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 Subject :Homebrew Power over Ethernet.. 2013-03-15- 04:45:00 
N7SKV
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Joined: 2013-03-05- 10:33:11
Posts: 10
Location: Peoria, Arizona DM33uq

If you want to power your HSMM-MESH with your ethernet cable you can use pins 4,5 and 7,8 to supply the voltage to your router. Data is transmitted and recieved on pins 1,2,3,and 6.  So the easiest way would be to cut you power supply and wire positive lead into the cable on wires 4 and 5, the negative lead into wires 7 and 8. I would make sure to cut these wires so they DO NOT lead back into your computer (just a precaution) On the router end you have a choice you can take these pins and make internal jumpers on the router to the correct pins on your power adapter, or make a jumper with your existing left over pigtail. As we all have some technical experience I suggest you use a VOM and double check all your connections before powering up. Ethernet cables commonly use blue and blue/white as 4,5. Brown and brown/white as 7,8. (AGAIN DOUBLE CHECK) keep in mind the longer your cable run the greater your voltage drop.

N7SKV

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N7SKV
 Subject :Re:Homebrew Power over Ethernet.. 2013-03-20- 13:42:05 
K7NYS
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Joined: 2013-03-10- 16:40:27
Posts: 10
Location: Phoenix
Do these routers need the full 12 volts Or how low can they go?
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 Subject :Re:Homebrew Power over Ethernet.. 2013-03-20- 15:49:24 
N7SKV
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Joined: 2013-03-05- 10:33:11
Posts: 10
Location: Peoria, Arizona DM33uq
They will run down to 5 volts, using POE you should have no problems going out to 100ft with good quality cable.
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N7SKV
 Subject :Re:Homebrew Power over Ethernet.. 2013-03-20- 17:31:04 
K5KTF
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Location: 5' from this webserver
  

That is the general rule.

I had one hardware version (cant remember exactly which one) that over 50' of CAT5e (up a pole outside), it was flaky, so I changed out the wall wart for a 13 or 14VDC one I found in my box of warts, and everything stabilized.

Could have been amperage, though. Dunno.

The symptom was that the router would boot, and would visible on the mesh, most of the time. It would just be generally flaky when trying to connect to it, comes and goes, so I thought it may be voltage drop. Once I bumped up the power, it was all good and is still running today on it.

KTF


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 Subject :Re:Homebrew Power over Ethernet.. 2013-03-21- 03:06:16 
wx5u
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Joined: 2013-01-02- 00:30:45
Posts: 188
Location: Austin, TX

Keep in mind that the WRT-54G version 1 only takes 5 volts and will be damaged by 12 V.

I vaguely remember someone saying that the 12 V versions of the router would take a fairly wide voltage range, including more than 12 V.

This page seems to indicate 4-16 V supply is OK, but there's such a wide range of hardware for the 54G series that I wouldn't take that as true for all models without further verification.

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Check out the free Wireless Networking Book
 Subject :Re:Homebrew Power over Ethernet.. 2013-06-08- 16:33:20 
K7NYS
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Joined: 2013-03-10- 16:40:27
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Location: Phoenix
Would you be willing to build a POE cable for me?
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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-08- 16:33:30 
K7NYS
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Joined: 2013-03-10- 16:40:27
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Location: Phoenix
Would you be willing to build a POE cable for me?
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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-08- 16:35:22 
K7NYS
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Joined: 2013-03-10- 16:40:27
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Location: Phoenix
Would you be willing to build a POE cable for me?
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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-08- 16:35:27 
K7NYS
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Joined: 2013-03-10- 16:40:27
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Location: Phoenix
Would you be willing to build a POE cable for me?
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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-09- 03:47:29 
KJ4AJP
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Joined: 2013-03-24- 12:21:59
Posts: 35
Location: NW Tennessee EM56ni
 

K7NYS asked:
> Would you be willing to build a POE cable for me?

The cable itself would be any standard Cat5/Cat5e/Cat6 jumper of the length you need. 

The issue is the POE injector that puts the voltage on the cable and then how to get the voltage to the router.  Commercial POE injectors assume the device on the other end is capable of being powered by POE, I don't think the WRT54 is.  So you have to get the voltage off the cable and then get it into the router.  Take a look here: 

http://kj4ajp.mambm.com/POE.pdf

The most common jumper cable sold for data use is color-coded to the 568B scheme (the 568A scheme swaps orange and green pairs, and is used primarily for POTS telephone, rather than data, wiring).  It's fairly simple to put a wallplate with two jacks in a schedule 40 PVC electrical box (all available at home improvement stores) and then put power connections (+V connected to both blue wires, -V connected to both brown) on one jack and leave the blue and brown disconnected on the jack for the equipment to plug into.  The orange and green need to be connected to both jacks so the data gets through.  You would need to build two of these boxes for each router, one for the router's power supply to plug into and the other at the router.  You're basically using the (normally) unused blue and brown pairs in the cable as an extension cord.

You could simply cut the wire on the wall-wart and connect the wall wart itself to the ground-level POE box and then connect the coaxial plug to the top-of-the-tower router-side POE box, but K5KTF brings up the point of erratic operation with long jumper lengths.  If you're extending what used to be a 3' length of 24AWG power cord to 53', you have to remember that although you're using two 24AWG wires for both + and - on your jumper cable, you're going to get some voltage drop.  That's why the higher voltage wall-wart got K5KTF back to correct operation. 

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Last Edited On: 2013-06-09- 04:07:18 By KJ4AJP for the Reason
 Subject :Re:Homebrew Power over Ethernet.. 2013-06-09- 05:28:15 
K5KTF
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You CAN open the WRT, take the board out of the plastics, flip it over and add a jumper that shorts Pins 4 and 5 and then over to the + on the barrel (DC IN) and pins 7 and 8 to the - (minus).

That way you dont need a splitter on the top end.

One positive side effect to this mod is that if you have another 12VDC device up top with the node, you can use a double-barrelled cable (male on both ends), and go from the DC IN on the node to the 12VDC in on another device, as the power comes up the CAT5 into the RJ45, leaving the barrel jack unused but now with 12VDC available.

Just watch your amps. I dont know the specs on the RJ45 connectors (both on the cable and in the node), but it can supply a small TWELVE VOLT webcam nicely (emphasis on 12V, as many IP cams are FIVE VDC! but you can use UBEC or other regulator off the barrel to feed such things).

At CPRMC hospital, we have 2 nodes up in the box, and we feed the second node exactly like this. We DID put in an adjustable PS in the attic, which we then adjusted for proper 12/13VDC out the top end with both nodes operating.

Happy Meshing!

Jim

K5KTF

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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-10- 05:13:48 
wx5u
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Joined: 2013-01-02- 00:30:45
Posts: 188
Location: Austin, TX

This is not "PoE" or "Power over Ethernet," which is a defined standard.  We should probably not use that term.  Official PoE involves a smart PSE (Power Source Equipment) to supply power and a smart PD (Powered Device) to tell the PSE that it's capable of receiving power.   If someone plugs a "standard" PoE device to one of our homebrew nonstandard RJ-45 plugs, damage might result. 

Also, although 10 and 100 Mbs devices only use 4 wires, Gigabit ethernet devices use all 8 wires for signal.  Plugging one of our bootleg ethernet powered connectors into a "standard" gigabit ethernet device, it might cause damage.   For that matter, even a 10/100 Mbs device might have the other 4 pins hooked up to something.

This could get really bad if you're at a site where someone other than you might be working on the equipment.  If your buddy Joe is working on your HSMM repeater site and decides to plug his laptop into your "ethernet" cable, you might damage something.


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I'm not part of the development team, so take what I say with a grain of salt. I'm also easily confused.

Check out the free Wireless Networking Book
 Subject :Homebrew Power over Ethernet.. 2013-06-10- 05:18:07 
wx5u
Member
Joined: 2013-01-02- 00:30:45
Posts: 188
Location: Austin, TX

There's a risk here, too.  If someone later takes that particular WRT, plugs in a regular WRT power supply, then plugs that WRT into a network, you're now feeding 12V back onto the signal wires into your gigabit capable switch. 



[K5KTF 2013-06-09- 05:28:15]:

You CAN open the WRT, take the board out of the plastics, flip it over and add a jumper that shorts Pins 4 and 5 and then over to the + on the barrel (DC IN) and pins 7 and 8 to the - (minus).


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I'm not part of the development team, so take what I say with a grain of salt. I'm also easily confused.

Check out the free Wireless Networking Book
 Subject :Re:Homebrew Power over Ethernet.. 2013-06-11- 02:30:35 
KJ4AJP
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Joined: 2013-03-24- 12:21:59
Posts: 35
Location: NW Tennessee EM56ni
 

wx5u -> Plugging one of our bootleg ethernet powered connectors into a "standard" gigabit ethernet device, it might cause damage.
<snip>
wx5u -> If your buddy Joe is working on your HSMM repeater site and decides to plug his laptop into your "ethernet" cable, you might damage something.

No, Joe might damage something.  Your FCC license gives you the leeway to experiment with your equipment, and if you're going to modify anything it stops being "plug and play".  So if you authorize Joe or anyone else to work on your system, you need to train them in any peculiarities of its installation and operation.  If they work on it without your authorization and training, then they take on the obligation of any smoke that gets out.

wx5u -> This is not "PoE" or "Power over Ethernet," which is a defined standard.  We should probably not use that term.

How about "Power over Ethernet Cabling" (POEC)?

Actually I like POTSAC (Power Over Too Small A Conductor).  Wink

--
KJ4AJP

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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-11- 14:26:51 
VA7WPN
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Joined: 2013-04-29- 12:21:43
Posts: 60
Location: BC, Canada
 
This is all mish mash. Its all about the experimenting right? What I have done is gone a step further, and put in some diodes. This prevents feed back from the power adapter back threw the WAN port. That keeps the attached equipment safe. I also label my Modified Routers as MODIFIED.
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 Subject :Re:Re:Homebrew Power over Ethernet.. 2013-06-11- 22:09:25 
KJ4AJP
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Joined: 2013-03-24- 12:21:59
Posts: 35
Location: NW Tennessee EM56ni
 

Mine will remain unmodified, and the reasoning is that in the event mutual aid is needed, unless everyone involved in the deployment has spares for their modified equipment, there is no universal compatibility if a unit fails and needs quick replacement.  If my modified router goes out, Joe can't bring in his unmodified router to replace it. 

If one chooses to power their routers over the TP rather than a separate, larger gauge cable, then a box at each end like I originally proposed makes more sense.  The boxes are universal for either side, and with PowerPoles on both your PSU and a coaxial jumper for the router, you're set.  All you have to do is train an op on what the"Equipment" and "Cable" labels on the jacks mean.

Personally, I wouldn't do a permanent install of a $20 device designed for a indoor environment on a tower any higher than I could reach with a 10' stepladder.  I'd be spending the money on an amp and have my radios at ground level.  I realize we're Hams and experimenters and on a budget, but with all due respect to Titan Wireless and Fab Corp, take a look at how it's really done:

https://www.tessco.com/yts/systems_supported/base_station_infrastructure.html

--
KJ4AJP



[VA3WPN 2013-06-11- 14:26:51]:

This is all mish mash. Its all about the experimenting right? What I have done is gone a step further, and put in some diodes. This prevents feed back from the power adapter back threw the WAN port. That keeps the attached equipment safe. I also label my Modified Routers as MODIFIED.

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 Subject :Re:Re:Re:Homebrew Power over Ethernet.. 2013-06-12- 08:01:32 
K5KTF
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Joined: 2010-01-18- 23:04:04
Posts: 266
Location: 5' from this webserver
  

K5KTF-50foot has been up on the push-up pole now for about 3 years, in the plastic Orbit box mind you, and has had no problems, running 14VDC up about 60' of regular cheap CAT5e (not even plenum rated) cable. Yes the sheathing may be starting to crack in places on the wire, but its still cooking.

I have taken it down for other things (webcam & other things), but the same board in the same box, and it even survived the 110*+(F)-for-80+days Central Texas drought of 2011 without a glitch.

-50foot is my longevity experiment... passing so far.


KTF




[KJ4AJP 2013-06-11- 22:09:25]:

Personally, I wouldn't do a permanent install of a $20 device designed for a indoor environment on a tower any higher than I could reach with a 10' stepladder.  I'd be spending the money on an amp and have my radios at ground level.  I realize we're Hams and experimenters and on a budget, but with all due respect to Titan Wireless and Fab Corp, take a look at how it's really done:

https://www.tessco.com/yts/systems_supported/base_station_infrastructure.html

--
KJ4AJP


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 Subject :Re:Re:Re:Re:Homebrew Power over Ethernet.. 2013-06-12- 11:43:51 
KJ4AJP
Member
Joined: 2013-03-24- 12:21:59
Posts: 35
Location: NW Tennessee EM56ni
 

Good to hear... seriously.  Since you're an Admin and responding, would you like to take a stab at the question I've posed 3 times so far without a response?  (I did get a response, but it was from someone scolding me for using LMR400 rather than Cat5... but ignoring the actual question). 

How do you test to see what antenna port is what?  I have a router with a bad RP-TNC jack I did a eBay "Make Offer" and got for a song.  I soldered a 47 ohm resistor on the broken jack side as a dummy load, then put enough LMR400 on the good RP-TNC to get a 12dBi panel antenna out of the shop so a wireless utility on a laptop wouldn't get signal from the dummy load.  I switched both TX and RX to Left, and then to Right in the firmware, but there was no difference in signal level.  Is the router going to send out a carrier to both antenna jacks no matter what, and only one have data on it?  Do I need to take another node out to see which setting actually passes data?
--
KJ4AJP



[K5KTF 2013-06-12- 08:01:32]:

-50foot is my longevity experiment... passing so far.


[KJ4AJP 2013-06-11- 22:09:25]:

Personally, I wouldn't do a permanent install of a $20 device designed for a indoor environment on a tower any higher than I could reach with a 10' stepladder. 


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 Subject :Re:Re:Re:Re:Re:Homebrew Power over Ethernet.. 2013-06-12- 12:03:34 
K5KTF
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Joined: 2010-01-18- 23:04:04
Posts: 266
Location: 5' from this webserver
  

Truthfully, I think it depends on the model number of the hardware.

I have played with a number of them, and with most,  I cannot tell if there is a difference when I kick them left or right or diversity.

I think I found one where where I could actually tell the difference, so usually I just leave mine in diversity and let IT figure out the best jack to use.

Maybe the GL's do more or something, as I dont play with those much (I usually keep on the lookout for Gv2's so I can make more USB nodes, or GSv2 to make application nodes)

What I would do, to test, is have a known AP off as far as you can, then hook a directional ant to one port, and kick the setting back and forth, while looking at wifi scan. Maybe even rotate polarity as well (30db drop). Those of us without a VNA (analyzer) have to just shoot in the dark..

Sorry I couldnt help more, but that has been my experience over the last 3+ years.

73

KTF



[KJ4AJP 2013-06-12- 11:43:51]:

How do you test to see what antenna port is what? 

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 Subject :Re:Homebrew Power over Ethernet.. 2013-06-12- 12:05:13 
K5KTF
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Joined: 2010-01-18- 23:04:04
Posts: 266
Location: 5' from this webserver
  

BTW, if you want, I have a couple dead wrt's that have perfectly good RP-TNC's that can be scarfed from (I have already grabbed some parts off them)

Or, you can always take the coax right to the PC board from an N connector in an enclosure or something. We have done that, removed the TNC's and wired straight to N's.

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Last Edited On: 2013-06-12- 12:06:28 By K5KTF for the Reason
B-) Jim K5KTF EM10bm Cedar Park, TX :star:
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