So let’s say your using an Arduino in your project. You already have the hardware-based serial interface working with one portion of the project and need a second serial port for unrelated hardware.

I am currently using a PZEM-004T V4.0 100A connected to an Arduino Uno. I have connected the 5V and Gnd from the Arduino to the PZEM. I used the software serial example. PZEM TX is connected to pin 12 ...