ROV Locator Installation on a BlueROV2

I had the opportunity to get back to work on a project to refitting my BlueROV2 with some new technology.

One of those is the ROV Locator. I’ve been looking forward to a USBL system for quick, small boat deployments for archaeological work. I haven’t seen an installation thread yet for the ROVL, so I thought I would post my progress and design choices for a topside box to make everything nice and neat.

Let's start with what comes in the box.

1) ROV Locator USBL Receiver
2) ROV Locator Beacon
3) ROV Mounting Bracket
4) Postcard with support materials link


Installing the ROV Locator Beacon

Because I’ll be doing a standard configuration, the first step is to potting the cable for the transmitter. First, we’ll strip away a few inches of the cable jacket.

Next, we’ll pot the cable. I used an M10 penetrator for a 3mm cable.

While I was waiting for the epoxy to cure, I worked on drilling the holes for the mount.

Test fitting to check the height. I wanted the transmitter a bit lower than the very top of the frame, so it is out of the way of the Ping360 I plan to mount on the other side. The transmitter will still show in the Ping360 acoustic image, but it should be less than if it was up high.

After the penetrator was cured, I crimped on male header pins onto the negative and positive wires.

The penetrator was installed onto the endcap.

And the wires were pulled free to be accessible.

I connected the power wires to a 5V6A Power Supply. The RX and TX wires are unconnected and not needed for this installation type.

Secured the transmitter to the mount and tucked away from the excess cable.

Success! ROV Locator Beacon installation completed


Installing the ROV Locator USBL Receiver

The topside box is going to take a bit more work, but not much.
The Receiver will easily connect to a topside computer with a BLUART Serial to USB converter. With the understanding that it would be easy to make a connectorized waterproof box.

However, we already have a box with the FXTI, and that has a USB connection already. So my plan going forward is to put a USB hub inside the FXTI and connect everything through that.

After some research, I had picked out a USB hub from Adafruit that was thin enough to fit inside an FXTI. Unfortunately, due to the pandemic, the lead time from DigiKey is around 60 days. I won’t see that one for a while.

So with that, I decided to proceed anyway and have another USB cable out of the FXTI.

I wired both the Binder 770 plug and bulkhead according to the pinout from the Blue Robotics Connector Standard for serial devices.

I fit the bulkhead connector into a spare port on the FXTI, and connected the BLUART and USB cable.

Everything was then put back together.

UPDATE

Cerulean has a new serial to USB cable intended for use in an ROVL system with the ROVL Rx (receiver) on the top side, plugged into either a laptop or the Cerulean BlueROV plug-and-play integration module – but it can be used anywhere serial-to-USB conversion is required

Success!

I plugged in the USB cable for the ROVL, selected the proper COM port, and everything connected right away. I know it looks like a lot of red, but the bottom left green icon shows I have a good IMU status on the Receiver.

Now we conduct the crystal calibration.