Which NFC reader would you recommend for reading NFC implants?

edited November 2019 in RFID/NFC

I've tried a few off-the-shelf NFC readers to read the implant in my hand, but I'm not terribly impressed with most of them. So far, I've tried:

  • ACS122U: decent range, easy-to-find sweet spot, convenient.
  • ACS122T: harder-to-find sweet spot, the reader must be on the skin, but if the device is attached somewhere convenient and with practice, it's usable.
  • uTrust 4700 F: sort of meh: usable but not convenient.
  • TWN4 Multitech aka TWN4 Mifare NFC: horrible. Poor range with a good NFC credit card, reads my implant once in a blue moon if I ram my hand forcibly against the shell and hit the sweet spot within a fraction of an inch. Totally unusable.

So far then, the best results I've had have been with the ACS devices. So I have a dozen going around the office and they do the job. I have a few other brands/models on order for evaluation, but I'm wondering which you would recommend for best range and easy, non-tricky hand placement.


  • If you want easy reading and actual security isn't really a consideration you should consider switching to a 125kHz tag. They have much greater range and accept a larger range of orientations. I've used the Seeed Grove 125kHz reader with a μcontroller for some of my projects. There are also tons of other standalone readers out there, since it's a legacy tech.
  • Yes, a LF chip is next on my list. I'm still trying to decide which model, for the sake of maximum compatibility with readers that are out there (EM4102 / 4200 probably), whether there are models that I can change the UID of - and without risking bricking it - and where to implant it so it's safe, convenient and leaves real estate for more chips later on.

    That's a fun project for some other time :) For now the Mifare works well enough for my purpose, but I'll admit that if there's an exceptional commercial reader out there in terms of range, I haven't found it yet. Of course, when I have some time, I can always crack out the soldering iron and roll my own...

  • edited December 2019

    I implanted a RFID implant today (EM4200, on the larger size). Indeed the range is excellent, even through my still-swollen hand. As a bonus, I've found a use for my TWN4 Multitech reader: while it's completely hopeless with my NFC implant, it works dandy reasonably well with the RFID one.

  • Is it a straight EM4200 chip, or is it a reprogrammable ATA5577 currently set up to emulate an EM4200?
  • Not sure. The German distributor I bought it from has this annoying habit of renaming the devices he sells with his own simpified naming scheme. But the specs say it supports 100,000 writes, so I'm guessing it can be rewritten, logically enough.

    I'm not really interested in writing to that one but I'll goof around with it.

  • Yeah, looks like you would need a proxmark to properly identify the chip. Oh well, as long as it works for your use case. Glad you got improved range.
  • edited December 2019

    A Proxmark is on by to-buy list. But with the xmas season idiocy in full swing, if I order now, I'll get it in January anyway. So I might as well wait a bit to order it.

    But yeah, right now the chip registers on the readers I need it to register on, so it'll do fine as it is for the time being.

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