Describe the Bug
On Windows 11, QMK Toolbox 0.3.4 detects my Caterina bootloader correctly, but flashing fails with AVRDUDE communication errors.
The same keyboard and USB cable flash successfully on macOS.
I also tested the same keyboard directly with AVRDUDE 8.1 from QMK MSYS on the same Windows 11 machine. The direct AVRDUDE test successfully detects the bootloader, identifies the ATmega32U4, writes the firmware, and verifies it.
This appears to be specific to QMK Toolbox's flashing process on Windows rather than a hardware, cable, driver, or bootloader problem.
The device is detected as:
- Caterina
- VID:PID:
2341:0037
- Windows driver:
usbser
- Device:
Microsoft Dispositivo Serial USB
- Bootloader port: COM9
QMK Toolbox detects the device, for example:
Caterina device connected (usbser): Microsoft Dispositivo Serial USB (COM9) (2341:0037:0001) [COM9]
Attempting to flash, please don't remove device
but flashing fails with:
avrdude.exe: ser_drain(): read error: A operação de E/S foi anulada devido a uma saída de thread ou a uma requisição de aplicativo.
avrdude.exe: ser_send(): write error: sorry no info avail
avrdude.exe: ser_recv(): read error: O dispositivo não reconhece o comando.
avrdude.exe: butterfly_recv(): programmer is not responding
...
avrdude.exe: error: buffered memory access not supported. Maybe it isn't
a butterfly/AVR109 but a AVR910 device?
avrdude.exe: initialization failed, rc=-1
System Information
- Operating system: Windows 11
- QMK Toolbox version: 0.3.4
- Keyboard: Corne (crkbd rev1)
- MCU: ATmega32U4
- Bootloader: Caterina
- USB VID:PID:
2341:0037
Additional Context
The failure is reproducible with QMK Toolbox 0.3.4.
No other USB devices were connected during testing.
To isolate the problem, I closed QMK Toolbox and tested AVRDUDE directly from QMK MSYS.
AVRDUDE version:
Avrdude version 8.1-20250625 (b440362)
The following command successfully connected to the bootloader:
/opt/qmk/bin/avrdude -p atmega32u4 -c avr109 -P COM9 -b 57600 -v
Output included:
Programmer id = CATERIN; type = S
Software version = 1.0; no hardware version given
AVR device initialized and ready to accept instructions
Device signature = 1E 95 87 (ATmega32U4)
I then flashed the exact same HEX file successfully with:
/opt/qmk/bin/avrdude -p atmega32u4 -c avr109 -P COM9 -b 57600 -U 'flash:w:<file_path.hex>:i'
Result:
Reading 20722 bytes for flash from input file file.hex
Writing 20722 bytes to flash
Writing | ################################################## | 100% 3.35 s
Reading | ################################################## | 100% 1.81 s
20722 bytes of flash verified
Avrdude done. Thank you.
Therefore, the same Windows 11 machine, USB connection, Caterina bootloader, COM port, ATmega32U4 and firmware can all be flashed successfully using AVRDUDE directly.
QMK Toolbox fails while attempting the same operation.
Describe the Bug
On Windows 11, QMK Toolbox 0.3.4 detects my Caterina bootloader correctly, but flashing fails with AVRDUDE communication errors.
The same keyboard and USB cable flash successfully on macOS.
I also tested the same keyboard directly with AVRDUDE 8.1 from QMK MSYS on the same Windows 11 machine. The direct AVRDUDE test successfully detects the bootloader, identifies the ATmega32U4, writes the firmware, and verifies it.
This appears to be specific to QMK Toolbox's flashing process on Windows rather than a hardware, cable, driver, or bootloader problem.
The device is detected as:
2341:0037usbserMicrosoft Dispositivo Serial USBQMK Toolbox detects the device, for example:
but flashing fails with:
System Information
2341:0037Additional Context
The failure is reproducible with QMK Toolbox 0.3.4.
No other USB devices were connected during testing.
To isolate the problem, I closed QMK Toolbox and tested AVRDUDE directly from QMK MSYS.
AVRDUDE version:
The following command successfully connected to the bootloader:
Output included:
I then flashed the exact same HEX file successfully with:
/opt/qmk/bin/avrdude -p atmega32u4 -c avr109 -P COM9 -b 57600 -U 'flash:w:<file_path.hex>:i'Result:
Therefore, the same Windows 11 machine, USB connection, Caterina bootloader, COM port, ATmega32U4 and firmware can all be flashed successfully using AVRDUDE directly.
QMK Toolbox fails while attempting the same operation.