A modern take on the classic PCF8574 IO expander, designed specifically to fit on an 8 channel relay board. It also has an extra ground row to make it super simple to make switch panels! The goal of the IOByte is to create a better breakout for the PCF8574 GPIO Extender mostly focused on quickly deploying relays and switch panels via i2c. The initial idea behind the PCB design was based on having it fit directly on a common 8-Channel relay board. Existing breakouts generally would require 10 DuPont leads (or other wire interface) to the relay board. Solder on a 10p female header, connect I2C and you have a super fast and cheap deployment. The IOByte can also act as a binary input device. The ground row of pins makes it easy to deploy simple switches connected from any of the 8 open-drain pins to ground. Quickly deploy switch panels with your favorite hardware.