Servo ID resets when motor plugged in?

[jloganolson]

Hello, when I unplug a motor and plug it back in, it seems the ID resets to 1?

[lucas-vitrus]

I literally just got the same problem, using the

motor.servo_ref.eeprom.write_id(new_id)

and when I turn off the motor and try again, the ID resets to 1 again (default)

[lucas-vitrus]

Okay, I found the problem:

I tested it a few times and it worked.

If you want install it from this fork: https://github.com/lucas-vitrus/python-st3215

pip install git+https://github.com/lucas-vitrus/python-st3215.git

Or wait for an update on this (I saw a 1.0.1v PR open but it doesn't seem this issue was addressed);

@alessiodam thanks for the lib btw! Super helpful.

[alessiodam]

Thanks a lot for contributing! I'll get to testing your patch and merging it today ;)

[alessiodam]

@lucas-vitrus please submit a PR on branch dev so that I can merge it later :)

[alessiodam]

Fixed in #3, thank you @lucas-vitrus! It will get merged in version 1.1.0 ;)

[alessiodam]

@lucas-vitrus and @jloganolson, I've published v1.1.0, you can view it here.

[jloganolson]

Hello, this did not appear to fix the issue - repro steps:

Confirm motor is ID 1:

import os
from dotenv import load_dotenv
from python_st3215 import ST3215, ServoNotRespondingError

load_dotenv()

controller = ST3215(os.getenv("ST3215_PORT", "/dev/ttyACM0"))

try:
    servo = controller.wrap_servo(1)
    print("Current location:", servo.sram.read_current_location())
except ServoNotRespondingError:
    print("Servo not responding")
finally:
    controller.close()

Change ID:

import os
from dotenv import load_dotenv
from python_st3215 import ST3215

load_dotenv()

OLD_ID = 1
NEW_ID = 2

controller = ST3215(os.getenv("ST3215_PORT", "/dev/ttyACM0"))

try:
    print("=" * 60)
    print("CHANGE SERVO ID")
    print("=" * 60)
    print("\nWARNING: Only connect ONE servo to avoid ID conflicts!")
    print(f"This will change servo ID from {OLD_ID} to {NEW_ID}")

    response = input("\nType 'yes' to continue: ")
    if response.lower() != "yes":
        print("Cancelled.")
    else:
        servo = controller.wrap_servo(OLD_ID)

        print(f"\nCurrent ID: {servo.eeprom.read_id()}")
        print(f"Changing to ID {NEW_ID}...")

        servo.eeprom.write_id(NEW_ID)

        print("\nVerifying change...")
        new_servo = controller.wrap_servo(NEW_ID)
        confirmed_id = new_servo.eeprom.read_id()

        if confirmed_id == NEW_ID:
            print(f"✓ Successfully changed to ID {NEW_ID}")
        else:
            print(f"✗ Failed to change ID (read: {confirmed_id})")
finally:
    controller.close()

Unplug motor and replugin then run first script with ID 2 (wrap_servo(2) not found) and ID 1 (found)

[lucas-vitrus]

@jloganolson can you try from this branch?

pip install git+https://github.com/lucas-vitrus/python-st3215.git

This is what I used on mine and they worked. Not sure if I made a mistake on the PR or what.

[alessiodam]

I tested before merging anything and it did work. Maybe there's something wrong on your end? Can you confirm you've installed 1.1.0 @jloganolson ?

[jloganolson]

Yes, confirmed - ultimately used the first party feetech software to change id

…

On Tue, Dec 23, 2025, 12:54 AM alessiodam ***@***.***> wrote: *alessiodam* left a comment (alessiodam/python-st3215#2) <#2 (comment)> I tested before merging anything and it did work. Maybe there's something wrong on your end? Can you confirm you've installed 1.1.0 @jloganolson <https://github.com/jloganolson> ? — Reply to this email directly, view it on GitHub <#2 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADNPOLR3NC5W66YU4HLMNOD4DD7MLAVCNFSM6AAAAACN7CPNOWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMOBVG44DKOJZHE> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[alessiodam]

Weird, the example script provided here works.