An MCP expander is an integrated circuit that increases the number of available input/output (I/O) pins on a microcontroller or other digital logic device. It achieves this by using a serial communication protocol, such as I2C or SPI, to communicate with the host device, effectively extending the available I/O resources. For example, a microcontroller with limited I/O pins can control numerous LEDs, read sensor data from multiple sources, or manage complex button matrices by employing one or more of these devices.
The employment of such expansion modules offers significant advantages in embedded systems design. They can simplify board layout, reduce the overall component count, and enable the implementation of more complex functionalities within resource-constrained environments. Their adoption dates back to the early days of microcontroller technology when available I/O resources were significantly limited, driving the need for efficient I/O expansion solutions.
