NFC reader with Home Assistant

EDIT: Changed the title to fit the direction of this chat.

I thought it might be fun to get some smart outlets and light bulbs to mess with so I ordered some Kasa brand devices from Amazon which Home Assistant (HA) can control. HA can write to NFC tags so you can control your smart devices by tapping your phone to a programed tag. I was wondering if it is possible to use my NExT and this RFID USB reader (pictured below) to control these devices? The USB reader spits out 10 digits and clicks “enter” so maybe it could be plugged into a Raspberry Pi that issues a command to the HA hub once those 10 digits are entered? Not sure how that would work. All I know is that I want to control my lights and their programed scenarios with my NExT :sweat_smile:

You could do something on a raspberry pi sure. But I use home made versions of this and it works really well at my house. The nice thing is it’s already integrated so you don’t need to program anything your self.

If you want to use these USB ones for whatever reason you’ll have to make some code that listening and when a tag is read use the homeassistant rest API to trigger automations.

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Now that looks promising! I think I will try to build a couple :slight_smile: Thank you!

I even designed my own PCB to make them easy. But used esp32 not the 8266.


Looks awesome! How would I build one? Does it use the same firmware as the other one? Also any 3D files for a case?

This one was running some custom stuff since I was using spi not i2c. But I can make one that follows official guide and make a 3D modeled case for it. Give me like an hour and I’ll upload some board designs and 3D models for a case.


You are amazing!

Does anyone want anything extra on this board? Maybe power headers instead of USB power, or more LEDs? The buzzer is huge so I kinda just don’t think anyone should use those headers…

Also @amal I used the DT logo, if that is not cool I can remove it. I just have the QR code that links to this thread so I thought it would be kinda cool/let people know they are in the right place.


3D printable case for new board design.

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Everything looks great! I would add some “waves” on the case haha

I tried putting it over the reader area of the scanner. I am also including the cad files so anyone can change it in any way they want. I will probably do it in openScad next and make a case designer UI in openJScad so that people can design their own cases in the browser.

This is all of the cad files, board design files, all that kind of stuff if anyone wants to order some boards.
NCF reader (EDIT: Don’t use this, it going to go up on github with some edits to make it more awesome)
keep in mind I just made this and despite it being a simple board and me making a few working versions before this is still a test.


I that might cause confusion … the qr code is great… but putting the logo on makes it feel like a Dangerous Things product. I appreciate the inspiration behind it :slight_smile: I just think it’s probably not a good idea to label non-DT products with the DT logo though.

However… after thinking about it a moment… I mean if this is something you wanted to open source then we could make a repo on GitHub and it could be a DT community project?


Yeah opening it up would be a great idea. Maybe say “Community” in the white stripe?


That’s a great idea

kinda like this.

I added some stuff just to make things clear and for fun! (It’s all for fun isn’t it?) The DT and HA icons are only there because I wanted reason to test out exposing the copper in a cool way. So those are shinny ooooh ahhhh I tried to do it with the community logo but where it is makes it so the logo would actually end up being parts of the RGB led data line and yes that would work, but it isn’t smart.

You can also see that I added power headers if you want it to be soldered in power not usb. (also safer since no one would take the usb and re-flash the board) the buzzer is labeled but put under the reader since I imagine not many will use it and opt for LED instead. I also extended the led data out, power, and ground into their own sets of headers if you wanted to do a led ring, strip, or whatever.

component cost of this is about $7 I think.


I didn’t have anything going on today so here is a github link to the fun morning project if enough people want some maybe we do a community run to get the cheapest parts.


Part of the point of doing dangerous things community projects is funding runs like this. If it makes sense, DT can run a batch of these boards and put them up on the store so they are easily be purchasable by individuals. If we end up doing that, this would be one of the first examples of a community project being offered through the dangerous things storefront.


I think that would be awesome! Are you thinking just the board or possibly a kit with all the parts in it?

I have a design suggestion,

Since this may be used in place of an old alarm panel or similar may a suggest adding an AC/DC 12V regulator down to 5VDC (I presume?).

A wide input regulator would be even better, but all alarm panels I’ve come across are 12VAC.

If not the regulator itself maybe a common footprint where one can be installed?

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okay, I had to move some stuff around to make it work, but if we straight solder this to the board it will fit under the wifi board that stands a little bit high because of the headers. You will solder 12v to the back of the board where labeled.

I didn’t want that under the antenna so it did force me to move some stuff around on the cosmetic side. But now we have a larger QR code.