I tried to replicate the usb part of NUCLEO-F439ZI dev board to a project, without success.

FabioVasconcelos · ‎2023-01-24

I'm using vbus to power supply the MCU, through a voltage regulator.

For the MCU I'm using the stm32f427, not the 39, as in the development board, but they seemed compatible with my project features.

When I connect the board to my laptop via USB, the overcurrent led turns on, and my operating system (ubuntu) does not detect any new USB device.

If I connect boot0 to VCC, the command lsusb in ubuntu takes some seconds to respond.

Can you please give me some suggestions?

Thank you in advance

MM..1 · ‎2023-01-24

Your J21 usb con is faultly connected, too USB data lines need wire as diferential pair on pcb.

FabioVasconcelos · ‎2023-01-25

Hello @MM..1,

What do you mean by a faulty connection?

The data lines are differential, and according to kicad calculator they have ~100Ω (Hope is it not the cause).

I also have 5V in my voltage regulator, so it seems that the power lines are correct, then are connected according with the table below:

MM..1 · ‎2023-01-25

GND pin is open

FabioVasconcelos · ‎2023-01-25

ah okok, sorry, I got what you mean, I hide de ground plane to not have too much entropy in the images. The GND is connected to the ground plane, so it seems that all the connections are ok right? Thanks!

MM..1 · ‎2023-01-25

Then check if con is right orientation plus if you plan connect into PC you act as device and power switch IC3 need off or unsloder.

FabioVasconcelos · ‎2023-01-25

I figure that the overcurrent led turns on because of boot0 is connected to 3.3V, when I change boot0 to gnd, the led turns off. I will need it later, but for now, I will not take that for the equation.

I desolder the IC3 because you are right I will not need it, thank you. But stills not working, the PC does not detect the board.

Another thing that I realize is that programming by jtag through stlink v3, if I supply the board via USB, everything works fine and I flash the board without a problem, using an external 5V power supply, it's not programming. VUSB and external power supply go directly to a voltage regulator ( 5->3.3V) to supply everything. The only thing that changes is PA9 pin, which receives VUSB.

FabioVasconcelos · ‎2023-01-25

I figure that the overcurrent led turns on because of boot0 is connected to 3.3V, when I change boot0 to gnd, the led turns off. I will need it later, but for now, I will not take that for the equation.

I desolder the IC3 because you are right I will not need it, thank you. But stills not working, the PC does not detect the board.

Another thing that I realize is that programming by jtag through stlink v3, if I supply the board via USB, everything works fine and I flash the board without a problem, using an external 5V power supply, it's not programming. VUSB and external power supply go directly to a voltage regulator ( 5->3.3V) to supply everything. The only thing that changes is PA9 pin, which receives VUSB.

MM..1 · ‎2023-01-25

Your board need firmware loaded for detect on PC. Isnt based on you pin connection.

And for use DFU detection is defined in AN2606 plus

FabioVasconcelos · ‎2023-01-31

Hello @MM..1

I have PA11 and PA12 correctly connected, I hope but dfu is not working.

Maybe the first line means something? USB OTG FS configured in forced device. What does this mean?

My boot0 connection:

I really apreciate your effort. Thank you!