STM32F405 not recognized by PC (Windows) on USB plugging

afrigerio91 · ‎2016-02-22

Posted on February 22, 2016 at 17:00

I am trying to use my custom board with a STM32F405 chip.

I am powering the board with the USB voltage, with an LDO that brings it down to 2.8V, and programming it through ST-Link using a Discovery board.

I have set up my program using STM32cubeMX including the USB library.

The USB pins are connected to PA12 and PA11 and I have checked their electrical connection.

I have generated the software with cube, and loaded it with ST-Link (IAR). The problem is the device is not detected at all by my computer (it does not show up in the Device Manager) and the USB initialization fails.

I can't figure out where to start, since all I can find on the forums is about not recognized devices, with problems concerning clock speed settings.

Do you have any advice in how to fix this problem?

#usb #stm32cube

Tesla DeLorean · ‎2016-02-22

Posted on February 22, 2016 at 19:01

And you don't have a problem with your clocks, and their settings in the application?

Start with some of the SPL examples, try strapping BOOT0 high and confirm if DFU mode works.

If it's not software you need to review the schematic with more rigour.

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re.wolff9 · ‎2016-02-23

Posted on February 23, 2016 at 09:15

I had to debug a similar problem yesterday. One of the things I did was follow clive's advice and test DFU mode.

In my case, what I should have done earlier is to check the connections from USB to the chip with a multimeter. I had a short in the soldering. (under the USB connector out of view).

I would think that if you have a CLOCK problem, then Linux would report: ''new full speed device detected ... failing to assign ... ''. The detection of ''there is a new device'' happens on just the 1.5k pullup resistor, nothing more. (I don't know how this shows up under windows).

IIRC the '405 needs an external crystal. Is the crystal working?

rwmao · ‎2016-02-23

Posted on February 24, 2016 at 06:12

Maybe it is because of lack of 1.5k resistor.

You can read through the note I wrote, which may help you a little bit.

https://bitbucket.org/rwmao/cdc_onstm32f411rc/raw/12de104e5bb561881af2c471d97ab3d46b30f6b4/Data%20exchange%20between%20STM32F411%20and%20PC%20using%20USB.pdf

afrigerio91 · ‎2016-02-24

Posted on February 24, 2016 at 16:53

I have checked all the circuit connections with a multimeter and they seem to be fine.

I had checked the STM32F405 documents and there is already a 1.5k pull-up resistor on PA12 pin, where I have connected the Data+ line.

Today I have tried to change the LDO in order to have 3.3V instead of 2.8V, but the results are the same.

I also have tried to connect my board to a Linux system and it does not get detected too.

edit: SOLVED

Checking again and again I have finnally found out that D+ line was not correctly soldered to the USB connector pin.

Thank you all for your answers