I'm running Astroberry with a home made shutter release. I can open the terminal window on the Pi and enter the following command dmesg | grep USB | tail -1 This returns the last line from the system log that contains USB. For me it returns FTDI USB Serial Device converter now attached to ttyUSB0 run it before and after plugging in your shutter release so you ensure the device will be the last USB device in the log. Mike Read More...