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sdack underwater rig (was Re: Ultimate Intervalometer - a script for shooting over a long duration -

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Offline Sdack

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Morning!

Regarding the black frames, I didn't change the camera exposure setting to A intentionally but I guess it's possible that I may have accidentally.  Having fat fingers, I do find the rotary dial a bit of a fumble.

However my plans have all changed.  Yesterday, after a good test run with the super, one-shot.lua script, that you made for my ultra low power Arduino setup, I realized that batteries simply just aren't going to cut it on the project to to capture a month of plant growth.  I did run two cameras for an hour on 0.6W/h of energy but that's still 432 W/h over 30 days.  Even if I separate the power for each unit I can't squeeze an RV battery inside a modest underwater video camera housing

I also found out that I have access to a 12 volt Solar system that's onboard the raft which forms the base of the prototype seaweed farm that I'm going to document.  So the whole game changed in the course of one conversation with my friend, who got me involved in the project.

The second major boon came when we had it confirmed that mobile phone reception is available (we're talking 5km offshore the north coast of Bali, so we were rather doubtful).

So, now we're going with a new configuration consisting of a 'base station' waterproof case containing two wifi enabled Raspberry Pi Zero W's connected to a wifi 3/4G mobile data modem.  Cat6, waterpoof cable will run power and data down to the two underwater housings each holding only an Ixus 160s and a buck converter to drop 12V down to 4.2V.

Yes, I'm concerned about drilling holes in the housings, but at least with this set up, if worst comes to worst, I'll only drown a camera and a buck converter and I will have all images stored safely on the Raspberry Pi and uploaded to the Internet.

The only remaining test to do today is to make sure that a 25m power and data over ethernet cable will successfully communicate between the Raspberry Pi USB port and the mini USB port on the Ixus.

If anyone's tried such a feat, I'd appreciate any tips.  Maybe there's a way to boost the signal?  I've seen USB extension leads for sale online and some of them have lumpy bits near the connectors but what they contain I don't know.

I hope you don't feel I've wasted your time with my Ultimate explorations.  It's not the script that fails to meet my needs it's simply the power required for the length of the job.
Cheers
Sdack

Regarding the black frames, I didn't change the camera exposure setting to A intentionally but I guess it's possible that I may have accidentally.  Having fat fingers, I do find the rotary dial a bit of a fumble.
Putting it in A would have been fine.  As I posted earlier,  I think what you were seeing is the lowest speed / f-stop / highest ISO value that the camera will pick in low light situations.

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However my plans have all changed. 
Sound like a good new plan.

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Yes, I'm concerned about drilling holes in the housings, but at least with this set up, if worst comes to worst, I'll only drown a camera and a buck converter and I will have all images stored safely on the Raspberry Pi and uploaded to the Internet.
Assuming the housing has an "up" and "down", put the holes in the bottom.  That way if they leak, they will pressurize the house as they fill from the bottom and then will stop filling.

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I hope you don't feel I've wasted your time with my Ultimate explorations. 
Not at all.  It wasn't exactly a big time investment.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline Sdack

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Assuming the housing has an "up" and "down", put the holes in the bottom.  That way if they leak, they will pressurize the house as they fill from the bottom and then will stop filling.

Funny.. I woke up this morning thinking the exact same thought.

Thanks for your understanding WW

Sdack

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Offline reyalp

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FWIW, those black frames look suspiciously like hardware failure to me. 1/8 at f3.2, ISO800 should show *something* at 9:00 AM outdoors under almost any weather conditions at aus latitudes.
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The only remaining test to do today is to make sure that a 25m power and data over ethernet cable will successfully communicate between the Raspberry Pi USB port and the mini USB port on the Ixus.
USB 2.0 is limited to 5 meters between devices. I wouldn't expect 25 to work with plain cable.

Some USB extender cables (e.g. https://www.amazon.com/dp/B006JTOQN8/ref=psdc_464394_t1_B00GLZYG6M) just have hubs in between, which increases the allowable delay. You probably won't be able to send the required power through something like this.
Don't forget what the H stands for.


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Offline Sdack

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Hi Reyalp,

Thanks for your suggestion but I think you are mistaking my need.

It's actually only the USB data part I'm concerned about.  The power will work for sure.  We're talking about a POE (Power over Ethernet) injector approach here ie. I will split open a Cat6 cable so that two of the four twisted pairs become the positive and ground of my 12V DC.  This works just fine over 50 meters on a rig I've had running for the last couple of months.

Where this use case differs is that the Raspberry Pi will be at the near end of the cable, on the base raft, above the water, where the power source is, instead of in the underwater camera enclosure next to the camera.  So it's the USB data connection (the CHDKPTP connection), between the Pi and the Ixus that I'm unsure of.

Cheers
Sdack

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Offline Mlapse

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the poe approach will most definately work over 25 meter. but data over usb is as reyalp points out limited (stable) to about 5 meter. if you want more you would need an powered usb hub every 5 meters to prevent signal degradation. I am suspection this is not really possible in your setup.
Might have to put the raspberry under water with the cam, so they can both be powered via poe and pictures can be retrieved above water via that lan cable and usb can be short....where is my silicone gun?
« Last Edit: 28 / September / 2018, 06:43:42 by Mlapse »

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Offline Sdack

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Thanks MLapse, Reyalp,
I guess if I have to have two Pi's in the enclosures to be near enough for USB to work with the camera, I could just add a third Pi above the surface and a router with all the pis connected via the data strands of the POE?
Cheers
Sdack
« Last Edit: 28 / September / 2018, 08:53:38 by Sdack »

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Offline Mlapse

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the topic heading is somewhat off, shouldn't you move to a new topic?

most routers use a 12v adapter, just dump the adapter and there you have your 12v router, if your router does not use 12v get another buck converter.
some have usb ports for a mobile network and/or nas/ftp server functionality, hook up a hdd and 3g/4g modem.........
i use a fritzbox for something like that (wifi off), but i do not know if they are available in aus plus they might use more power than yet another raspberry above the waterline....
« Last Edit: 28 / September / 2018, 08:46:02 by Mlapse »


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Offline Sdack

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Oops,
You replied while I was editing my last post.
Yes you're right. I've wandered off into the woods here.
I think I'm on the right path now
Thanks for the feedback
Sdack

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Assuming the housing has an "up" and "down", put the holes in the bottom.  That way if they leak, they will pressurize the house as they fill from the bottom and then will stop filling.
Funny.. I woke up this morning thinking the exact same thought.
I woke up thinking about this too.  And about how the water pressure outside the enclosure goes up one bar (or atmosphere or 14.7 PSI) for every 33' of depth.  So the air inside the enclosure is going to compress until its pressure matches the water pressure.   At 100' depth, that means your enclosure will fill up until it's 3/4 water inside - which means you need a deep enclosure with the camera stuff mounted only in the top 1/4 of the depth for this to work.

Better do a good job sealing the connectors / cables I think.
Ported :   A1200    SD940   G10    Powershot N    G16