Hello Everyone, I have implemented FS USB on STM32F303RE nucle board. But I detach the programmer and want to use the STM as a stand lone,Then the usb is not working, I

[Patukes]

..

[Patukes]

This my error message

This is my error:

[TDK]

As a quick check/fix, perhaps add a 250ms delay at startup before initialization of USB.

[Garnett.Robert]

Hi,

I don't know if this is relevant to your problem

I have a project which would run under debug, but crash on power recycle.

I used a GPIO driving my scope and found the program when running stand alone had a hard fault: unknown instruction.

Difficult to debug because the fault only occurred running stand alone.

By placing the GPIO write in different locations I found the problem code and fixed it. (Stackitis).

I don't know why it worked under debug, but no stand alone.

Hope this helps

Best Regards

Rob

[Patukes]

Thank you everyone one for the answers you provided. The major problem was that the micro-controller started with the internal RC oscillator(clock) ; this can't work with USB as USB requires a more stable clock. So I used an external clock.