Samsung 2920 poor detection range - will an implant work?

First post, great forum you have here!
I have a Samsung 2920 on my front door and would like to get an XM1 implant to operate it.
Concern is, the keypad/reader seems to have an really shitty range. It needs a card or tag touched right against it, will not even read it through the transparent pocket on a card holder.
Is this unlikely to work with an implant, and is there anything I could do to improve the range? I have a couple of them and am happy to hack them about.
I’ve attached a pic of the antenna section of the reader if that helps any. Security is not a major concern at all, it is just a nice gadget and the PIN keypad is handy if I forget my wallet so I am keen to use the 2920.
Any suggestions welcomed!

There is no real way to know for sure without trying ( Unless somebody else has tried )
I would suggest in order:-

You could ask Amal if he would be happy to receive one of these for you for testing with the implants ( He is very busy at the moment so don’t be offended if he says no )

For testing, before you purchase,Get yourself some facsimiles of the implants I suggest from your preferred shopping site
Aliexpress, ebay, Amazon ( DO NOT INSTALL THESE )
After you have searched if you get stuck finding products, just ask and I’ll see what I can find

I would try to “externalise the antenna”
from what you said about read range, An xM1 would likely struggle but to increase your chance of a read you should present it like this

If that doesn’t work
FlexM1 would be improved chances of a read
Present like this
if that doesn’t work a FlexMT
Present like this

The above :up: would be the most simple before you try to more seriously hack.

Anyway, that is how and What I would try first

Good luck

Super quick search

here is a FlexM1 facimilie

Here is a FlexMT facimilie

Brilliant info, thanks! Amal has confirmed that the Xm1 is compatible, but I just don’t think it has a chance of reading through skin.
I take it there is no way to tweak/replace the antenna for better performance? From some reading I understand that the antenna is designed to work best with the manufacturer’s supplied cards and tags, so would altering it just totally ruin things?

More the fact that it is tuned to that antenna.
It can be done but not as simple as swapping out the antenna unfortunately.

Power output would increase range, ie. fresh batteries would be better, and a constant power supply better again.

So, were you to combine a constant power supply with an external antenna you have increased you read options.

Remember, these are MY starting simple suggestions, Other user on here may have some more ideas for you also

I just tried it with an external power supply - some improvement but not enough. It will read through a 0.50mm sheet of PETG plastic, but not through a thin leather wallet. If I could splice in before the antenna with a 13.56mhz amplifier circuit, would that improve things?
Thanks for the advice! I know it sounds daft to go to all the hassle but I do really like the unit and want to use it!

It could get complicated unfortunately. Each antenna is specifically tuned to the resonant frequency, and if whatever modifications you make change the inductance / capacitance or make it so that the controller cannot also receive field power, then it won’t work.

Without the front of the lock on, can you get a greater read range?

Now, if you wanted to test with something more similar to an implant, you have a few options:

  1. Buy a xFD (field detector) HF from DT, and find sweet spots / check if it’ll light it up at all
  2. Just buy an xM1, which comes with the xFD HF and hope it works
  3. Buy some cheap chinese Mifare glass tags to test read range (DO NOT IMPLANT THIS)
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I’ve just tried it without the cover on, and get a range of about 20mm from the antenna board with a card or tag in free air, but under the plastic of a card holder still needs it to be touched almost to the circuit board itself. I understand the antenna tuning (I used to have a CB radio! :sunglasses: ) - would a simple amplifier chip upset things?
I’m thinking I might nearly be as well just to stick in a reed switch and get a magnetic implant at this point!

Unfortunately, antennas for the RFID applications we’re talking about are quite different to standard antennas - instead of an open ended conductor, they function as an inductor. This is due to the need to transmit power and data at the same time, using inductive coupling.

Don’t give up! Are there any other NFC locks you could try? Is there any chance that the plastic you’ve been trying is metallic / foiled? Could you try some other things between the card and the lock? Another thing to note is that the card might actually have a terrible couple with the reader, e.g. a circular coil for the square PCB antenna. Ideally, you’d want to try some other cards / a field detector.


I have a Yale Doorman lock at my place. Really shitty antenna on it (barely lights up the field detector, and only when held at an angle).

For this reason, I went with a flexM1. I also implanted a xM1 for work, and have tried both implants on my lock.

Now when I use the xM1, it works. But I have to fiddle quite a bit to find just the right angle (and the antenna pulses about once pr sec, so it’s hit and miss sometimes). In short, I’d be disappointed if this was my key, as it is faster to just enter the pin code.

[Edit: however, if it was my only chip, I would probably find the sweet spot for it after some more testing]

The flexM1 however works a lot better. Just slap my wrist on the reader and boom.

It is however also an entirely different thing to stick in your body, so… I’d follow the above suggestions. Get a cheap facsimile and test.
If you really want to test, insert it under the skin of a chickendrum, or better yet, hold a thin bag of sugar water between the reader and the chip,and see if you can get a good read :slightly_smiling_face:

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My experience with the Yale Doorman is slightly different.

Like you, I have to fiddle a bit (too much) with my M1k glassie. But it’s still somewhat livable. In fact, I lived with it more or less fine for months until I got the flexM1 installed.

Unlike you though, I have to fiddle quit a bit with my flexM1 too. No slapping my wrist on the reader and boom for me: about 25% of the times it opens rightaway, 70% it takes some wriggling of my hand and wrist for a few seconds to get it to read the implant and unlock, and 5% of the times it just won’t play ball and I have to revert to the glassie.

I’m not sure whether my Yale Doorman or my flexM1 is subpar. On my other NFC locks, the flexM1 works like a bad coin tag, which I presume is what’s to be expected given the size / geometry of the coil. So I suppose my particular Yale Doorman is to blame.

But one thing’s for sure with the flexM1: if a reader won’t read a glassie, it has a very good chance of reading a flexM1, even if it reads it poorly. That’s its main redeeming feature: it brings the implant into the realm of full-size transponders performances.

That’s weird… At most, I have to twist my wrist a couple of degrees, if it doesn’t read “immediately”

I have in fact 3 Yale doorman locks, but only use it on my front door, so I’ll do a little testing next week on the other locks and see it I get the same result on them.

You have two different profiles with two different Yale keys enrolled then?

Yeah pretty much.

What happened is, I cloned one Yale tag into my IAR glassie when I first got the Yale Doorman lock, and cloned another into a M1k card for hacking purposes. Then I transferred the M1k card into my flexM1 after I got that one implanted, but kept the glassie configured as a Yale Doorman tag in case the flexM1 disappointed. It didn’t, but I kept the glassie configured as-is, because the other applications I need it for only use the UID. So why not…

It’s strange actually, because the Yale tags have UIDs in a very narrow range. When I scan the flexM1 or the IAR, they come up with almost exactly the same UIDs, so it’s surprisingly hard to tell them apart at a glance:


Mine are worlds apart
(61EEEC54 and 99DCC619)

I can give you the dumps if you want to do some comparison digging

As I said, I have 3 locks, so I assume the keys are from different batches (afraid I’ve misplaced most of my keys, tho’, but have 2 dumps to share at least)

You could have cloned two tags from the same box :slight_smile:

No problem with the derail at all! It’s all interesting stuff. The back of the 2920 keypad has a small hole directly over the antenna PCB, through the plastic but obviously not going through the facia glass -

This is smaller than the coil on the PCB, would there be any benefit to opening it way out to the whole coil size? I have ordered the chips mentioned above, so they should be here in about 5 years (still blaming Covid) and that’s a great idea to try sticking them into a chicken!
Hell, I have a proper old fashioned butcher down the road, I might see if he can give me something exotic. Asking if he has “anything like human, it’s just for research though, honestly” might raise an eyebrow…

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What post?

Can’t remember…

aww… and here I was allready creating a thread whilst you are deleting stuff behind my back :stuck_out_tongue_closed_eyes:
@Pilgrimsmaster feel free to delete the thread I created :wink:

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