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Ethernet camera less wires = want

yongjaewon

Oct 27, 2012
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Hi I have an IP camera that uses Ethernet cable as signal and a seperate power source. I need to reduce the number of wires that are needed to send the video signal. Is that even possible? Maybe something like a parallel to serial convertor thing? (I'm not sure). Look I'm not very good at electronics and I won't understand if you throw in jargons without explanation so keep it simple. Thanks. I'll post the camera model number when I go to work tomorrow since it's at my workplace.
 

donkey

Feb 26, 2011
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to keep it very simple show us model numbers.
the likely hood of this being doable is high.
the likely hood of being able to do it without outside help is small,
is this hooked up to a computer or does it use the ethernet cable and connect to a standard tv?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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I'd google "Power over ethernet"
 

donkey

Feb 26, 2011
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what voltage is ethernet?
the only thing I thought would be the issue is making the camera run on that voltage.
 

yongjaewon

Oct 27, 2012
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The model number is Axis 206. The camera is connected via Ethernet to a network bridge and the bridge is wirelessly connected to the computer. Is the camera using all of the wires in Ethernet cable? I'm sure I don't need POE because I have a seperate power source. I need to minimize the number of wires inside Ethernet cable needed to transfer video. Thanks
 

donkey

Feb 26, 2011
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why would you want to do that? are you adding more cameras using one chord?
what you are trying is possible, but a network switch might be cheaper
just let us know the full story before you go hacking into chords or even worse into the camera
 

(*steve*)

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Jan 21, 2010
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POE essentially involves using the unused wires in your ethernet cable to run power to a device.

Some devices implement this internally, most do not.

Yes, you isolate those wires and connect them up to power (in the most basic case).

Why do it? Convenience and less cables. And the "less cables" thing is what you want to achieve.
 

yongjaewon

Oct 27, 2012
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I have a turret that rotates 360 degrees and the camera needs to be mounted on it. Because I can't use wires im going to use contact plates to give it power and get signal. No I can't use wireless camera (robotics competition rules). Making contact plates for unused wire is obviously wasted effort so I want to make hem for only the useful wires.
 

(*steve*)

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You'll need at least 6 connections, 2 for power and 4 for data.

With some extreme trickiness you may be able to send power over 2 of the data lines, but there's lots of reasons I wouldn't.

It *may* be possible to inductively couple power (so no wires)

Why can't you use wireless?
 

yongjaewon

Oct 27, 2012
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I can't use wireless camera because it's for a robotics competition and because of communications interference at the venue. BTW, the network bridge is D-Link DAP-1522. Can you tell me which color wires in Ethernet cable are being used and which colors are not based on the camera model number? If not, is there a way I can test them to see which ones are being used? Maybe use a voltmeter? Or I could give Axis a call to ask. Thanks Steve and Donkey for answering =)
 
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CocaCola

Apr 7, 2012
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Why are you using a wireless bridge if you can't use wireless?
 

yongjaewon

Oct 27, 2012
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This is straight from the rule book: "One D-Link DAP-1522 is the only permitted device for communicating to and from the Robot during the match. All signals must originate from the Operator Console and be transmitted to the Robot via the official Arena hardware. No other form of wireless communications shall be used to communicate to, from or within the Robot (e.g. radio modems from previous FIRST competitions and Bluetooth devices are not permitted on the Robot during competition)."
 

donkey

Feb 26, 2011
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why not use the network cable (cat 5 or cat 6) to send just the data. inside the robot use a microcontroller to recieve said line and send signals to the items. having said that you would need a powerful micro OR something like a raspberry pi for the video feed, as I haven't seen that many good arduino projects with a camera yet
 

yongjaewon

Oct 27, 2012
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How about you save yourself A LOT of trouble, hassle and time and just get say a 12 conductor slip ring?

For $10.59 delivered, you can pass all the existing network and even the power wires...

http://www.ebay.com/itm/Capsule-Com...726?pt=LH_DefaultDomain_0&hash=item4164ba27ce

That's a good idea, but if I were to do that, i would need a large bore slip ring because this robot will shoot basketballs and the balls have to move up through the middle opening (approx. 10in) of the turret. Couldn't find any on eBay. I think Moog has some, but I reckon it'd be over engineering for a turret spinning at 60rpm and also would be cheaper to build one myself.
 

yongjaewon

Oct 27, 2012
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why not use the network cable (cat 5 or cat 6) to send just the data. inside the robot use a microcontroller to recieve said line and send signals to the items. having said that you would need a powerful micro OR something like a raspberry pi for the video feed, as I haven't seen that many good arduino projects with a camera yet

The FIRST robotics doesn't like anyone having an unfair advantage, e.g., some well-funded teams putting several laptops on their robot while a rookie team can only put an Arduino on theirs, so they came up with this rule: "Robots must be controlled via one programmable National Instruments cRIO (part # cRIO-FRC or cRIO-FRCII), with image version FRC_2012_v43. Other controllers shall not be used."
 
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CocaCola

Apr 7, 2012
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Well one thing is clear, with every suggestion you toss up a rule that forbids it... So at this point I'm going to stop suggestions to make your life easier and suggest you Google 'ip camera to coaxial' yes they are expensive but they will drop your camera down to two wires just as you requested...

BEWARE that even those devices (like most if not all solutions that you will find for this) will have a 'controller' in them and thus likely violate the rule above...
 

yongjaewon

Oct 27, 2012
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Well I reckon the cheapest and easiest way to do this LEGALLY is figuring out which wires inside the Ethernet cable the camera is using to send signal and making a custom slip ring for those wires only. I'm gonna give Axis 206 a call for that info. I'll post the result. Thanks CocaCola
 

CocaCola

Apr 7, 2012
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Well I reckon the cheapest and easiest way to do this LEGALLY is figuring out which wires inside the Ethernet cable the camera is using to send signal and making a custom slip ring for those wires only. I'm gonna give Axis 206 a call for that info. I'll post the result. Thanks CocaCola

You don't seem to understand it's not that easy, the camera is using IP protocol, thus the information is bundled and sent as network packets, these packets contain a header and payload... The really short of it, is that you need to decode and read the packets as they arrive to get the video stream... There are simply NO simple couple of wires you are going to find that have the 'signal' there are 4 wires used two transmit and two receive they work together... Look up network pinout diagrams to figure out what wires those are... The other 4 wires are unused or used for power over use...
 

donkey

Feb 26, 2011
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could you not use a standard camera for surveillance with an rca jack, this would only use 2 wires for signal. then you could use battery inside the bot
 
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