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Multi-camera setup project.

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Offline mphx

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Re: Multi-camera setup project.
« Reply #150 on: 02 / September / 2014, 05:15:41 »
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How are you powering the hubs and cameras?

Could it be the case that the power supply is the cause of your woes, rather than the hubs themselves?

A previous rig suffered from earthing (electrical grounding) issues. You might like to take a look at this thread http://chdk.setepontos.com/index.php?topic=10385.120

There are 8 tripods with 8 cameras on each one.On every tripod there is one 9-10 port power outlet + 1 hub.

Every camera has the dummy battery kit (chinese one :) since original is too expensive) and a usb cable going to the hub.

At this point all 8 hubs are going directly to one pc to avoid more problems with more hubs .

We had one tripod (8 cameras) working all day long without any camera lose connection...we are talking about 4-5 hours..doing stuff...we hooked up a second tripod...16 cameras total... we had 90% stability..one or two cameras..losing connection...but not very often.
We managed to make all 64 cameras work at some points but it was..moments...shoot once or twice...download files and that was all before some camera(s) lose connection again.

So we are thinking that the problem occurs when we have many cameras "online".It's either hubs or cables (we use 3m usb cables on all cameras and we are planning to change some of them to shorter ones).

I don't know about power grounding...i mean if it creates problems or not in my case....i can't check it ....

Re: Multi-camera setup project.
« Reply #151 on: 02 / September / 2014, 05:47:41 »
We having the same issues with cameras connectivity,
But it looks like power to USB hubs and tying the USB cables solved 95% .

Another question , how do you control on camera setting ? ISO , speed shutter ,aperture ?

Regards

Re: Multi-camera setup project.
« Reply #152 on: 02 / September / 2014, 08:50:07 »
I don't know about power grounding...i mean if it creates problems or not in my case....i can't check it ....
This is almost certainly a grounding problem on the low voltage side. 

Unless they are specifically grounded via their power cords, the low voltage side of each of your camera power supplies and each of the USB hub supplies essentially "floats" at some random voltage level above ground. The thin USB 5V gnd wires in your USB cables are the only thing connecting them together and you can get noise and significant DC voltage drops across those wires.

The best and only way to fix this is a heavy wire (at least 8 ga. or 3.26 mm) connecting the various D.C. grounds together.  That usually means the sleeve side of each DC connector - both the USB hubs and camera power supplies.

Finding a tidy & elegant way to do this can be difficult.   You could use a thin wire on each of your tripod poles to connect the power supply DC grounds and then a thick wire between tripods. 

At a minimum, connect via a thick wire the USB ground pin from one port on each hub to a port on every other hub.  That should get you 90% of the way there.

Post a picture of your USB hubs,  power supplies, and camera power supplies?  Or a link to where you bought them?
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Multi-camera setup project.
« Reply #153 on: 02 / September / 2014, 08:54:21 »
Another question , how do you control on camera setting ? ISO , speed shutter ,aperture ?
Did you read my response the first time you asked this ? 
http://chdk.setepontos.com/index.php?topic=11583.msg116233#msg116233

Hint : USAGE.TXT line 268
Ported :   A1200    SD940   G10    Powershot N    G16


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Offline mphx

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Re: Multi-camera setup project.
« Reply #154 on: 02 / September / 2014, 14:47:40 »
Post a picture of your USB hubs,  power supplies, and camera power supplies?  Or a link to where you bought them?

we have used 3 different kind of usb hubs..practically 2 kinds..since one kind of them turned out to be too lousy...

we use some of them -> http://www.amazon.co.uk/gp/product/B002ZU7HH2/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

and i am expecting some of them --> http://www.amazon.co.uk/gp/product/B005NGQWL2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

and we are using some digitus usb hubs ( 10 ports i think)..i can't recall the exact model.

Digitus and Manhattan should be pretty good..especially manhattan...if i judge from its price.anker has good reviews..but i haven't use any yet..i am expecting them.

As far as dummy battery kits are concerned , we are using the classic ACK-DC90 kit , but a chinese version of it...not the original

Both hubs and kits don't have ground "pin" in their power cord outlet...so naturally i assume nothing is grounded..

Pfff it's gonna be messy to ground all these things...

« Last Edit: 02 / September / 2014, 14:49:46 by mphx »

Re: Multi-camera setup project.
« Reply #155 on: 02 / September / 2014, 15:57:57 »
Hint : USAGE.TXT line 268

looks like 368. [edit: oops rev 655  :-[ ]

Another question , how do you control on camera setting ? ISO , speed shutter ,aperture ?

via ptp in isolation from the shoot options ?
« Last Edit: 02 / September / 2014, 17:06:00 by andrew.stephens.754365 »

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Offline reyalp

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Re: Multi-camera setup project.
« Reply #156 on: 02 / September / 2014, 16:21:46 »
There is no specific error and it doesn't occur in a specific moment..it can happen during "connecting" or during sync/shoot or during download/delete.It just pops a blank error window and when i see it i know that one or more cameras have lost connection.
I explained previously how to make this give you a more informative error message: http://chdk.setepontos.com/index.php?topic=11667.msg116130#msg116130

Did you try a linux host? If nothing else, linux system logs might provide more information about what is actually going on.

I would not be at all surprised if the is a hardware issue (power, grounding, cabling, hubs...) but I also wouldn't be surprised if it were a software issue.

I've never used chdkptp with more than 3 cameras, so this is unknown territory for me.
Don't forget what the H stands for.

Re: Multi-camera setup project.
« Reply #157 on: 02 / September / 2014, 16:23:26 »
@ waterwings , I read your reply but still I dont get how i can use it once Bcam is running 

In general - I found it is possible via ptpCamGui (pic attached)

Regarding the wiring, we used cheap USB hubs (the cheapest we could get) , but we had lucky , it have on/off 5v power switch per port so it was easy to by pass it with RELAY

http://www.ebay.com/itm/Black-7-Port-USB-2-Power-Hub-High-FNRG-Speed-Adapter-Separated-Switch-Laptop-/141142475386?pt=LH_DefaultDomain_186&hash=item20dcbf427a

we built 4 control box to aggregate 7 Cameras USB .

Important Note - we found that we must tied thee cables (using plastic strip)

 


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Offline reyalp

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Re: Multi-camera setup project.
« Reply #158 on: 02 / September / 2014, 16:31:42 »
Hint : USAGE.TXT line 268

looks like 368.
Line numbers probably aren't useful unless you specify a revision  ;)

I replied in the other thread, but for any future readers, the above appears to refer to the "shoot" CLI command, which will not help you set exposure in a multicam setup. The code may provide a useful reference, but if you are using multicam you will need to set the exposure by calling lua functions on the camera. In multicam, this can be done using the 'call' command.
Don't forget what the H stands for.

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Offline mphx

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Re: Multi-camera setup project.
« Reply #159 on: 02 / September / 2014, 16:33:49 »
There is no specific error and it doesn't occur in a specific moment..it can happen during "connecting" or during sync/shoot or during download/delete.It just pops a blank error window and when i see it i know that one or more cameras have lost connection.
I explained previously how to make this give you a more informative error message: http://chdk.setepontos.com/index.php?topic=11667.msg116130#msg116130

Did you try a linux host? If nothing else, linux system logs might provide more information about what is actually going on.

I would not be at all surprised if the is a hardware issue (power, grounding, cabling, hubs...) but I also wouldn't be surprised if it were a software issue.

I've never used chdkptp with more than 3 cameras, so this is unknown territory for me.

A try with linux host is scheduled in the next days.I believe too that is a hardware issue since either in cli or gui..."behavior" is rather the same...will do a linux host try and see if things there are the same or any different .

I will try to implement what you suggested for the error message "catching"


We are thinking to use 4 laptops with 16 cameras to each one of them (2 tripods that is). We did some tests today...but even with 2 tripods connected to each laptop (we used 2 laptops for some early testings) , connection of the cameras was not stable.
And of course is the problem how to sync "hitting shoot" on 4 laptops ....that would be tricky...Linux is not an easy option at the moment...but we will go there if nothing else works...
« Last Edit: 02 / September / 2014, 16:39:22 by mphx »

 

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