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PoE Reset Circuit for UBNT

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PoE Reset Circuit for UBNT
Hello All,

Does someone have a schematic diagram for the UBNT Reset circuit that is in most if not all of the PoE devices sold by Ubiquiti?
I've seen the forum posts there - and I suppose I could crack one of those open too - I was hoping I could get a circuit here.

I'm designing a custom PoE device; and I'd like to add this feature.  Note meaning the radios we're using here.  It sounds like UBNT
may have changed the circuit for some of the newer devices based on what I've read over on the UBNT forums.

K6AH's picture
A Google search returned:

A Google search returned:

Can you post what this
Can you post what this returns: 73's, John AJ6BC
wa2ise's picture
This is roughly wat the

This is roughly what the ubiquiti nodes have, a transistor in parallel with the reset button.  Though they included a zener diode in series with the transistor base.  I built and tested the circuit in the attached image in a Linksys router, which uses the same reset circuit (push botton that pulls down a reset line, this line pulled up to 3.3V by a 1K resistor.  Apply around +12V on the TX and/or RX lines to activate the transistor and thus causing the reset line to be pulled down.  Inside a remote router or POE box, you place a push button connected to around +12VDC, in series with a 1K resistor (to limit current if the line gets shorted).  You'll need a ground return path, use the brown twisted pair of the CAT5 cable you are using to connect the remote node with for that.  The blue pair would be for the positive supply in a POE system. 

Image Attachments: 
k1ky's picture
Remote Reset inhibit after AREDN Installed?

II noticed there is a "checkbox" to disable remote reset in the UBNT firmware.  Does this setting "survive" an AREDN Firmware load? In other words, to prevent our AREDN flashed nodes from going back to "setup" mode when water shorts out the pins, is the remote reset ability still disabled if we had it disabled via UBNT after loading AREDN firmware??  If not, possibly a feature request suggestions.  There is a downside to not being able to remotely reset a unit as that would mean a trip up the tower....

This is something that I have been intending to test, but my round tuit is lost...

K5DLQ's picture
"Disable remote reset"?????  
"Disable remote reset"?????
k1ky's picture
Disable Remote Reset
In the UBNT Firmware Admin/Setup (the last page) there is a checkbox for this feature.  Do you need a screen shot of it?
Reset button indeed
I too am in need of PoE injector reset button working.
After some success updating to FW  on a couple of other nodes i decided to try the FW update on a node 40 feet up a mast.
The update partially failed and partially worked. I now have a node that is for 15 seconds or so before it appears to lock up
I can even get to the status page in that 15 second window.  Problem is, the node is now is on Channel 11 and has an SSID of MeshNode
the status page shows my call sign as it did prior to the update and even shows being the new firmware version.
I thought the node was locked up but it really was just off the Ham frequencies.

So now i am trying to figure out how to reset  and fix my node without pulling the 40 foot mast down.
I have tried the reset button on the PoE injector but to no avail.  This thread is the closest I could find to my problem.


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