They're reference designs for a reason.
A port is a small disc placed under the skin to allow easy access to veins for medication and blood draws, reducing the need for frequent needle pricks. The insertion of a port is a quick procedure ...
This library gives easy control over the 8 pins of a (I2C) MCP23008 chip. This IC is strongly related tot the MCP23017 I2C port expander - https://github.com ...