Turn Arduino Into USB to TTL Adapter With 1 Wire

A standard Arduino includes a USB to TTL chip
so we can make it as a adapter

what we have to do is to plug one wire between RESET & GND

easy, dosen't it?

Now, you can use RX (pin 0) and TX (pin1) to communcate~~

after you plug the wire,
this change the MCU into "Reset Mode"
so now only  FTDI chip work on your arduino board!!