Slim, tough USB cable for external Low-Light USB Camera?

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I’m adding the Blue Robotics low light USB camera as an external camera to an existing ROV where it’s not straightforward to install it internally. I printed an adapter to mount it in an aftermarket dive housing for a GoPro Hero 5 Session:

br_divecam_1
br_divecam_14032×3024 2.93 MB

I’m using a drilled-out 1/4"-20 sealing screw from McMaster Carr (#90825A840) as a tiny cable penetrator into the camera case, with a cut-down threaded insert (#92395A116) as a nut:

br_divecam_2
br_divecam_24032×3024 2.88 MB

It all works fine, I’ve tested it so far to 35m equivalent pressure (it’s rated to 45m) for half an hour with no leaks. Unfortunately, I’ve already accidentally nicked the jacket on this cable (fixed with liquid electrical tape before the pressure test), and I also worry a little about this jacket developing cracks over time from flexing. I think this will work okay if I treat it gingerly, but it’d be nice if I didn’t have to.

I need something that’s around 1/8" diameter or less if I want to keep using the sealing screws. Anyone have any suggestions for a particularly tough small-diameter USB cable for submersible applications? The harsh-environment, continuous-flex USB cables I’ve found would all require a significantly bigger penetrator, and I’d probably have to start going through the side wall of the case. (The backwards-pointing cable is convenient in my application).

By the way, if anyone’s interested in building one of these, the case I’m using so far is this FitStill Dive Housing Case for GoPro Hero 5 Session and I’ll upload the camera mounting bracket to Thingiverse.

I’ll also put another adapter on Thingiverse for this Impact Imagery housing, which has an actual glass front plate. I haven’t pressure tested that one yet, but it gets good reviews.

I’m a new user at Thingiverse so those links won’t go live until tomorrow when I can publish the things.

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Is your ROV receiving the USB signal through a Rasperry Pi?

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Yes, it is. This camera plugs into a Raspberry Pi 3 Model B housed in the ROV’s main electronics enclosure. I use gstreamer (gst-launch-1.0) to stream video and use MAVLink for remote control over the Fathom X tether system. Topside, I use QGroundControl.

On an older version of Raspbian, I used the companion computer setup script to get gstreamer working:

Here’s a thread that started when I was getting it working the first time:

I think that recent versions of Linux on the RPi might just work with gst-launch-1.0 binaries installed using apt, and you probably don’t have to build from source, but I’m not sure.

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check out Using Blue Robotics Low LIght USB cameras in ROV system