With the earlier Nikon cameras like my D5100 the exposures are limited to 30s with gphoto2. The DSUSB allows separate shutter control for longer exposures. I can take exposures over 30s with my wife's D750 but not the D5100. Even in windows the DSUSB was necessary for long exposures with the D5100.
I've attached a photo. The light colored cable is part of DSUSB and plugs into a usb port. There is a separate shutter release cable that connects DSUSB to camera. Also a data transfer cable is needed for gphoto2. Without DSUSB only 30s exposures can be taken with D5100.
Ok I committed preliminary support for DSUSB, please test tomorrow. When you connect, put DSUSB in the port and try. There is a good chance nothing would work, so have TeamViewer ready as well.
Nope, it's waiting for someone to test it. You must enable DEBUG LOGGING to a file (see my signature) _before_ you connect. Whether it works or not, send the INDI driver log.
I have the same problem with my Nikon and DSUSB... My shutter is limited to 30 secs and Ekos doesn't recognize the Shoestring device... Is there any update in that direction? Thanks for your effort in the name of all DSUSB users...
Edit: attached logs.