ST3215 All Motors Undetectable After Manual Bac... | AIFITLAB Community Forum

ST3215 All Motors Undetectable After Manual Backdrive During Teleoperation - Need Help


  • Hello everyone,

    I'm in a difficult situation and would really appreciate any help. I have 6 ST3215 30kg.cm serial bus servo motors from Waveshare that completely stopped responding after I accidentally manually moved my robot arm while testing teleoperation.

    WHAT HAPPENED:
    I was testing teleoperation with phosphobot software, controlling my SO-101 robotic arm, when I made a mistake and manually back-drove the arm while the motors were still powered and actively controlled. The moment I did this, all 6 motors instantly lost communication. They still receive power (the red LED is solid on all motors, and I measure 12V at the terminals), but no software can detect them anymore.

    THE TRIGGER:
    - I was running phosphobot for teleoperation testing
    - I manually moved the robot arm while motors were powered and under active control
    - Result: Complete loss of communication with all 6 motors at the same time

    WHAT I'VE TRIED SO FAR:
    - Extended power cycle - unplugged both 12V and USB for over 10 minutes
    - Tested every baud rate: 1000000, 500000, 115200, 57600, 38400, 19200
    - Used FD SCServo Debug Qt software - Search finds absolutely nothing
    - Tried LeRobot framework motor scan - Failed, no motors detected
    - Switched USB ports and cables multiple times
    - Double-checked all connections - everything is secure
    - Measured voltage at the motors - 12V is definitely present
    - Ran motor ID scan from 0 to 253 - Not a single response
    - The Waveshare driver board itself is working fine (LED on, /dev/ttyACM0 shows up)

    CURRENT STATUS:
    - Power: Motors are getting 12V, red LED is solid on each motor
    - Physical condition: Motor shafts rotate freely by hand, which tells me torque is disabled
    - Communication: Completely dead. No Ping response, no ID detection, nothing
    - All 6 motors affected at exactly the same time
    - This happened during an active teleoperation session

    MY SETUP:
    - Motors: ST3215 30kg.cm (Waveshare Serial Bus Servo)
    - Controller: Waveshare Serial Bus Servo Driver Board
    - Operating System: Ubuntu 22.04 LTS
    - Software: phosphobot (teleoperation), LeRobot framework, FD SCServo Debug Qt
    - Power Supply: 12V 5A DC
    - Connection: USB-C to laptop (shows as /dev/ttyACM0)
    - Robot: SO-101 6DOF robotic arm

    Technical:
    - Project: SO-101 robotic arm teleoperation with LeRobot
    - Software: phosphobot, LeRobot framework
    - Hardware: 6x ST3215 30kg.cm, Waveshare Serial Bus Servo Driver Board
    - OS: Ubuntu 22.04 



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