Distorted video with 3rd party Camera

Third Party Products
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Hey!
Posting this here in hopes of finding the guys with the right knowledge.

We have recently installed a third party camera on our custom ROV. It is meant to be plug and play, but we don’t feel like that’s the case. The camera works well above water. Nothing seems to be bothering it. The problems appear when submerging the ROV under water. If we don’t touch anything the camera works fine, however when we start using a thruster the camera lags out. Can this be because of electronic noise? Is it the PWM from one (or more) of the thruster cables messing with the cameras data? Video below:


I know I said emerged instead of submerged, English is not my mothers tongue

One of the main reasons why I suspect the noise is because noise travels easier in water than air (please correct me if this is wrong). The camera-cable is shielded, but I´m not able to find any guides or instructions as to how to wire the shield(in their docs). I know you can´t vouch for this 3rd party company, but can I assume that the shield is meant to be connected to minus? And do you think this could reduce the effects of surrounding noise and better our video stability?

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Hi @Erlingns95 -
Can you share what camera model you’re using? It looks like it may be a DWE ExploreHD camera? We’ve used that with no issues, and not seen what you’re encountering here… very strange!

Disconnecting the shield from ground may be worth trying. How is the camera connected? If it is a USB camera, are the data lines twisted together as they route through the electronics enclosure?

Acoustic noise does travel better in water due to the density of the medium, however radio frequency is blocked completely by water!

It does seem that your issue is related to the “cleanliness” of the power being supplied to the camera…

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You are correct, it’s a DWE ExploreHD camera.

The camera is connected via JST to their multiplexer. The data lines are twisted thoroughly.

You’ve raised an interesting point here, is the PWM-disturbance defined as RF?

I may have phrased it a bit odd but the shield is not connected to ground. This may sound weird but we purposely did not connect this as no instructions told us to. My question was meant to be somewhere along the lines of;

Do you think making the shield-ground connection could solve our issue?

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Hi @Erlingns95 -
I’m not familiar with their multiplexer - is this essentially a USB hub? Is it possible to connect the camera directly to the USB port on the Raspberry Pi?

The ESCs generate lots of RF noise in the back of the main electronics enclosure - this is likely what is interfering with your video signal, likely on the multiplexer?

Connecting the shield to ground is necessary for the shield to function! Without a ground, any RF intercepted by it has no path to be dissipated. Connecting only one end of it to ground may eliminate your problem - giving the feedback to DWE to update their instructions would be helpful! ( support@dwe.ai)

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I’m not really sure what the multiplexer is defined as, but it communicates with the RPI via usb-c. It has 7 JST-connectors that allow you to easily plug up to 7 extra cameras into your ROV.

The cameras are plugged directly with JST, not JST-USB. I know that some adapters exist, but we don’t have any.

I’ll give it a shot tomorrow and let you know how it goes. Hopefully connecting the shield inside the enclosure will do the trick.

Now I don’t want to slander the guys, that’s why I originally didn’t mention the producer. They’ve made some properly good products! However, they’ve got a thing or two to learn from you guys. We’ve tried reaching out on their forums, and also via the same e-mail you just sent. Now I don’t know if they’re not taking us serious, or just think their time is more valuable other places, but their level of communication is nowhere NEAR yours. We really enjoy how much we can “rely” on a response from you guys. That does unfortunately not seem to be the case currently with DWE.

Their system simply seems to be missing a couple of pieces. For example: On their YouTube channel they´ve made a fairly good guide on the multiplexer, and the ExploreHD cam. They show how they apply a wetlink to the cable, how the cable is connected to the multiplexer, and how the multiplexer is connected to a RPI. However- The wetlink does not come with the camera, and the multiplexer does not come with essential standoffs/ nylon spacers nor screws to make it fit. You should also get an ever so special usb-a to usb-c cable with a 90* turn in the usb-c end. This cable should be quite short, as you don´t want to make a spool inside your enclosure. But how short? Have a guess. The cam-guide never shows a shield, in either end of the cable, nor what to do with it. Neither do the docs.

I can tell you right away that we had none of the parts mentioned above, and found out along the way as we were trying to install our first cam. Now of course it wasn´t impossible for us to get what we needed, but we had to buy some unnecessarily large packs.

My thoughts are; if they were to charge an extra 20 bucks for some screws, standoffs, this strange cable, a fitting wetlink and possibly even a JST-usb adapter, they would make good extra money and people would still buy their products! Probably even more! Even if you don´t add everything to every order, just make it an option when buying? At least let the buyer know what you also need to get, if you’re not able to supply them yourself. Felt like buying half a product.

I´ve mentioned quite a few of these things, and feel like the response is quite cold. Maybe they are listening, just not confirming it to us.

Truly hope they make the buyers experience a bit better, ´cause the products themselves are innovative and smart!

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Hi @Erlingns95 -
I believe the multiplexer is basically a USB hub, but it may have some additional features… How many cameras are you intending to use with the Blue ROV2, and for what kind of application?

You’ll be excited to know I’ve recently been working to get this DWE camera onto our Reef, and address many of the issues you bring up!

The intention is to offer (just) a camera with 1m cable, WetLink Penetrators installed, and using a jst-gh connector (that fits through 10mm hole) to connect to the the Pi USB port via our existing JST-GH to USB connector and coupler PCB that is used with the Ping360. This would cost the same amount as the camera purchased directly from DWE.
We’re verifying that this hardware configuration works as expected, and grappling with some minor issues, but hope to launch this in Q1 next year!

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Very good Tony. This has also crossed our minds, as a business opportunity.

I believe you will do a good job on selling the product as a whole. I´ve got blind faith.

Connecting the shield to minus inside the el-enc. was the solution. Probably obvious to some, but the fact that I didn´t find anything about it in their docs (even though they have a wiring diagram) upset me a bit.

We are not using a BlueROV2, just the “electric skeleton”. The sub itself is homemade in a garage, and its intended use is a bit secret, for now. However we are using a complete BlueROV2 setup including electronic enclosure, 2x 22,2V batteries (+enclosures) and currently 6x T500 thrusters. We haven’t landed on how many cameras we “need”, but adding a second one in a position irrelevant to the el-enc made a huge difference for us. Simply being able to see in multiple directions and/or from different angles makes orientation so much easier. It also seems to be a bit more wide-angle than the original one in the dome.

Can I ask if you guys have the JST connector that DWE uses? We’re preparing an order from you and would like to add a couple of those if you have them in stock. You probably know the correct name for it better than me, is this a JST-GH? Or just a JST? I know what it stands for, but is it a common designation for all of them?

Screenshot 2024-11-04 at 17.05.33
Screenshot 2024-11-04 at 17.05.33602×504 79.7 KB

It is a bit larger than those used on the navigator. Meant for the multiplexer.

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Hi @Erlingns95 -
I’m not sure what connector they’re using there, apologies!
We try to document all of ours on the connector standard, and wish more manufacturers adhered to it to keep things cross-compatible!

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