Reading xEM with Proxmark3 Easy - Positioning Tips


#1

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.

Proxmark3Easy_lf_read


#2

I will try it tomorrow :slight_smile: Thx


#3

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.


#4

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.


#5

High Frequency tags such as xNT:

Low Frequency tags such as xEM: