We’re installing a DVL A125 into our AUV. Quick summary is I am able to connect to it directly through my laptop and it’s ethernet cable, and it functions as expected. However, the Navigator/Pi can’t see it. Here are some setup specs and things we’ve tried.
Latest DVL stable firmware
24VDC power (actually more like 26.3V)
Cable is spliced through SubConn connector (confirmed functionality through this)
JST-GH connector goes through RJ45 converter board/jack (also confirmed functionality through this)
Ethernet cable plugs into 8-channel switch (unmanaged, MOXA EDS-208)
Pi/Navigator stack also connect to switch via Pi ethernet port
DHCP set for both DVL and BlueOS
As I mentioned before, I can connect to the DVL (in a bucket o’ water) through the entire cable run, using the ethernet cable that usually goes into the switch, and it works. Once I plug that same cable into the switch or the Pi, silence. Even if I connect to the switch (with nothing else plugged in but the DVL) I can’t see it. I’ve set static IPs at 2.200, 2.95, and more, rebooted, and nothing. When I ping through terminal, nothing from all of the addresses. DVL extension looks through the 2, 3, and 194 subnets, doesn’t find anything. I’m probably forgetting some things I’ve tried, but at this point I’m lost. Is the BlueRobotics Ethernet hub required for functionality?
Hi @BrookiePWM -
The Blue Robotics Ethernet switch is definitely not required - just an ethernet switch of some kind!
To confirm - you connect your computer to the same switch the BlueOS Raspberry Pi is using, and you can reach the DVL (at what IP address?)
And then, what version of BlueOS are you using, and has the DHCP server in BlueOS been turned on (with what subnet?) What is the static IP of that Raspberry Pi? Screenshots of BlueOS ethernet IP configuration would be helpful.
Some switches can struggle with ethernet signals that have been passed through non-standard connectors like SubConn…
I’ve left the AUV so I can’t verify OS version, will do first thing tomorrow (US EDT).
To clarify, I can only connect when the DVL is connected directly to my computer through it’s ethernet adapter, not through the switch. The successful connection I am making is through the ethernet cable –> JST adapter –> SubConn connector and cables –> stock cable to the DVL. As soon as I unplug the ethernet from my adapter and plug it into the switch, the network can’t find it. We are going to try another switch tomorrow to see if there’s a change.
I’m not skilled with ethernet protocols, it even looks like I don’t know what a subnet is. I will gather those screenshots tomorrow (though I do know that the DHCP server is on). I’ve tried the DVL with DHCP on and with static IP.
Hi @BrookiePWM -
Here’s a good AI explanation of subnet. I’m basically asking if you’ve change from the default 192.168.2.2 IP address for BlueOS and the general network?
A subnet (short for subnetwork) is just a way of carving a big neighborhood into smaller ones. Here’s the analogy:
Imagine a city (the internet) made up of many neighborhoods (networks). A subnet is like drawing new boundary lines to say: “These 10 houses are their own little community, and these other 20 houses are a separate one.”
Why does this matter?
Devices in the same subnet can talk to each other directly, like neighbors shouting across the fence.
Devices in different subnets have to go through a router — like sending a letter through the post office.
Subnets keep traffic organized, improve security, and prevent chaos on large networks.
The subnet mask is just the rule that defines where the “neighborhood” ends and the “house number” begins. When you see something like 192.168.1.0/24, the /24 means: “the first 24 bits are the neighborhood, the rest are the individual houses.” A /24 gives you 256 possible addresses (254 usable), while a /16 gives you a much bigger neighborhood with 65,000+ addresses.
Update: I’ve been able to get it working! Tony - thanks so much for your help. It turns out the problem was the wiring. I had it wired through a standard SubConn 8-pin (MCIL8) without twisted wires (only a short length of un-twisted, about 30cm either side of the SubConn). While my computer was ok decoding the signal, the switch and the Pi were not. After confirming with testing, I’ve re-spliced through a SubConn Data series (DBH8F → DIL8M) and it’s working just fine. Keep your wires twisted folks!