"Built in DFU firmware"... Not working?

[devinw]

It is my understanding from watching this video from ST:

https://www.youtube.com/watch?v=Kx7yWVi8kbU

That many STM32 chips come with a built in bootloader in ROM that can be accessed by pulling the BOOT0 pin high.

However, I just took a couple of brand new STM32 blue pills out of the package and was not able to see the USB device enumerated, and when I opened STM32 Cube Programmer and select USB, it sees nothing and says "NO DFU DEVICE FOUND"

The blue pills are a super basic board and have jumpers to pull BOOT0 and BOOT1 high, so I would think this would work. ST Application Note AN3156 says that the STM32 chip on this board support the DFU built in bootloader, so I'm not sure what's going on here. Anyone have any light to shed on this?

[AScha.3]

Hmm...the DFU bootloader was on UART (and is) at first, the USB or CAN etc. came later on newer, more powerful chips.

So if you use the first and oldest ARM / STM32 ever, dont expect same functions as on a 10 years more recent chip series.

In AN3156 is :

...as i wrote:

[devinw]

Ah... thanks for that information. I missed that.

BTW, I just received my board for the proejct I'm working on with STM32G431RB and the USB DFU works perfectly. Enumerates and flashes with Cube Programmer on macOSx. :)