The PCF8574 IO Expansion Board I/O Expander Bus Evaluation Development Module provides eight general purpose input/output (GPIO) lines that can be controlled over the I2C bus from a microcontroller, singleboard computer, or other I2C master. It is designed for straightforward evaluation and prototyping, enabling you to add IO capability without dedicating additional MCU pins. Key benefits Easy IO expansion via I2C: Add eight digital I/O lines to your host without using native GPIO pins, freeing the controller for other tasks. Flexible addressing on the I2C bus: A0, A1, and A2 address pins allow multiple PCF8574 devices to coexist on the same bus, increasing your expansion options. Quick integration with common platforms: Suitable for development with microcontrollers and SBCs that support I2C, including Arduino, Raspberry Pi, ESP32, and similar boards. Compact, breadboardfriendly design: The module uses standard 0.1 inch header spacing for easy connection and breadboarding during development. Simple, reliable IO behavior: Based on the PCF8574 I/O expander, providing eight lines that can be configured as inputs or outputs to support a variety of digital signaling tasks. Built for evaluation and prototyping: The board is positioned as a bus evaluation and development module to help you test and prototype IO expansion quickly and efficiently. Key attributes Functionality: 8channel I2C I/O expander using PCF8574, enabling expansion of host MCU I/O resources. Compatibility: Designed for use with I2Ccapable hosts and common development platforms; supports multiple devices on the I2C bus via address selection. Size and form: Compact development module with standard 0.1 inch header compatibility for easy integration with breadboards and perfboards. Material and construction: Built on a standard FR4 PCB for reliable performance in a development setting; designed to be easy to wire and test on an I2C bus. Performance characteristics: Delivers eight I/O lines under I2C control, suitable for simple digital signaling tasks and prototyping; intended for evaluation and development workflows. What makes it unique Specifically packaged as a Bus Evaluation Development Module for the PCF8574 I/O expander, providing a straightforward, readytouse platform to explore IO expansion on the I2C bus without custom circuit design. Addresses the practical needs of developers by offering configurable I2C addressing and a compact footprint that integrates easily into standard prototyping workflows. Recommended use cases Microcontroller GPIO expansion: Use the eight IO lines to drive indicators such as LEDs or to interface with small digital devices, freeing other MCU pins for core processing. Multiinput reading on a single bus: Connect several pushbuttons, limit switches, or other digital inputs and read them over I2C, reducing the pin count required on the host controller. Simple IO interface for peripherals and sensors: Provide a convenient digital signaling interface to peripheral modules or sensors that require IO signaling without adding complex circuitry on the host. Notes on use The PCF8574 IO expander functions as a general purpose I/O interface; ensure your host system's I2C voltage and logic levels are compatible with the module's operating conditions. The address pins A0, A1, and A2 enable you to place multiple expanders on the same I2C bus, improving scalability for more complex projects. This description reflects the product's model, features, and intended usage as a PCF8574 IO Expansion Board I/O Expander Bus Evaluation Development Module, presenting its benefits, specifications, and practical applications in clear, professional language.