blinking yellow light: ![image](https://canada1.discourse-cdn.com/flex030/uploads/hello_robot2/original/1X/2a3af829c0d01bf962736b2a28a3ad1c339a3bb3.jpeg) ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [February 15, 2024, 9:53pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/6 "2024-02-15T21:53:05Z")
Hi @Januxes, thanks, that tool is called the “Standard Gripper”. The blinking yellow LED on the side of the wrist is innocuous. Here are instructions to change the tool your robot is configured to use: 1. Edit `stretch_configuration_params.yaml` in your robot data directory to change the `robot.tool` parameter. It should look like this: ```yaml robot: tool: tool_stretch_gripper ``` 2. Create a URDF that includes the standard gripper tool using [these instructions](https://github.com/hello-robot/stretch_ros2/tree/humble/stretch_description#changing-the-tool). You should be able to home the robot now. Let me know if you have any questions. ---
**Author:** ![Januxes](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/januxes/32/686_2.png) [@Januxes](https://forum.hello-robot.com/u/Januxes)\ **Post date:** [February 15, 2024, 11:13pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/7 "2024-02-15T23:13:10Z")
Thanks! I changed the tool setting in the .xacro file, built the workspace again and it worked! Sorry I mistaken the standard gripper for Dex Wrist. Now I finally can home the robot and calibrate it correctly. ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [February 15, 2024, 11:15pm UTC](https://forum.hello-robot.com/t/dynamixelhelloxl430-ping-failed-wrist-pitch/914/8 "2024-02-15T23:15:46Z")
No worries @Januxes! Glad you got it all working!