Stretch gripper and yaw not homing

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1

I started my robot and can’t home the gripper. Here are the logs:

hello-robot@stretch-re2-2003:~$ stretch_robot_dynamixel_reboot.py 
For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc.
---------------------------------------------------------------------

[WARNING] [stretch_gripper]: DynamixelHelloXL430 Ping failed... stretch_gripper
DynamixelHelloXL430 Ping failed... stretch_gripper
Rebooting: head_pan
[Dynamixel ID:011] Reboot Succeeded.
Rebooting: head_tilt
[Dynamixel ID:012] Reboot Succeeded.

Dynamixel servo reboot complete. You will need to re-home servos now.
hello-robot@stretch-re2-2003:~$ stretch_robot_home.py 
For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc.
---------------------------------------------------------------------

[WARNING] [stretch_gripper]: DynamixelHelloXL430 Ping failed... stretch_gripper
DynamixelHelloXL430 Ping failed... stretch_gripper
--------- Homing Head ----
--------- Homing Lift ----
Homing Lift...
Hardstop detected at motor position (rad) 115.06414794921875
Marking Lift position to 1.098445 (m)
Marking Lift position to 0.000000 (m)
Lift homing successful
--------- Homing Arm ----
Homing Arm...
Hardstop detected at motor position (rad) -0.2050761878490448
Marking Arm position to 0.000000 (m)
Arm homing successful
[WARNING] [stretch_gripper]: Not able to home stretch_gripper. Hardware not present
[WARNING] [wrist_yaw]: Not able to home wrist_yaw. Hardware not present

Things I tried:

  • restarting Stretch, but the error persists.
  • checking if the hardware wires are correctly connected and not damaged.
2

Hey @Vidhi_Jain

These warnings usually pop up when the three wires going into the wrist Dynamixels have come loose. It is worth disconnecting and then reconnecting the 3-pin connector and then trying again.

To do this follow the steps:

  1. Completely power down the robot
  2. Disconnect the 3-pin connector on the wrist Dynamixel by gently tugging on it
  3. Firmly reconnect the 3-pin connector
  4. Power on the robot
  5. Run stretch_robot_home.py in a terminal

Let me know what you find.

Best,
Chintan Desai

3

I disconnected and replaced one of the 3-pin connector Dynamixel wire and reconnected the others, but the issue still persists.

4

IMG_0348.HEIC
IMG_0348.HEIC3024×4032 2.18 MB

The light on the gripper was earlier flashing red. After reconnecting and replacing dynamixel wires, it shows no light at all.
I believe this would be white light in normal circumstances, isn’t it?

5

I ran REx_dynamixel_id_scan.py /dev/hello-dynamixel-wrist and it detects 0 servos.
REx_dynamixel_id_scan.py /dev/hello-dynamixel-head works as expected, by finding 2 servos on id 11,12.

Does this mean that the dynamixel is somehow damaged?