I want to set up 2 serial comm ports to communicate between one PI3B+ and one Teensy3.2. I want to use the two spare USB ports on the Pi, one for each comms port and connect them to two of the TX, Rx pairs on the Teensy. I need to communicate at 155200 baud. SO I am looking for a USB cable to plug into the PI and the other end of the USB cable needs to have a 3V3 logic level Tx, Rx, Gnd, Vcc pins to go to the teensy. I need two of these. Do you sell something like this? I would like to place an order this afternoon if this is a suitable solution.
Second question - I want to write a program in C to run on the PI which will run a loop which will read chars on the serial port and write chars to the serial port. How will I simply be able to access the USB serial ports and identify and set the parameters in C? This should be a simple program like 10 lines of code long or so.
I think this is a very simple question and quick to code and put together. But the type of question that can take weeks to do if one does not know some little thing that is not obvious to find.