Specification: _x005f_x000D_ Product Name: PCF8574T Module _x005f_x000D_ Size: 38 * 17mm/1.49 * 0.66inch _x005f_x000D_ Weight: 4g _x005f_x000D_ Module functions: _x005f_x000D_ The I/O expansion module based on the I2C interface can expand 8 I/Os using 2 I/Os. Supports cascading and can use up to 8 modules simultaneously, expanding to 64 I/O. Set the module address through a dial switch. _x005f_x000D_ The wiring diagram and test code for Arduino development board are as follows: _x005f_x000D_ Every 2 seconds, let P0~P7 ports output high and low levels. Turn all 3-digit dial switches to 'ON'. At this time, the module address is 0x27 _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Note: _x005f_x000D_ Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! _x005f_x000D_ Please allow 1-2cm measuring deviation due to manual measurement. _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Included: _x005f_x000D_ 1 x Module 1. Module Functionality: The IO Module is based on the I2C interface and allows for the expansion of input/output capabilities. With 2 I/O pins, it can be expanded to control up to 8 additional I/O pins. It also supports cascading, enabling the use of multiple modules concurrently to expand up to 64 I/O pins. The module address can be easily set using DIP switches. 2. Wiring Diagram and Test Code for Arduino: The module can be seamlessly integrated with for Arduino boards. By following the provided wiring diagram and utilizing the test code, you can quickly start experimenting with its features. The test code included allows you to toggle the output states of pins P0 to P7 every 2 seconds, alternating between high and low levels. When all three DIP switches are set to 'ON' position, the module's address is automatically set to 0x27. 3. Practical: The IO Expansion Module (PCF8574T) is practical. Its I2C interface and ability to expand I/O pins provide enhanced control capabilities for electronic projects. The cascading feature enables the simultaneous use of multiple modules, significantly expanding the number of controllable devices. 4. High Quality: PCF8574T I/O module is made of high quality material, durable for long term.