AnsweredAssumed Answered

STM32F7 USB device not being detected

Question asked by chris250 on May 25, 2016
Latest reply on May 25, 2016 by FTITI.Walid
Hi All,

I'm using a STM32F7 Discovery board. I am using the example application (unmodified) from Cube for being a USB MSC device.

When I run the code with the debugger connected (using ST Link) everything works as expected - the device is detected and enumerated by Windows. I can read/write files to the STM32-based mass storage device through the HS-USB port on the board.

To demo the project without the debugger running, I disconnected the ST Link cable and changed the power supply jumper to the usb_hs position. I now find that the detection of the device is intermittent. When it is detected by Windows on insertion, everything works fine. Other times Windows does not detect the device at all.

I guess the intermittent performance is either a race condition or a physical layer issue.

I have checked the HAL and there is a timeout to allow the external ULPI PHY to boot (T start in the 3320 datasheet).

Does anyone have any experience in reliably using the STM32F7 discovery board as a High Speed USB device? Any ideas?

Thanks in advance.