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Author Topic: ROV - It *has* to be done...  (Read 25723 times)

  • Offline zpyder

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ROV - It *has* to be done...
on: April 10, 2013, 19:02:14 PM
So at work we've replaced one of our Gopro Hero 2's (it got left on a reef :/) with a GoPro 3. These have wifi built in. Got me thinking if there would be a way of getting wifi/signal transmitted to the surface from around 10 metres depth.

A quick search led to this thread:

http://www.goproforums.com/11-mounts-accessories-modifications/970-wifi-bacpac-underwater.html

His idea was similar to what I envisioned would be needed. But furthermore, he captured the example video using a home made ROV, and the guide is here:

http://monitor.noaa.gov/publications/education/rov_manual.pdf

So, I now am scheming to try and do a DIY ROV for use up to around 20 metres depth if possible, on a budget.

Should be fun, especially if it works. Any suggestions on equipment that would handle the wifi stuff. Need small, low power do-hickies.
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #1 on: April 11, 2013, 13:27:00 PM
Any idea how I would be able to power this, or something similar underwater:

http://www.netgear.com/landing/wnce2001.aspx

As it's powerable via USB I guess it doesn't need a big power supply. Run a power cable alongside the ethernet cable from the boat, connected to some small battery setup?
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Re: ROV - It *has* to be done...
Reply #2 on: April 11, 2013, 13:59:01 PM
when you were talking about wireless, I assumed you meant a remove control ROV with no wires going to it...

but reading more of the thread you linked, it looks more like the plan is to stick a wifi to Ethernet adapter to the ROV and then have an Ethernet wire up to the surface?

if that's the case, then the ROV might as well have a power cable and control cable going to it too ? - saves batteries running out and any remote control problems

if so, just power the adapter from the power going to the ROV via a dc-dc converter

any idea what kind of ROV you're going to make, what kind of motors, shape etc. etc. ?  that bit is a lot more involved than the wifi adapter bit

for the wifi adapter, you just need to fine one that works for you, strip the plastic case off, plug in your power and network cable and then encase it in resin (put it in some kind of little box and pour resin ontop) to make it all waterproof

I'm guessing you'll want to use relatively high voltage for the ROV because of the voltage drop along the long thin cable you'll want to use, if you use 72v DC it's high enough to cut down on voltage drop and you can still get motors/controllers etc.. off the shelf

all really depends on how big the ROV is going to be I guess
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #3 on: April 11, 2013, 14:23:31 PM
Cheers Knighty. See the NOAA link for the ROV blueprints. It won't be exactly the same but will be similar.

Currently my priority is actually the camera side of things. We have the "CrabCam" setups already. Now we have the camera with Wifi, there's no reason we can't modify the crabcam procedure so that we can actually get a live feed on the surface to ensure correct placement of the frames, or just drift a boat along on top of the reef with a camera pointed down at it, recording as it goes.

The camera set up will essentially be, from my understanding, the Wifi access point in resin, attached to the side of the camera. From it an ethernet (and power?) cable is run up to the surface. The thread above mentions success with a 50ft cable. At the surface will be another wifi access point/router, which will transmit the camera signal to a tablet computer on the boat/quayside. So I guess power wise, we'll need something able to power the adapter at the camera end, as well as the surface router.

As to the ROV, I think it will be cabled fairly crudely. Bilge pumps and the likes. I've not really looked much into it yet as I'm still trying to process the idea in my head, and figuring out whether I can get the uni to fund it or whether I'll need to do it personally.
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Re: ROV - It *has* to be done...
Reply #4 on: April 11, 2013, 14:43:09 PM
if it's just a camera you want to power for now... use POE (power over Ethernet)

get some decent network cable, and run power down some of the spare wires inside it

you could buy adapters for it, or it's easy enough to wire up yourself

if you need 5v at the underwater end, you might need a little bit more at the surface end, best way to tell is to try it out tbh, wire it up and check the power at the underwater end with a meter (with it turned on)
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #5 on: April 11, 2013, 15:06:39 PM
Would POE work with something like the Netgear WNCE2001? You can tell this is going to be a bit of a learning curve for me :D
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Re: ROV - It *has* to be done...
Reply #6 on: April 11, 2013, 17:24:09 PM
POE will work with anything that's low power

if the off the shelf POE stuff doesn't support it, you can just do it yourself


have you crimped the end of a network cable before ? it's a bit fiddly, but you just slide the wires in and squeeze the crimp tool then you're done
(crimp tool is just like a pair of pliers)

only difference with this would be, instead of poking 8 wires into the crimp, you pull 2 out and crimp a different end for those which plugs into the netgear :-)
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Re: ROV - It *has* to be done...
Reply #7 on: April 11, 2013, 17:26:14 PM
the other option would be a small battery pack... how long do you want to stay under water in one go for ?

or you could us a a few battery packs so if one runs out you just bring it up and plug another in.... I'd think a few hours use would be no problem even with a small battery pack
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Re: ROV - It *has* to be done...
Reply #8 on: April 11, 2013, 17:27:28 PM
p.s. when I say POE, I don't mean proper POE stuff where you just plug the network wire in and it does the rest for you

you'll need a little adapter at each end, or crimp your own connectors on the end
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #9 on: April 12, 2013, 13:54:20 PM
Found an extended version of the NOAA document:

http://physics.gallaudet.edu/rov/doug_levin/

Also, the guy that has followed the blueprints and used a wifi setup has now sorted out a blog documenting his progress and processes:

http://leatherback-rov.blogspot.co.uk/

It's all starting to take shape. I just know though that where the parts are listed at under $100, that'll equate to under £100. I hate it when the £ costs the same in figures, if not more, than $.
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Re: ROV - It *has* to be done...
Reply #10 on: April 12, 2013, 15:44:05 PM
you could easily do better than that Chris!

the bilge pumps with propellers on are a good idea

but his control system sucks

he has 2 wires for each motor running back to the surface to feed power to them from there... but it would be much better to just have 2 wires going down to it feeding power into a little relay box, and then use thing cable (network cable again?) to control the relays (I could do you a wiring diagram if you like, it's all pretty intuitive once you've got your head around it)

that way you have a lot less wires going down to the RV - network cable for camera, network cable for control, and then power wire :-)
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #11 on: August 28, 2013, 20:11:52 PM
So, I'm started to consider this project again.

I'm tempted by the Contour cameras, rather than GoPro as the design lends itself to more applications.

The issue is that they are bluetooth controlled only. So the question is, do "Bluetooth repeaters" exist, that I could use in the same way as the WiFi equipment above?
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  • Offline zpyder

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Re: ROV - It *has* to be done...
Reply #12 on: September 06, 2013, 16:29:56 PM
Ended up going with GoPro.

Officially now in planning stages to make this. It'd be good for my CV and any potential future employment in Marine Biology / Marine Consultancy :D

(plus really fun to do)
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