NFC tag reader with cheap NFC keychain

Hi everyone,

I did not find an answer on my question about tags in HA, thus this question.
What I would like to do is the following:

Add a NFC chip reader somewhere in the house to disable/enable my alarm.
I would like a simple way for my neighbour or parents to enable/disable the alarm, when I am on a vacation for example. For this I would like to give them a cheap NFC keychain.

Is it possible to use a cheap NFC keychain, program it via homeassistant and then give them to some people to disable/enable the alarm ?

Thanks in advance,

Or buy the kit:

Found here:

I’ve seen those blogs/sites, but it was not very clear imo.

I want to buy that NFC reader (the prebuilt kit), but wanted to know for sure if I can program a NFC keychain with HomeAssistant and than give some those keychains to some people to enable/disable an alarm for example. Do they need to home assistant app or not ? I suppose and hope not ?

Other question: can I just buy these and they will work with that reader ? 10 NTAG213 NFC Sleutelhangers - - NFC Tags Kopen

You don’t program the keychains, it’s the ESP/Home Assistant you program to know the keychain.

So yes you can buy compatible keychains and distribute them, but I don’t know if the linked is compatible.

Keep in mind that copying a NFC/RFID tag is pretty easy. So to use them for your alarm or door lock can be less secure. Just a heads up.

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But most professional alarms also have NFC/RFID.
The benefit of this versus a professional is that you can configure it to be more secure with presence detection or double scan or something else.

Yes, sorry. This is what I meant with programming. I write my automation to them via the HomeAssistant app.

How do I know if a NFC chip is compatible ?

I know, i’ve thought about it as well. But was ok with it since I already have cameras as a first layer of security. Then they need to unlock my door / break in. After that, my door sensor and/or motion sensor will tell me there is movement.
You should indeed not trust on one layer of security. I would not use NFC to open my door for example.

But another question: can you prevent an NFC chip from being copied ?

Never leave the house or a Faraday cage :slight_smile:
I believe aluminum will significantly reduce the range, so a smal aluminum pocket to place it in?

As far as I know there is two frequencies, and I think, with my limited knowledge, if the frequency is correct then it will work.
But I have never really bothered to figure it all out.
I know at work our card reader is set up to read cards in a specific way, but I have no clue what that does or how it works.

Good. My advise always is be more secure (Read more comprehensive to break in) then your neighbors. :grinning: