bluetooth.btcommon.BluetoothError: [Errno 14] Bad address

[Zackariyya]

• OS: Fedora 41
• Python version: Python 3.13.0
• NXT-Python version:3.3.0
• Connection method: Bluetooth

Traceback (most recent call last):
  File "<string>", line 3, in send
_bluetooth.error: (14, 'Bad address')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/mnt/DATA/CODING_FILES/MicroControllers/NXT/nxt-car-tkinter__V2.py", line 30, in <module>
    print("Found brick:", b.get_device_info()[0])
                          ~~~~~~~~~~~~~~~~~^^
  File "/home/$USERNAME/.local/lib/python3.13/site-packages/nxt/brick.py", line 1056, in get_device_info
    tgram = self._cmd(tgram)
  File "/home/$USERNAME/.local/lib/python3.13/site-packages/nxt/brick.py", line 326, in _cmd
    self._sock.send(tgram.bytes())
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/home/$USERNAME/.local/lib/python3.13/site-packages/nxt/backend/bluetooth.py", line 70, in send
    self._sock.send(data)
    ~~~~~~~~~~~~~~~^^^^^^
  File "<string>", line 5, in send
bluetooth.btcommon.BluetoothError: [Errno 14] Bad address

[schodet]

Do you have more details?

What’s your program? What parameters did you use? Does bluetoothctl manage to see the brick?

Can you run nxt_test --log-level=debug?

[Zackariyya]

This is my program

#!/usr/bin/python3
import nxt.locator
import tkinter as tk


def onKeyPress(event):
    e = event.char
    if e == 'w':
        print("Forward")
        wheel1.run(-100)
        wheel2.run(-100)

    if e == 'd':
        print("Left")
        steering.turn(25,60)
    if e == 's':
        print("Back")
        wheel1.run(100)
        wheel2.run(100)
    if e == 'a':
        print("Right")
        steering.turn(-25,60)
    if e == 'q':
        print("Stop Motor")
        wheel1.brake()
        wheel2.brake()

def onKeyRelease(event):
    print("Released "+event)
    e = event.char
    if e == 'w':
        print("STOP Forward")
        wheel1.brake()
        wheel1.brake()

    if e == 'd':
        print("UNDO Left")
        steering.turn(-25,60)
    if e == 's':
        print("STOP Back")
        wheel1.brake()
        wheel1.brake()
    if e == 'a':
        print("UNDO Right")
        steering.turn(25,60)
    if e == 'q':
        print("Release Motor")
        wheel1.coast()
        wheel2.coast()
# Find a brick.
with nxt.locator.find() as b:
    # Once found, print its name.
    print("Found brick:", b.get_device_info()[0])
    # And play a recognizable note.
    b.play_tone(440, 250)
    
    # Get the motor connected to the port A.
    steering = b.get_motor(nxt.motor.Port.A)
    wheel1 = b.get_motor(nxt.motor.Port.B)
    wheel2 = b.get_motor(nxt.motor.Port.C)
    # Full circle in one direction.
    steering.turn(25, 60)
    steering.turn(-25, 60)  
    
    root = tk.Tk()
    root.geometry('300x200')
    text = tk.Label(root, text="Focus this window and use WASD to control NXT")
    text.pack()
    root.bind('<KeyPress>', onKeyPress)
    root.bind('<KeyRelease>', onKeyRelease)
    root.mainloop()
    steering.idle()
    wheel.idle()

bluetoothctl connects to brick, then after a few seconds it disconnects :

USERNAME:~/ $ bluetoothctl                                                                                                                                                                                   [11:38:31]
[bluetooth]# Agent registered
[NXTI]# [CHG] Device 00:12:34:56:78:AB Connected: yes
[NXT]# [CHG] Device 00:12:34:56:78:AB ServicesResolved: yes
[NXT]# [CHG] Device 00:12:34:56:78:AB ServicesResolved: no
[bluetooth]# [CHG] Device 00:12:34:56:78:AB Connected: no
[bluetooth]# 

output of nxt_test --log-level=debug :

Find brick...
DEBUG:nxt.locator:configuration files=['.nxt-python.conf', '/home/USERNAME/.nxt-python.conf']
DEBUG:nxt.locator:configuration read from []
DEBUG:nxt.locator:no section default, using DEFAULT
INFO:nxt.locator:using backend from nxt.backend.usb
INFO:nxt.locator:using backend from nxt.backend.bluetooth
INFO:nxt.backend.bluetooth:connecting via Bluetooth (00:12:34:56:78:AB)
DEBUG:nxt.locator:found brick <nxt.brick.Brick object at 0x7ff067aef8c0>
DEBUG:nxt.backend.bluetooth:send: 0200019b
INFO:nxt.backend.bluetooth:closing Bluetooth (00:12:34:56:78:AB) connection
Traceback (most recent call last):
  File "<string>", line 3, in send
_bluetooth.error: (14, 'Bad address')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/USERNAME/.local/bin/nxt_test", line 26, in <module>
    name, host, signal_strengths, user_flash = b.get_device_info()
                                               ~~~~~~~~~~~~~~~~~^^
  File "/home/USERNAME/.local/lib/python3.13/site-packages/nxt/brick.py", line 1056, in get_device_info
    tgram = self._cmd(tgram)
  File "/home/zackariyyasattaur/.local/lib/python3.13/site-packages/nxt/brick.py", line 326, in _cmd
    self._sock.send(tgram.bytes())
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/home/USERNAME/.local/lib/python3.13/site-packages/nxt/backend/bluetooth.py", line 70, in send
    self._sock.send(data)
    ~~~~~~~~~~~~~~~^^^^^^
  File "<string>", line 5, in send
bluetooth.btcommon.BluetoothError: [Errno 14] Bad address

While that is running, bluetoothctl reports that it connects, then immediatly disconnects:

[NXT]# [CHG] Device 00:12:34:56:78:AB Connected: yes
[bluetooth]# [CHG] Device 00:12:34:56:78:AB Connected: no

NOTE: Those are not the real MAC addresses, I replaced them with that random one.

[schodet]

Does your address starts with 00:16:53?

Make sure there is no NXT-Python program still running in the background (reboot if not sure).

Here is what I do to make it work:

% bluetoothctl
Agent registered
[bluetooth]# devices
[bluetooth]# scan on
Discovery started
[NEW] Device 00:16:53:AA:BB:CC 00-16-53-AA-BB-CC
[CHG] Device 00:16:53:AA:BB:CC LegacyPairing: no
[CHG] Device 00:16:53:AA:BB:CC Name: NXT1
[CHG] Device 00:16:53:AA:BB:CC Alias: NXT1
[CHG] Device 00:16:53:AA:BB:CC LegacyPairing: yes
[bluetooth]# pair 00:16:53:AA:BB:CC
Attempting to pair with 00:16:53:AA:BB:CC
Request PIN code
(here, enter code 1234 on NXT screen)
[agent] Enter PIN code: 1234
[CHG] Device 00:16:53:AA:BB:CC Connected: yes
[CHG] Device 00:16:53:AA:BB:CC UUIDs: 00001101-0000-1000-8000-00805f9b34fb
[CHG] Device 00:16:53:AA:BB:CC ServicesResolved: yes
[CHG] Device 00:16:53:AA:BB:CC Paired: yes
Pairing successful
[CHG] Device 00:16:53:AA:BB:CC ServicesResolved: no
[CHG] Device 00:16:53:AA:BB:CC Connected: no
[bluetooth]# scan off
Discovery stopped
[bluetooth]# devices
Device 00:16:53:AA:BB:CC NXT1
[bluetooth]#

Now I can run a nxt-python script using the 00:16:53:AA:BB:CC address.

If I keep bluetoothctl open, during the script run, I can see:

[CHG] Device 00:16:53:AA:BB:CC Connected: yes
[CHG] Device 00:16:53:AA:BB:CC Connected: no

So this part is normal.

If it does not work, try to remove the NXT from known devices and start again.