I am planning to use the Arduino as a replacement for a USB-Controlled Digital I/O device, which will be integrated into an existing C++ software package that I created. I understand that the Arduino acts like a Serial device to a PC. Every serial device can be controlled by its own set of commands and queries. However, the only commands and queries that I've found for the Arduino involve flashing one-time programming to it from the "inside" rather than providing real-time automated control from the "outside."

Can anyone tell me where can I find the complete list of Arduino serial command & query strings? Thanks.


2 Answers 2


The Arduino has no "standard" serial commands.

It is a programmable device which you have to program yourself. The only serial commands it can respond to are the serial commands you yourself program it to respond to.

There are projects around that provide a serial interface, but they are generally designed for one specific purpose, and the commands or protocol they implement are unique to that project.

The closest to what you are asking for is the Firmata firmware, which comes with the IDE, and can be used to control the Arduino through the serial port using programs on your PC.


Arduino is a computer. It is designed to run programs that interact with real world via multiple digital and analog pins.

It has a USB port (Arduino UNO) to connect with a desktop computer. You develop programs for Arduino with your Windows/Mac/Linux computer and download them to Arduino vía USB port.

So, Arduino do only what you program it to do. No command or query string involved.

An Arduino sketch access use the USB port as a Serial port. It's normally used for debugging purposes (sending back information to the PC) or for configuration/control, if you want not to add a keypad and display to your project.

Some Arduinos doesn't comes with a USB interface.


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