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usb.core.find() fails

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Valutazione

Difficoltà
4/5
Tempo stimato
3-5 giorni
Idoneità per principianti
55/100
Tipo di issue
Bug
Chiarezza
Abbastanza chiara
Stato di attività
Attiva
Stack tecnologico
c, python
Ambito
embedded-iot

Direzione di ricerca

Start with the usb.core.find(find_all=True) call in the reproduction and compare its behavior on the listed working and failing CircuitPython builds for the Feather RP2040 USB Host. The issue also points to examples/usb_host_midi_simpletest_rp2040usbfeather.py as related context. Done means the call returns attached devices on the failing builds, including the SanDisk drive and other USB devices mentioned.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

bug usb
CircuitPython version and board name
Adafruit CircuitPython 10.3.0-alpha.3-22-gdb82b25b4d on 2026-07-10; Adafruit Feather RP2040 USB Host with rp2040
Code/REPL
# List all attached USB devices (probably only one).
# For "Adafruit Feather RP2040 with USB Type A Host" device.
# Based (loosely) on examples/usb_host_midi_simpletest_rp2040usbfeather.py

import usb.core
import time


print("Looking for all USB devices...")

while True:
    devices = usb.core.find(find_all=True)
    if devices is None:
        print("No devices")
    else:
        n = 0
        print(f"Iterating on {devices=}....")
        for device in devices:
            n += 1
            print(f"\t#{n}: {device=}")
            try:
                print(f"\t**** Found vendor:product {hex(device.idVendor)}:{hex(device.idProduct)}")
            except Exception as e:
                print(e)
                continue
    print("  Sleeping...")
    time.sleep(1)
Behavior

**** Typical successful output:

soft reboot
code.py output:
Looking for all USB devices...
Iterating on devices=<USBDevices>....
        #1: device=<Device>
        **** Found vendor:product 0x781:0x5581
  Sleeping...
Iterating on devices=<USBDevices>....
        #1: device=<Device>
        **** Found vendor:product 0x781:0x5581
  Sleeping...
Traceback (most recent call last):
  File "code.py", line 9, in <module>
  File "usb_host_lsusb.py", line 27, in <module>
KeyboardInterrupt: 

Code done running.
Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.

Press any key to enter the REPL. Use CTRL-D to reload.

Adafruit CircuitPython 10.3.0-alpha.3-13-gbaa3ca8650 on 2026-07-07; Adafruit Feather RP2040 USB Host with rp2040
>>>

**** Typical failure output:

soft reboot
code.py output:
Looking for all USB devices...
Iterating on devices=<USBDevices>....
  Sleeping...
Iterating on devices=<USBDevices>....
  Sleeping...
Iterating on devices=<USBDevices>....
  Sleeping...
Traceback (most recent call last):
  File "code.py", line 9, in <module>
  File "usb_host_lsusb.py", line 27, in <module>
KeyboardInterrupt: 

Code done running.
Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.

Press any key to enter the REPL. Use CTRL-D to reload.

Adafruit CircuitPython 10.3.0-alpha.3-22-gdb82b25b4d on 2026-07-10; Adafruit Feather RP2040 USB Host with rp2040
>>>
Description

Problem: usb.core.find(find_all=True) returns an empty generator even when something's plugged into the USB A port.

Additional information

This code stopped working with build

CircuitPython 10.3.0-alpha.3-22-gdb82b25b4d on 2026-07-10 (adafruit-circuitpython-adafruit_feather_rp2040_usb_host-en_US-20260710-main-PR11093-db82b25.uf2)

which was supposed to address a previously-reported issue with some MIDI keyboards. Now the issue happens with all USB devices (a SanDisk USB stick was used for testing, as well as other USB devices).

**** Fails on these builds (the one purporting to fix it, as well as the latest build available):

Adafruit CircuitPython 10.3.0-alpha.3-22-gdb82b25b4d on 2026-07-10; Adafruit Feather RP2040 USB Host with rp2040
Adafruit CircuitPython 10.3.0-alpha.3-25-g242fe31782 on 2026-07-13; Adafruit Feather RP2040 USB Host with rp2040

**** Succeeds on these builds (the one before the purported fix, and the latest alpha):

Adafruit CircuitPython 10.3.0-alpha.3 on 2026-06-24; Adafruit Feather RP2040 USB Host with rp2040
Adafruit CircuitPython 10.3.0-alpha.3-13-gbaa3ca8650 on 2026-07-07; Adafruit Feather RP2040 USB Host with rp2040

Lingua principale
C
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Fork
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