Reading xEM with Proxmark3 Easy - Positioning Tips

I just spent a little time getting some readings with my Proxmark3 Easy and my xEM implants. I was able to determine what works (reasonably) reliably and what doesn’t.

In the diagram below, the blue circle is the antenna, the red lines are implant/chippositions that don’t work and the green lines are implant/chip positions that do work. Essentially, the antenna needs to cross about the middle of the implant/chip in order to get a successful read.
If the implant/chip is in the middle of the antenna circle, it doesn’t read.
If the end of the implant/chip is at the antenna, it doesn’t read.
If the implant/chip is only slightly crossing the antenna, it doesn’t read.

Being careful with that positioning, I was able to get consistently good reads (but often only after a couple of hand/antenna repositions).

I presume that if you hold the position that you got a good read in, that you would be able to get a good write in that same position.



I will try it tomorrow :slight_smile: Thx

Great tips thanks for posting! In short, your observations are correct and can be simplified to this; typical wire coil or PCB printed traces that are flat in nature (not a cylinder) work best if the x-series implant (with a cylindrical antenna) is placed perpendicular to the wire or trace antenna such that the reader antenna rests in the center of the length of the x-series cylinder. That’s why all the green options are exactly that… location on the antenna itself is irrelevant as long as the above holds true.

yup! I wasn’t able to properly comprehend what was meant by “perpendicular” in this 3 dimensional situation, and for some reason, I’d gotten some other positioning into my head. When I saw what the correct position was, I then understood what was meant by perpendicular - I was making it more complicated than it needed to be.

I did this diagram to hopefully help others understand what the correct positioning was.

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High Frequency tags such as xNT:

Low Frequency tags such as xEM:


I can’t found my chip with my fingers, I unknow the real posición and I can’t read with proxmark3 easy :frowning: #fail
Yesterday I onlybread one time my NExT today I try around 30 times and nothing…
With mobile is the same, i know in my mobile the good position (android) but in iPhone max I can’t read . It is very deep

Tengo la antena HF desabilitada. pero la antena LF no me encuentra el NExT, es verdad que lo tengo profundo, pero con el movil puedo leer HF con la practica de tanto utilizarlo.
Alguna sugerencia?
Lo he conseguido leer una vez y me decia que era modelo INDALA pero por mucho que lo vulvo a intentar no lo encuentro, y he hecho las posiciones del inicio del post con todas sus variantes por si acaso.

I am not certain that this is the cause of your issue :man_shrugging:

It might be worth “fixing” it and trying again.

Off the top of my head, it was something like
but the commands were changed “recently”
to something like

So depending on what version you are running, one of those Should work for you.

Again, I am not sure if that is what the issue is, but it’s wort a try

I will find you the CORRECT commands shortly…

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There are further instructions where I got this quote from, it may be worth following it through.

Good luck, let us know how you go