One ring to enter the hostel, or how I spoiled the ID EM reader

Access to my hostel, as well as to many buildings, is carried out using proximity-cards. Many simply apply backpacks to the turnstile in the hope that the pass has not collapsed anywhere, and the turnstile will determine it. I was so unlucky and often had to rummage through my bag in search of this stupid card. More than once thought came to just sew a pass, but the fact that “a student is obliged to present a pass at the first request of protection” stopped, and the continuous shifting during passes without a backpack did not bring joy. Therefore, one winter day I ordered the easiest Reader & Writer with Ali (guessing the frequency and standard) with a dozen consumables. A bunch of China Post and Russian Post delivered the package to Peter in a couple of weeks. After messing around with the Chinese software, three clones of my pass were glued to a backpack, two cards were put in reserve, and five trinkets went to the shelf (locked on the record).



But soon I was tired of putting the backpack to the turnstile. While you take them, while you put them, while you put them back on ... I wanted something more simple and elegant to implement ...
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And here I came up with a simple idea: a ring. Remembering an article about a similar experience , I figured that the transmitter is not so big and can be hidden in a ring. Didn't anyone think of such an idea, and the Chinese have not yet put the technology on stream?

It turns out that there is such a product as the Gala Ring G1 - a stylish, skin-covered ring containing two NFC tags. Alas, but as far as I know, 125KHz RFID Reader is not able to read the NFC tag.

Recently, several Chinese rings came to me: absolute power and “Titanium”.

I decided to modify one of them: hide the board itself under the ring (it is a bit large to me), and use the antenna to “lengthen” it.

The first step was to get the chips themselves. Remember two deferred cards? Using the experience of the jmeprogrammer , I decided to just soak the cards and get the chip. It was not there ... My cards were made of 3 layers of plastic: a protective plate, a layer with an antenna and a chip, a protective plate. The protective plates easily detached, but then the problems started ...

The antenna and the chip were fused into the middle layer. What to do when you need to get what you kindly do not want to give? Of course, use a soldering iron!

The process was difficult: the plate did not want to stratify. I just had to burn out the metal from plastic ...

The first pancake came out lumpy: I did not manage to rescue the antenna with the chip and had to improvise.

Of course, my fake was not identified by the reader. I decided to break one of the blocked trinkets and remove the chip with the antenna from it (you would know how durable the plastic is there). Pliers and a little effort: after a couple of minutes you could contemplate the insides of the "device".

Having extracted the chip, I decided to test its performance by simply considering it. What could be easier? During the transfer process, I damaged part of the antenna and did not notice it. The program issued a read error and lost the connection to the device. No more Reader & Writer was defined for her, and I lost the ability to read / write RFID tags. Therefore, while I wait with this venture. Although you can try to buy a new Reader and to him "bare" chips without a shell .

PS It turns out that I was looking bad and there are RFID animal ring . Although the price they have biting, and I am not an animal.