EL-Cheapo RFID Reader:
- Mix 1 part MFRC522 Module from Aliexpress , with 1 part CP21xx also from Aliexpress.
- Cut trace connecting pin EA(pin 32 (next to pin 1)) to 3V3 (of the MFRC522 chip). Connect it instead to GND enabling UART communication mode.
- Sprinkle 2 drops of krazy glue and mix modules together.
- Leave covered overnight or a few hours till glue solidifies.
- Solder wires connecting relevant pins together.
To use your El-Cheapo RFID reader, go to Github and clone that repository. That fork of libnfc is capable of reading uid, sak, and Rats from a single card in the field. It however needs help to handle authentication for Mifare, optimization for uart communication, and collision handling for multiple tags. Have fun!