So I am using an code and trying to communicate to another device using a usart. i have noticed that i must connect the transmit line of the usart to the transmit line of my rs232 level shifter to get things to display on my computer, why is this?
thank you.
I haven't seen one with a built-in transceiver.
It is a bit problematic since you use a different technology when you design a microcontroller than you use for a transceiver since one is optimized for high speed and low power with digital signals, while another is optimized for high voltages and good tolerance to ESD and other abuse.
But jsut as Erik noted: Todays traceiver solutions normally generates their own voltages, to allow them to be fed from a single 3.3V or 5V power source.