[Paparazzi-devel] olimex stm32f405 bootloader strange behaviour

[Chris]

Hi.
I came across a strange problem while experimenting with the olimex 
stm32f405 board.
When nothing is connected to the board everything works fine and the 
dfu-util uploads the code.
As soon as i try to upload the code but with the gps connected 
(obviously powered from the usb +5v)
dfu-util cannot find  the bootloader and more importand the dmesg 
command shows that the usb device cannot be enumerated.
Now either the gps (ublox NEO7) with active antenna and superb 
sensitivity is jamming the usb signals via
the usb power line or something else is happening.
I will try with another gps also but i thought that maybe someone has 
encountered this behaviour also.
The discovery board does not have this problem with the same gps but i 
will test it again just to be sure
as i haven't seen anything like this before (i also changed the gps uart 
in the airframe file and it still does it)
Chris