I have the D5100. Regardless, no matter what I do it just doesn't work. It now fires 30sec or less. It crashed on me like 5 times though

No more idea? I guess it's Windows then...

Give it a little more time friend, Rome wasn't built in a day. I tried to help and I don't even have a DSLR. There is probably someone here who has already invented your wheel and has a solution. They just haven't seen the thread, maybe El Corazon will get back to you.

You gotta admit you did have success, maybe not what you wanted but you got connected. Also post your logs.

The D5100 can be directly controlled via USB and the Nikon DSLR driver in the Device Manager.

You do NOT need DSUSB.

It really is a full fledged astrophotography camera. Put it in Bulb mode and you can expose ad infinitum.
Look at the manual for your camera. I assume the sockets are arranged the same way as for the D3300. In that case, open the lower compartment on the left side of the camera and plug the USB cable into the upper one of the two sockets.
You have to check the user manual to find out what that cable is called for the D5100. Different Nikon cameras have different sockets. For instance, I have the D600 and the D3300. Both require different USB cables, but the control through Ekos is the same and it works like a charm.
DSUSB is just a dumb shutter release. It sends acoustical impulses via the 3.5mm jack to the camera which tell it to open or close the shutter. If you are going that route, then Ekos cannot possibly perform, since no images will reach the Pi4 (or any other computer for that matter).
Controlling the camera directly is the way to go, but if you don't have that USB cable, then you have to get it first. We are here to help, just get back to us when you are ready.

Best wishes,

Jo

PS: You need the cable that goes into Port 29 on the attached schematics for the D3300. Your DSUSB connects to Port 27, I believe.

El Corazon, you are partly right. I agree, the DSUSB is really just a dummy shutter. All it does that it shorts three cables and holds it for the desired seconds, thus long exposure.
But, the D5100 is not a full fledged astro camera. I utilizes two USB cables to achieve anything over 30 seconds exposure. 30s or less only requires the main USB cable, no DSUSB needed. This is the cable that is used to download the image to the PC/Pi 4. As I could do 30s< exposures even if I picked the native Nikon driver in INDI, it always downloads the image to Pi 4 via this cable.
Exposures over 30 however is a different question. I have the DSUSB control box and built myself a USB shutter control that is based on FTDI chipset from CN forum. They both work under windows and do the same thing. Short three cables for the desired time and use the main cable to download the image. I have never had to use memory card in the camera for this too.
So, in summary, the D5100 does need the help of an extra long exposure cable. If you go to any capture software website, they have this detail in their camera compatibility matrix.

OK, I am not sure about the D5100, that is an older model. Can you control it using the USB cable only or do you need DSUSB for shutter release?

Regardless, one of my buddies in the local astrophotography club here has a very old Canon which he controlled using Indi and Ekos exactly the same way you are trying to do now using DSUSB for shutter control while downloading images via USB and he has no trouble getting 120s exposures out of it.

So I know it is possible.

I would not give up on Ekos, it is fantastic. I am on it right now, got to schedule some jobs. Will be back after it starts exposing for more discussions.

Jo

Since you have a serial device, set the port to the actual serial port, and not DSUSB. For example, try "/dev/ttyUSB0" (without quotes, but with the slashes, and case matters, and that's a zero at the end, not the letter o)

Setting it to DSUSB invokes entirely different code, meant for a different device.

BTW, that "/dev/ttyUSB0" is just the Linux way of naming serial ports. If you have more than one (for example, a serial connection to your mount) the next port would be /dev/ttyUSB1. Windows would call it COM1 or COM2 or something. And if you do have more than one /dev/ttyUSBx, try them all You can use the file explorer, and go to the /dev folder to see what devices are there that begin with ttyUSB

Thanks kross I had no idea that's how Linux sees COM ports. However, I have tried that yesterday without any success. Would the /dev/ttyUSB0 need to be set under Gphoto camera or under Nikon camera driver?

I use DSUSB with a Canon camera, so this may be different but in the Canon DSLR settings I set the Shutter Release Port to be DSUSB. But maybe the Nikon driver is different.

Here is a screenshot.

This is using astroberry also.

DSUSB is for the devices sold by Shoestring Astronomy. But I think Moxican said he's using a home brew device based on an FTDI chip, which is entirely different than DSUSB devices. The FTDI (serial port) devices just use the RTS line of the serial port to control the shutter. The driver just needs to know which port (tty device) to use. I looked through the source code for the driver, and if you set a serial port in that field, it toggles the RTS line for shutter control. If you set DSUSB in that field, it invokes entirely different code that talks to special USB device (the kind made by Shoestring Astronomy).

I think (but not sure) that it will work with Nikon and GPhoto drivers, but try both. Also, check to see if you have more than one /dev/ttyUSB device. Just like in Windows, you might have more than one COM port.

I will check that out.
A side note, I have both DSUSB and FTDI chip for the camera in subject.

I would suggest getting in touch with astronate (previous comment). He has it going with his Canon and DSUSB. So if you have the DSUSB device from Shoestring Astronomy I would just copy his settings.