Water Linked Underwater GPS / BlueROV2 Integration Kit Documentation



Introduction

The Water Linked Underwater GPS is designed with a generic connection interface so that it can be used in a wide variety of applications, but in its stock configuration, it can be difficult to integrate with the BlueROV2. The Water Linked Underwater GPS / BlueROV2 Integration Kit provides a few components to make a seamless connection between the BlueROV2 system and the Water Linked system.

To install the kit on a Water Linked system, you first add a Fathom-X tether interface board to the box so that it can join the BlueROV2’s network without an Ethernet switch. We also swap the Ethernet bulkhead on the box for an 8-pin connector that provides a single cable connection between the BlueROV2 topside electronics and the box.

The integration kit requires some minor assembly and instructions are below!

Specifications

Specification Table

Item Value  
Cable Length (WL Box to Fathom-X) 8 meters 26 ft

Installation

Included Parts

Quantity Part
1 8 meter cable with Bulgin 8pos (to WL box) to cable penetrator (to BlueROV2 topside)
1 Internal battery cable (XT90 to Molex 3mm connector)
1 Fathom-X power cable (JST-GH to ferrules)
1 Pre-wires bulkhead connector (Bulgin 8pos to JST-GH 3pos and ferrules)
1 Fathom-X Tether Interface Board

Inside WL Box

Inside the Water Linked box, we’ll be adding a Fathom-X tether interface board and a few cables to make integration seamless. This Fathom-X board will be in addition to the Fathom-X board that is already used on the ROV topside. The two boards are connected in parallel to the same twisted pair, putting the ROV, topside computer, and Water Linked box on the same computer network.

Here’s a diagram of what we’ll be connecting inside the box:

  1. Remove the backing from the red 3M VHB tape on the back of the Fathom-X mount.

  2. Install the Fathom-X board in the Water Linked box as shown below.

  3. Unplug the Ethernet cable from the connector on the side of the box, route underneath the Water Linked board, and plug into the Fathom-X module.

  4. Remove the Ethernet bulkhead connector from the side of the box. Remove the protective cap from that connector for reuse with the new connector.

  5. Install the new bulkhead connector into the same hole, making sure the circle on the connector body is facing upwards. Replace the protective cap.

  6. Using a small flathead screwdriver, connect the red and black wires to the positive and negative tether input terminals on the Fathom-X board.

  7. Next, unplug the small A1 plug from the top right corner of the Water Linked board. Plug in the new A1 plug and leave the original one hanging loose.

  8. Plug the Fathom-X power cable into port D5 or D6 on the Water Linked board. Then connect the ferrules on the other ends of those wires to the positive and negative power input on the Fathom-X board (black terminal block).

  9. Add a zip tie to the wiring harness to keep all wires tidy.

Nice job! You’re done with modifications to the Water Linked box. Up next, we’ll show you how to connect the box to your ROV.

To ROV

The connections made near the topside Fathom-X interface and topside computer will connect the ROV, Topside Computer, and Water Linked systems to each other. Here’s a high level diagram of what that will look like:

These connections are made on a terminal block with a few provided wires. Note that this isn’t the nicest solution in the world, and we plan to have a more polished solution in the future. Below is a diagram of how the components are connected together along with step by step connection instructions.

  1. Connect the red and black wires to the topside Fathom-X board. White and blue heatshrink is used to show the functional connection to the other twisted pairs.

  2. Connect the tether blue/white and green/white pairs to the terminal block, matching the existing blue/white and green/white pairs.

  3. Plug the wires from the black Integration Kit cable into the header connectors, matching colors.

Note: We strongly recommend mounting the Fathom-X and terminal block in a protective box or case. The wiring here is fairly fragile and easy to damage. Blue Robotics is working on a much better solution to this that will be available in the future.