Trasferring Arduino chip from prototype platform to a PCB (Serial Communication)
If you're using the Arduino Uno, or any of the older versions, that still used the Atmega328 chip in a DIP package, you can do this.

You will need 1 of 2 things for serial communications with your computer.

If your computer has a hardware serial port built in, you will need to use a TTL-to-RS232 level converter chip.

If your computer does not have a hardware serial port, you will need a USB-to-serial chip.