robtillaart/pcf8574

How robtillaart/pcf8574 works

PCF8574 is a small Arduino library for controlling an eight-pin I2C expander. A sketch configures the library and uses its API for pin-level or whole-port reads and writes; optional helpers support button reads, array transfers, and output-bit transformations. The implementation buffers input and output values and communicates through Arduino’s Wire interface with the expander. The README says interrupt handling is user-owned, not implemented by the library. The graph reflects the sampled core source; examples and unsampled code are not mapped.

Main entry points: PCF8574.cpp Pin and port I/O · PCF8574.h PCF8574 API

Components 10

Other components

Arduino sketch
PCF8574 API PCF8574.h
Device setup PCF8574.cpp
Pin and port I/O PCF8574.cpp
Array transfers PCF8574.cpp
Button reads PCF8574.cpp
Output transforms PCF8574.cpp
I/O buffers PCF8574.cpp
Arduino Wire
PCF8574 device

Connections 10

Arduino sketch → PCF8574 API: uses README.md
PCF8574 API → Device setup: implements PCF8574.cpp
Device setup → Pin and port I/O: initializes via PCF8574.cpp
Pin and port I/O → Arduino Wire: transfers I2C PCF8574.cpp
Array transfers → Arduino Wire: transfers I2C PCF8574.cpp
Button reads → Pin and port I/O: calls PCF8574.cpp
Output transforms → Pin and port I/O: writes via PCF8574.cpp
Pin and port I/O → I/O buffers: updates PCF8574.cpp
Array transfers → I/O buffers: updates PCF8574.cpp
Arduino Wire → PCF8574 device: communicates with

Drawn by GitDiagram on November 15, 2026 from the repository's file tree, README and source files. Read as Markdown ·