I am working with RFID-RC522 and Arduino UNO. I have check pin configurations again and again tried different libraries. It is not reading card and red led on RC522 is consistently on.
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Here's a picture of the card reader I have. If yours looks identical, then this library should work: https://github.com/ljos/MFRC522
The auth_read_write.ino sketch worked for me. Before you install the library, I recommend removing any other MFRC522 libraries from your arduino/library folder.
The only thing I did differently was used a 74HC4050 running at 3.3V between the Arduino and card reader. Some people claim you can connect the reader directly to the Arduino. I didn't want to take a chance of burning out the card reader so I used the 74HC4050.
Here's how I connected it:
Component markings and connections
|-------------------------------------------|
| SPI | UNO | 74HC4050 | RFID-RC522 |
|----------|-------|-----------|------------|
| SDA (SS) | 10 | 7 | |
| SDA (SS) | | 6 | SDA |
| SCK | 13 | 5 | |
| SCK | | 4 | SCK |
| MOSI | 11 | 3 | |
| MOSI | | 2 | MOSI |
| MISO | 12 | | MISO |
| IRQ | N/C | N/C | N/C |
| GND | GND | 8,9,11,14 | GND |
| RST | 5 | | RST |
| 3.3V | | 1 | 3.3V |
|-------------------------------------------|
