Need help with Ethernet connection in underwater ROV

[Blue_Alien]

I am working on an underwater camera that uses a Raspberry Pi. The Raspberry Pi is enclosed in a waterproof tube which uses a bulkhead to get power and data into it. Inside the pod, I have an RJ45 plug using only pins 1, 2, 3, and 6 wired as a straight-through. When I connect my desktop through the special cable, it works. But when I connect it to the raspberry pi it does not work. Connecting the pi directly to the router with a regular cable works. Does anyone know how I can remedy this?

[FLYFISH TECHNOLOGIES]

Hi,

Does anyone know how I can remedy this?

This special cable is obviously quite special...
Could you describe how it is made ?


Best wishes, Ivan Zilic.

[Blue_Alien]

The cable is a waterproof, 20 conductor, and about 150ft long. It works with my desktop but not with the pi. Maybe the signal is too low for the pi to handle? Maybe adding a signal booster will allow the pi to connect.

[abishur]

Couple of questions:

1) Which distro are you using?
2) If you connect to the pi in question with a regular Ethernet cable does it work?
3) Do you connect the cable and then power on, or is the Pi already powered on and not receiving an address after the fact (or is it configured as a static IP)?

[FLYFISH TECHNOLOGIES]

Hi,

The cable is a waterproof, 20 conductor, and about 150ft long. It works with my desktop but not with the pi. Maybe the signal is too low for the pi to handle? Maybe adding a signal booster will allow the pi to connect.

You desktop and RasPis have slightly different magnetics (Ethernet connector), so some combinations work where the mentioned falls out of accepted ranges. Adding a signal booster might help, but not necessarily because of the signal boosting.

I don't think that you can get exact answer in the forum(s), from miles away... we can only guess. If you'd like to get proper answer (to be sure that the communication would also work reliably on the field), a network cabling/signals analyzer would help. It could point to the source of the problem and you'd also be able to verify that a modification afterwards shifts states deeply into area aligned with specifications.


Best wishes, Ivan Zilic.

[rpdom]

Is this cable something you made up yourself?

Has it got the correct twisted pair set up?