softserial to communicate with computer

Hello! I'm a newbie in arduino so please excuse me for the silly question if it is

I have arduino nano and need two serial ports to communicate with computer, I have one program "sitting" on one port and need another program to "sit" on another. The first program is proprietary and I don't have it's source code so I could add code from second program so they could share one port... Long story short - I need another serial port to communicate with computer on nano v4.

I've found NewSoftSerial library and going to do as follows: 1) in arduino code add serial like this: NewSoftSerial mySerial(4,3); 2) connect computer's TX -> D4 on arduino, RX -> D3

then start working with mySerial. Can I go like this? Or do I need to add some RC components? Sorry for the stupid question if it is, thanks!

I’ve found NewSoftSerial library and going to do as follows:

  1. in arduino code add serial like this: NewSoftSerial mySerial(4,3);
  2. connect computer’s TX → D4 on arduino, RX → D3

This will require chopping the end off a USB cable and identifying which of the 4 wires is TX and which is RX and which is ground, and connecting them to the appropriate pins (3, 4, and Gnd).

Can I go like this?

Yes.

Or do I need to add some RC components?

RC? What would you need radio controlled components for?

PaulS:
This will require chopping the end off a USB cable and identifying which of the 4 wires is TX and which is RX and which is ground, and connecting them to the appropriate pins (3, 4, and Gnd).

oh my, I forgot to mention, I was going to use pci serial adapter (based on NetMos Nm9835CV chip if this is important). I’ve soldered 9-pin wire to rs232 male connector and was going to identify which is RX TX and GND (I’ve found pinout, just to check it). Can I do the trick with this card or do I strictly need to use USB-Serial adapter? Thanks!

Serial output is typically +/-12V. Those voltages will toast your Arduino in nothing flat.

A google search for "NetMos Nm9835CV" turns up all kinds of driver software. This software will not make the serial port output voltages that you can input to the Arduino. You need hardware for that - a MAX232 chip.

The USB ports output the proper voltage already.

PaulS: Serial output is typically +/-12V. Those voltages will toast your Arduino in nothing flat.

A google search for "NetMos Nm9835CV" turns up all kinds of driver software. This software will not make the serial port output voltages that you can input to the Arduino. You need hardware for that - a MAX232 chip.

The USB ports output the proper voltage already.

Thank you very much, it's all clear now. I've measured output on that pci card and indeed there is 12 v there. I'll buy usb-serial converter so not to mess around with MAX232 as I'm a complete noob in electronics. Thanks!