I made a PCB board that can handle measurements and control from a web application made in Java (Vaadin) and I want to connect the RX and TX pins of that PCB board to my Raspberry Pi 4B.
I tried to connect RX -> TX and RT -> RX between the PCB board and the Raspberry Pi 4B. Then I'm using jSerialComm library for communication in Java. But it did not work for me.
Is jSerialComm library only made for "USB"-communication and not using the RX and TX pins as well in Raspberry Pi?
Else, my PCB board works well with a FTDI232 chip between the PCB board and the Raspberry Pi USB port.