Stretch2 Robot Arm PCB Issue: Gripper and Wrist Motors Not Detected
Description
We’re experiencing issues with our Stretch2 robot, specifically with the gripper and wrist motors not being detected. We suspect a problem with the PCB in the robot’s arm.
Steps to Reproduce
- Run
stretch_robot_home.py - Run
stretch_robot_dynamixel_reboot.py - Directly connect gripper yaw motor to USB using U2D2 adapter
Observed Behavior
When running stretch_robot_home.py:
hello-robot@stretch-re2-2068:~$ 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
[WARNING] [robot]: Not able to use asyncio for transport communications. Defaulting to sync.
--------- Homing Head ----
--------- Homing Lift ----
Homing Lift...
Hardstop detected at motor position (rad) 99.39265441894531
Marking Lift position to 1.100000 (m)
Marking Lift position to 0.000000 (m)
[INFO] [robot_monitor]: Guarded contact lift
[INFO] [robot_monitor]: Wrist single tap: 33
[INFO] [robot_monitor]: Base bump event
[INFO] [robot_monitor]: Wrist single tap: 34
[INFO] [robot_monitor]: Base bump event
[INFO] [robot_monitor]: Base bump event
Lift homing successful
--------- Homing Arm ----
Homing Arm...
[INFO] [robot_monitor]: Wrist single tap: 35
Hardstop detected at motor position (rad) -7.261442184448242
Marking Arm position to 0.000000 (m)
[INFO] [robot_monitor]: Guarded contact arm
[INFO] [robot_monitor]: Wrist single tap: 37
[INFO] [robot_monitor]: Wrist single tap: 38
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
When running stretch_robot_dynamixel_reboot.py:
hello-robot@stretch-re2-2068:~$ 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
[WARNING] [robot]: Not able to use asyncio for transport communications. Defaulting to sync.
Rebooting: head_pan
[Dynamixel ID:011] Reboot Succeeded.
Rebooting: head_tilt
[Dynamixel ID:012] Reboot Succeeded.
Direct connection test:
When bypassing the arm’s PCB and connecting the gripper yaw motor directly to USB via U2D2, an ID scan successfully detected all four Dynamixel motors (yaw, roll, pitch, and gripper).
Expected Behavior
The gripper and wrist motors should be detected and functional when connected through the arm’s PCB.
Additional Context
Based on our tests, we believe the PCB in the robot’s arm may be malfunctioning.
Questions
- Can you confirm if our diagnosis of a faulty PCB in the arm is correct?
- If so, is there a way to repair this PCB?
- Alternatively, how can we obtain a replacement PCB for the Stretch2 robot arm?
We appreciate any guidance on resolving this issue to restore full functionality to our Stretch2 robot. Thank you!