2 RFID Readers on 1 Nano


I am making a project designed to monitor the size of a queue of cars with RFID tags attached by using 2 RFID readers, one for entry into the queue and the second for exit.

The reader I am using is the ID-12LA RFID Reader ID-12LA (125 kHz) - SEN-11827 - SparkFun Electronics

Connecting one reader works perfectly and is working exactly as planned.

However I am having problems connecting two readers. I am using the library provided here Arduino RFID ID-12/20 Library - YouTube

The program allowed me to create two different instances of an RFID reader but when uploaded only one of them worked.

Is there a proper way I'm supposed to to this that I've missed? All examples available only involve a single reader.

There are a number of solutions to this:

  • Use a controller with multiple hardware serials like a mega 2560
  • use a rfid reader with a wiegand or i2c interface
  • Write your serial receive routine that locks on the first active interface and then returns. I have code for that but be aware that overlapping messages will be lost