If we look at the schematic of Arduino, we will see that the RX and TX pins are connected to the FTDI chip (as we expected) (on Arduino board as pin 0 and pin 1) That means we can use those pins for using the FTDI chip itself. We generally use TX and RX pins for communication. This is needed for the USB to TTL converter and there are many ways that can set input as RX and TX. There are three ways to convert USB to TTL and they are extremely simple techniques.Connecting Reset and GND
We can connect Reset and Ground with the help of a jumper wire. Now you can use RX and TX pins for communication. Removing ATMEL Chip
Another way is to remove the ATMEL chip and then you can use RX and TX pin.Coding
Use this code and upload it to Arduino and there we will be no need to remove ATMEL chip and also not connect Reset and Ground.