The ADP-GPION four-way or eight-way modules feature photodiodes and high current relay interfaces on each line to isolate the motherboard from potential damage caused by Electrostatic Discharge (ESD) voltages and other transients on lines that interface with the GPIO controller chip. GPIO peripherals vary quite widely.
Software controlled, they vary from a group of pins that can be switched as a group to either input or output or each pin can be set up to accept or source different logic voltages, with configurable drive strengths and pull up/downs. With voltages as low as 10 V able to damage semiconductors, this issue is increasingly significant when embedded motherboards are incorporated in industrial control equipment, kiosks and other systems. As a separate but related introduction, a new software utility, which gives easy access to the GPIO bits and the watchdog timer, is available to simplify programming of the Winbond GPIO chip used on many motherboards.
The AS-RS485 converts two RS-232 ports to two RS-485 ports. Requiring a 5 V DC input, this board provides complete galvanic isolated and features full duplex RS485 transceivers. RS485 uses differential signals and is ideal for systems where the ground loop is broken allowing for large common mode voltage variation.