Convert your Arduino to a USB serial interface

written at: 2024-10-26

For a small hacking project i needed to connect to a device via it's serial interface. Not having a USB to serial interface i started looking around the internet to buy one. After some thought, i started looking through my electronics and realized that many devices already have serial interfaces that can connect via USB. The most obvious one, being my Arduino.

After some Googling, i found two suggestions:

  1. Connect the reset pin with the ground pin and it works.
  2. Upload a sketch to accomplish the same.

I went with the second one, not wanting to risk any malfunction of my Arduino. Long story short, just upload this sketch in the Arduino IDE:

void setup(){ pinMode(0,INPUT); pinMode(1,INPUT); } void loop(){ }

After this, connect only the RX/TX pins on your Arduino. Remember that on the device you want to connect, the order is reversed.

You can now screen into your serial-USB Arduino that is connected via the serial RX/TX pins. I used it to hack a Lidl Zigbee Gateway.