Tring to use MarlinSerial, where does it go out to?
I'm making modifications to the Prusa Firmware and in part of it I want to send text out through the TX pin on the J19 socket of the Einsy Rambo board. That's where I THINK an instruction like MarlinSerial::println("Hello World"); should send the text.
I've configured a small Arduino, the Nano Every board, with a simple program that examines that board's RX pin to receive data coming in, and I've connected that board's RX pin to the Prusa's Einsy Rambo board's TX pin on the J19 socket (as well as connecting the GND pins between the two boards).
So my Prusa firmware is (trying to) send text out through the Einsy Rambo board's TX pin on its J19 socket and my Arduino is trying to receive that text via the Arduino's RX pin.
But it's not working.
Am I doing something wrong?
If my new instructions in the Prusa's firmware, i.e. my calls to MarlinSerial::println("Hello World") is NOT sending the text out through the TX pin on the J19 socket, HOW DO I get it to do that? Or alternatively what pin SHOULD I be connecting to in order to receive the text from my new instructions on the Prusa's firmware?
Or is there something else I need to do, to set up or something?
What's the conventional way to send text out of the firmware to another board?
PLEASE ! ! ! I need help
I'm looking all over and cannot find how to do this. It SEEMS that two pins on the J19 connector are INTENDED for serial communications, but nothing is actually set up by default in the Prusa firmware to do that.
It SEEMS that the PA0 and PA1 pins on the Einsy Rambo board MIGHT BE intended to be connected to the TX and RX pins on the J19 connector, but it also appears that nothing in the Prusa firmware actually sets up anything for SERIAL_PORT_2, or MSerial2, which are talked about by responses from ChatGPT about all this.
PLEASE, there must be someone who has successfully set this all up, as it SEEMS that the EInsy Rambo board EXPECT the use of a second (UART) means of communication via the TX and RX pins on the J19.