Connection to digital pin and use of SoftwareSerial

am writing you from an Italian additive manufacturing company since we are using the microcontroller A-Star 32U4 Mini SV.

We setup a connecyion between the microcontroller and an RFID/NFC reader as in the attached images extracted from the schematic of the entire project. Since we want to control that RFID module using the arduino library SoftwareSerial, are the connection good? In particular we want to use the following connection, where NFC_RX_PIN=18 and NFC_TX_PIN=19.

SoftwareSerial b1Serial(NFC_RX_PIN, NFC_TX_PIN);

Could you please tell me if we are doing something wrong or everything is ok? At the moment we cannot control the RFID module and we would like to know if the connection are right or not, and, according to your expertise, if it is possible to use the SoftwareSerial library using the pin 18 and 19 as in the attached schematic

I found this link
It says that pins 18 and 19 cannot be used for Software Serial on Arduino Leonardo which is based on AtMega32U4 as A-Star 32U4 Mini SV.
Is it like that? I cannot use such pins for software serial communication?


You are correct; pins 18 and 19 on the A-Star 32U4 (or ATmega32U4) do not support pin change interrupts required to use the SoftwareSerial library. According to the library’s documentation:

- Amanda

Thanks a lot for the answer!
We will made the necessary modification to the board we have and I will let you know if we can control our RFID module using two of the other available pins for software serial.


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