2012-05-12 02:35 AM
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.