HF-PCAL95555 Documentation

Welcome! This directory contains step-by-step guides for installing, building, and using the HF-PCAL95555 library – a hardware-agnostic C++ driver for the PCA9555 and PCAL9555A 16-bit I/O expanders.

The driver auto-detects which chip variant is connected and enables features accordingly. Standard PCA9555 features work on both chips; PCAL9555A-only features (pull resistors, drive strength, input latch, interrupt mask/status, output mode) degrade gracefully on a PCA9555.

📚 Documentation Structure

Getting Started

  1. 🛠️ Installation – How to integrate the driver into your project
  2. ⚡ Quick Start – Minimal working example to get you running
  3. 🔌 Hardware Setup – Wiring diagrams and pin connections

Integration

  1. 🔧 Platform Integration – Implement the CRTP I2C interface for your platform
  2. ⚙️ Configuration – Configuration options and Kconfig settings

Reference

  1. 📖 API Reference – Complete API documentation (43 methods)
  2. 💡 Examples – Detailed example walkthroughs (comprehensive test + LED animation)

Troubleshooting

  1. 🐛 Troubleshooting – Common issues and solutions

🚀 Quick Start Path

New to PCAL95555? Follow this recommended path:

  1. Start with Installation to integrate the driver
  2. Follow Hardware Setup to wire your I/O expander
  3. Read Quick Start for a minimal working example
  4. Check Platform Integration to implement the I2C interface
  5. Explore Examples for more advanced usage

💡 Need Help?

  • 🐛 Found a bug? Check the Troubleshooting guide
  • ❓ Have questions? Review the API Reference
  • 📝 Want to contribute? See the contributing guidelines in the main README

Navigation ➡️ Installation

Table of contents