Readers of contactless cards (RFID cards)

Hello! Guys, need help .. I can not read a card Available Arduino Uno, RFID reader to be connected on the rx, tx Tell me how to do it correctly Used here is such a reader - http://www.elics.ru/files/more/instruction/u-prox.pdf

Sorry, but my Russian is not up to understanding the details that you linked to.

Just tell me how to connect the reader to the Arduino via the TX, RX, and how to write code?

A guess :

Connect Tx on the reader to Rx on the Arduino Connect Rx on the reader to Tx on the Arduino

Set the serial baud rate using the Serial.begin() method In the loop() function, when serial data is available read a byte and do whatever you want with it.

Of course, the reader may not even be a serial device as I can't read the details.

What kind of details you need? I'll try to answer your questions

Try what I suggested, device Tx (Data 1) to Arduino Rx, device Rx (Data 0) to Arduino Tx, device GND to Arduino GND, Serial.begin(2400); in setup() then

If (Serial.available()
{
  Serial.println(Serial.read());
}

in loop().

If none of this makes any sense then you need to do some simpler projects first.