The Arduino family of microcontrollers possess a reasonable collection of input and output capabilities. While there are different versions, each with some unique capabilities, most controllers have a USB port, some digital input and output ports, a few pulse-width modulated (PWM) digital ports, and some analog input ports. This code module programs the Arduino with a simple command/response language via USB providing access to Arduino's I/O capabilities.

This code was developed, tested, and is known to operate properly using these Arduino boards:

• Arduino Uno R3
• OSEPP Uno R3
• Arduino Mega1280
• Arduino Mega2560

The Arduino can contribute its collection of I/O capabilities to an external control system, such as EPICS [1]. To EPICS (or some other control system), the Arduino appears as an I/O controller. To interface with an external system, a generic command language, independent of the details of the external system, is programmed into the Arduino and the board communicates over USB. This project is only useful for those Arduino boards which have an USB port.