After soldering the blank PCB, inserting the USB cable triggers an error message.

[mayjack0312]

The exception is as follows:

Unrecognized USB Device
The previous USB device connected to this computer did not function properly, and Windows could not recognize it.
Recommendation
Try reconnecting the device. If Windows still cannot recognize it, the device may not be functioning properly.

[guigur]

Hi!
If you've ordered the parts yourself and soldered all the tiny SMT parts, congratulations!
From the factory the STM32G4 comes with an ST bootloader but it does not support USB (as far as I know)
You need to set the option bytes and upload OwnTech's bootloader using an ST-Link.
Happy programming!

[jalinei]

Actually the ST bootloader does support USB - you can flash the bootloader easily using this option :

Make sure to tie pin 58 to 3.3V and press reset button

[mayjack0312]

Actually the ST bootloader does support USB - you can flash the bootloader easily using this option :

Make sure to tie pin 58 to 3.3V and press reset button

Thanks

[mayjack0312]

Could you please provide specific programming instructions? I've soldered two modules, but programming them both is problematic.

• NRST does not have pull-up resistors. Do I need to add them separately? Does NRST require wiring during programming?

[jalinei]

There are full instructions from the vendor.

https://www.st.com/resource/en/application_note/an3156-how-to-use-usb-dfu-protocol-in-bootloader-on-stm32-mcus-stmicroelectronics.pdf

The summary is what I told you : With the usb connected to your computer, reset the board with BOOT0 pin tied to 3.3V and press reset button.
With a green STM32G474 configured with factory default, it should enumerate as a USB DFU class, allowing you to flash the bootloader as shown before.