My "MINIRAY" Rov.

[asesorplaza1]

Buenas tardes.

Me alegro que a usted le funcione el invento del interruptor de láminas.

Un saludo


Good afternoon.

I'm glad you have the invention of the foil switch work.

A greeting

[Oddmar]

Well Oddmar. your reed switch suggestion works great.

Holy Carp! Someone actually took my advice for once!

I'll call Guinness Book of World Records...

[bigbadbob]

[bigbadbob]

I've not been doing much ROVing lately but last time out it performed fairly well, tether drag is still a slight problem when turning
even with the videoray umbilical but it's usable, and because I'd tweaked the white balance in my camera settings too far the video colour was way off.
before today I had to take my front acrylic dome off the rov to get at the camera settings buttons so it was a right PITA.
But... today I found this neat box of tricks in the scrap bin at work-




it sends camera commands down the coax cable (and twisted pair) and lets me access the settings menu from the top side and set auto or manual white balance settings on the fly.
It runs off 4 AA batteries or 12v and is about the size of my hand so is perfect for use in the field.
yipee, I'm a happy ROVer today.

I was also given this 12ft inflatable boat with an aluminium floor which will be better for ROV operations than my RIB which doesn't have much clear deck space and it's easier to launch and recover in reservoires etc without a launching ramp. it was full of holes and was actually an un-inflatable boat when I got it but I've patched it up and it's all good now.

[Oddmar]

Yeah, my boat will be a custom-built 28' pontoon boat, two rows of plastic 55gal drums down each side, boat expandable sideways to 14', cabin roof raises/lowers to make the boat 7' tall on the road to 11' tall (8' ceiling) on the water, small kitchenette and bathroom, 14' square control room with 2 720p projection monitors, 14'x10' moon pool room. Moon pool will be 6.5'x8', with overhead double gantry cranes for lowering the 2 ROV's into the water, also for heavy object retrieval.
Of course i'll be hacking it together myself, like i do everything.

[bigbadbob]

Now THAT'S a ROV boat.
love it!!!
I like the moon pool idea, last time I played with a moonpool we had a 6ft surge in it in bad weather, I got wet.

on a different topic I got talking to a guy on e-bay selling fibre optic analog video transmitters off cheap as project boxes, turned out he had receivers as well and I got a pair + a video amplifier for £20 posted. one day I'll try running my video and control over fibre If I work out a way to seal the connectors.
Unfortunately he's sold all the transmitters for £2 each and is left with the receivers which are no use without the transmitters.
he offered me 13 pairs for £100 at one point which I could maybe have sold on here at cost price but also could have been landed with £100 worth of boards no-one wanted and I didn't have time to do market research as the transmitters were selling fast and most buyers probably pulled out the board and ditched it. personally, I'll ditch the box and use the tx board.

[Oddmar]

For a year i've been looking at the BlueRobotics FathomX boards, which send ethernet over 2-wire twisted pair, but they want $160.

I just found a pair of units on Amazon that send ethernet over twisted pair or coax (100mbps over coax) for $49. I bought 2 pairs. Shipped was $106.
https://www.amazon.com/gp/product/B07L6X94XS

[MarcoMota]

For a year i've been looking at the BlueRobotics FathomX boards, which send ethernet over 2-wire twisted pair, but they want $160.

I just found a pair of units on Amazon that send ethernet over twisted pair or coax (100mbps over coax) for $49. I bought 2 pairs. Shipped was $106.
https://www.amazon.com/gp/product/B07L6X94XS

Amazing! Keep us posted. What is the limit of ethernet devices you can use with this method, if there is one?

[Oddmar]

Well, it's limited by the bandwidth, 75mbps via twisted pair, or 100mbps via 75-ohm coax. I'll be using coax as my tether..

Other than that it's a normal ethernet connection, so use a 4-port switch (hub, router) in the ROV. My ROV will have a 36" long 8" diameter 3/8" wall aluminum WTC, with a 1/2" (minimum) thickness acrylic hemisphere custom-blown for me by CDS https://plastic-domes-spheres.com/ who quoted me $140 ea. So plenty of space for electronics. Battery compartment will be separate.

1 port will be incoming from the ethernet transceiver.

1 port out to the Raspberry Pi 3B, which controls the Pixhawk autopilot which controls the thrusters. On my ROV the Raspberry Pi will also be running Python code to control an SSC32U servo-controller via I2C which will control the dual 9-dof manipulators, led lighting, camera pan/tilt/zoom, ballast release, active buoyancy, sample tray deployment, silt vacuum, etc.

1 port connected to an 8-camera security-system DVR stripped down and mounted inside the ROV, for 8 camera views multiplexed onto one screen topside viewed in Chromium web browser.

That leaves 1 port, if you have any bandwidth left...maybe an IP camera?

[bigbadbob]

Not done much to the ROV lately but did add outrigger blocks to the thrusters to give it better manouverability.
And added a non return valve to my pneumatics to keep compensator pressure in the hull when I vent the gripper pressure to open it.