Cannot connect to app3.0

I cannot make Development Desktop 2.1 connect to app3.0 board.

The board turns up in device manager as a USB device

DD2.1 tries to connect

but then gives up

Iv'e tried to update fw without luck - I only get an error stating "No DFU capable USB device available":

PS C:\COINES\v2.8.8\firmware\app3.0\coines_bridge> .\update_coines_bridge_flash_fw.bat
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2019 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Invalid DFU suffix signature
A valid DFU suffix will be required in a future dfu-util release!!!
No DFU capable USB device available
Press any key to continue . . .

 

The problem is the same no matter if I connect my BMM350 module or not.

What can I be missing?

8 replies