Use of SoftwareSerial with A-Star 32U4 Mini SV

Other Hardware 3rd Party Boards
1

Hello, I am writing you from an Italian additive manufacturing company since we are using the microcontroller A-Star 32U4 Mini SV (Pololu - A-Star 32U4 Mini SV), a microcontroller by Pololu (https://www.pololu.com/) based on AtMega32u4.

We setup a connection 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.

RFID_sensor.png
RFID_sensor.png952×316 19.5 KB

2

is the HardwareSerial port occupied?

3

Yes, HardwareSerial port is used by a touchscreen.

4

According to what is reported here https://www.arduino.cc/en/Reference/SoftwareSerial, since the microcontroller Pololu A-Star 32U4 Mini SV is based on ATMega32u4 as Leonardo, apparently I cannot use pins 18 (RX) and 19 (TX). Am i right?

5

Sil83:
According to what is reported here https://www.arduino.cc/en/Reference/SoftwareSerial, since the microcontroller Pololu A-Star 32U4 Mini SV is based on ATMega32u4 as Leonardo, apparently I cannot use pins 18 (RX) and 19 (TX). Am i right?

You are right. The page you've linked gives you a list of the pins that you CAN use for software serial.

6

Thanks a lot for the answer. Could you please give an assurance that it is like that. Because if I cannot use use pins 18 and 19 for SoftwareSerial I must change my design...

7

The Arduino reference page says that you can't use those pins and you've tried those pins and they don't work. What more assurance can I possibly give you?

8

I just asked for some assurance since Pololu A-Star 32U4 Mini SV is based on ATMega32u4 and it is NOT Arduino. However it is exactly like that. A kind Pololu employee answer to my email and confirm that pins 18 and 19 cannot be used for software serial.