HI
i want to program my board by using usb dfu bootloader with stm32cubeprog . I read STM32 microcontroller system memory boot mode (AN2606) and i design my board with using this application note . power supply of this board is separated and doesn't use VBUS as power supply ,and i use 25MHz crystal , this header board is a education board , and i want to program it while usb connector is always connected to the computer . according to the below picture , i want to enable usb dfu bootloader by powering off my board and changing the boot switch and then powering on my board . i think that by using this method MCU goes to the boot mode , in our case by doing this work while usb connector is connected , some times my board is detected , and usually i see this message in my computer <device is not recognize>
that means my board is not detected . i know that my method or my design has problem but i don't know what is it . do you know what is the problem ?
