【通信应用笔记】18位硬件和软件的指导增强的端口扩展键盘控制器.pdf AN3245 Application note A hardware and software guide for the STMPE1801 Xpander Logic 18-bit enhanced port expander with keypad controller Introduction The STMPE1801 is a GPIO (general purpose input/output) port expander able to interface 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 highlights the guidelines and information complementary to the STMPE1801; Xpander LogicTM 18-bit enh……