I have a project that requires 4 different RFID-RC522 readers. The RFID-RC522 has the following pins:
I have read that the SDA pin is used for selecting the active device, So I'm thinking that these devices can share data pins. Is it possible to connect multiple RFID-RC522 readers to the same 3.3V, RST, GND, IRQ, MISO, MOSI and SCK pins if you use a different pin for each SDA? If so, this would save me a lot of pins. So far, I have only seen direction on how to connect one RFID-RC522 to an Arduino.
I'm using the MFRC522 library. It appears to only support one reader because it only allows one SS pin to be identified in the constructor, and offers no way to change it later. An I missing something or do I need another library?