AnsweredAssumed Answered

STM32F105RC DFU troubles

Question asked by urasinov.iurii on May 12, 2012
I have two board on STM32F105RCT6.
Both have same troubles.
I run board in bootloader mode.
I sure that MCU is in boot mode, because my programm doesn't work at this time.
I connect USB cable, windows can not recognize usb device (VID=0, PID=0).
Disconnect cable and connect at second time, again unknown device.
Reconnect at third time all is, windows recognize "STM Device in DFU Mode"
I test two boards with different usb cables, on different PCs with WinXP and Win7.
I test it more than 20 times.
Alway windows recognize only at third connection.
Always first and seconds connections fail. Third, fourth and all other follow-up connections are ok.
I make pauses between connection from 1 sec to 30 seconds, Alwayw third connection is OK.
What happens?
MCU data code is 127.

Outcomes