This document is a hardware and software guide for the STMPE1801 Xpander Logic™ 18-bit enhanced port expander with keypad controller. The product is a GPIO (general purpose input/output) port expander that can interface with a main digital ASIC via a two-line bidirectional bus (I2C). It offers the flexibility to be configured into a 10x8 matrix keypad controller for QWERTY keyboards and general purpose inputs/outputs. This document provides guidelines and information complementary to the STMPE1801 datasheet, which is necessary for the successful design of STMPE1801 in applications. The first part of the document highlights information on the hardware including external components/connectivity, power, etc. The second part of the document focuses on information regarding the software, in which programming sample codes are shown.