I would like to connect the serial port on the 3pi+ to an program running on the PC. When I connect the 3pi+ to the PC, COM4 shows up and that is what I used to download the 3pi+ program from Arduino. Once up and running, I want to communicate to the 3pi+ from a C# application. The C# program is going to try and set up the COM4 with a baud rate of 230400 and 8N1. Since this is actually a USB port that looks like a com port, does it even care about baud rate and other settings? Should I be able to use this com prort just like any other USB to serial device?
Should I be able to use this com prort just like any other USB to serial device?
Yes, that should work.
The C# program is going to try and set up the COM4 with a baud rate of 230400 and 8N1. Since this is actually a USB port that looks like a com port, does it even care about baud rate and other settings?
That should be correct as well. The only special baud rate for USB based Arduino boot loaders is 1200 baud. Connecting at 1200 baud to such an Arduino capable device typically makes it reboot into the boot loader. That is how the Arduino IDE gets the device ready for it to upload new code.
Good luck
Yes, you should be able. Just make sure that the baud rate and other settings are set up correctly on both sides of the link, and that the data being sent and received is in a format that both sides can understand