Two-way C++ communication over serial connection

Question

I am trying to write a really simple C++ application to communicate with an Arduino. I would like to send the Arduino a character that it sends back immediately. The Arduino cod

Answer 1

You should check if you have access to /dev/tty.usbmodem641. The usual way in Linux is to add the user to the proper group with adduser.

By the way, I know that to access the serial port, one needs to open /dev/ttyS0 (for COM1), until /dev/ttyS3. See for example this example in C.