Most of the communication between PC and I/O boards in robots will be through UART protocol. When both the devices communicate with each other, there should be some program in both the sides which can translate the serial commands from each of these devices. We can implement our own logic to receive and transmit the data from board to PC and vice versa. The interfacing code can be different in each I/O board because there are no standard libraries to do this communication.
The Arduino-ROS interface is a standard way of communication between the Arduino boards and PC. Currently, this interface is exclusive for Arduino. We may need to write custom nodes to interface other I/O boards.
We can use the similar C++ APIs of ROS used in PC in Arduino IDE also, for programming the Arduino board. Detailed information about the interfacing package follows.